Browse Topic: Engine mounts

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Engine Flywheel Housing and Mating Transmission Housing FlangesJ617_202009 (Current)9/29/2020
This SAE Standard specifies the major dimensions and tolerances for Engine Flywheel Housings and the Mating Transmission Housing Flanges. It also locates the crankshaft flange face or the transmission pilot bore (or pilot bearing bore) stop face in relation to housing SAE flange face. This document is not intended to cover the design of the flywheel housing face mating with the engine crankcase rear face or the design of housing walls and ribs. Housing strength analysis and the selection of housing materials are also excluded. This document applies to any internal combustion engine which can utilize SAE No. 6 through SAE No. 00 size flywheel housing for mounting a transmission.
Automatic Transmission and Transaxle Committee
Develop the Methodology to Predict the Engine Mount Loads from Road Load Data Using MSC ADAMS and FEMFAT Virtual Iteration2020-01-14014/14/2020
Design of powertrain mounting bracket is always a challenge in achieving good NVH characteristics and durability with less weight. For this activity engine mount load is necessary to optimize the weight to meet durability and NVH targets. This paper introduces a new method to calculate engine mount loads from chassis accelerations. The method starts by measuring chassis acceleration near engine mount location, then reproducing the same chassis acceleration in Multi Axis Shaker Table (MAST), and finally extracting the load in engine mount using testing (using load cell). The MAST test actuator displacement input is imported into ADAMS and engine mount loads are extracted. The extracted loads are correlated with physical test results. The correlation includes load time history and peak-to-peak load range. It is recommended to implement this method in early vehicle design phases. Implementing engine mount bracket weight optimization is desirable in early design stages. To avoid MAST testing and then MAST simulation based on road load data, FEMFAT virtual iteration and MSC.ADAMS integration helps us to integrate the road load data into MAST input data. It is a promising methodology to facilitate data-driven design decisions to be made at early stages of the vehicle development cycle.
Anthonysamy, Baskar, N, Balaramakrishna, Londhe, Abhijit
An FxLMS Controller for Active Control Engine Mount with Experimental Secondary Path Identification2020-01-04244/14/2020
Active engine mounts (AEMs) notably contribute to ensuring superior performance of vehicle’s noise, vibration, and harshness. This paper incorporates a filtered-x-least-mean-squares (FxLMS) controller into the active control engine mount system to attenuate the transmitted force to the body. To avoid the error caused by substituting the load cell for acceleration transducer, the FIR model of the secondary path was obtained by experiment. Finally, a hardware-in-the-loop testing system is built to verify the performance of the active engine mount. It can be observed from the test results that the vibration is reduced notably after control, which demonstrates the effectiveness of the active engine mount and the controller in vibration attenuation.
Guo, Rong, Zhou, Ziwei, Chen, Hao
More sting for the STINGRAY19AUTP11_0211/1/2019
GM Propulsion engineers elevate the evergreen small-block V8 to new heights for its mid-engine Corvette mission. Instead of heaving decades of small-block V8 expertise out the window, GM Propulsion engineers led by chief engineer Jordan Lee leveraged past success to create a new-for-2020 V8. Known as the LT2, the 6.2-L V8 gives Chevy's all-new, eighth-generation 2020 Corvette more power (the most yet in the base Stingray), stirring response, and competitive fuel efficiency compared with the outgoing C7. And the small-block, with its single camshaft in block and two valves per cylinder, remains unmatched versus its rivals in three key metrics: bill of material, package efficiency, and the power-per-dollar quotient. It's the payoff for 65 years of continuously refining (and never giving up on) a brilliant original design.
Sherman, Don
The Challenge of Replacing Hard Chrome19AERP10_0310/1/2019
The search for a suitable replacement for hard chrome on aerospace components has been a key supply chain priority for aircraft manufacturers. This is because of the documented health risks to workers and the impact on the environment from exposure to hexavalent chromium, a carcinogen that occurs during the chrome plating process and is the most toxic form of chromium. As a result, chromium is a highly regulated chemical in major markets worldwide. In the European Union, hexavalent chromium falls under the domain of the EU regulation, REACH (Registration, Evaluation, Authorization and Restriction of Chemicals), which establishes guidelines for the safe use of chemicals throughout the supply chain. Chromium is also closely regulated in the United States by OSHA.
The Challenge of Replacing Hard ChromeTBMG-3535910/1/2019
The search for a suitable replacement for hard chrome on aerospace components has been a key supply chain priority for aircraft manufacturers. This is because of the documented health risks to workers and the impact on the environment from exposure to hexavalent chromium, a carcinogen that occurs during the chrome plating process and is the most toxic form of chromium.
Test Method for Measuring Performance of Engine Cooling FansJ1339_201909 (Current)9/30/2019
This SAE Recommended Practice is intended for use in testing and evaluating the approximate performance of engine-driven cooling fans. This performance would include flow, pressure, and power. This flow and pressure information is used to estimate the engine cooling performance. This power consumption is used to estimate net engine power per SAE J1349. The procedure also provides a general description of equipment necessary to measure the approximate fan performance. The test conditions in the procedure generally will not match those of the installation for which cooling and fuel consumption information is desired. The performance of a given fan depends on the geometric details of the installation, including the shroud and its clearance. These details should be duplicated in the test setup if accurate performance measurement is expected. The performance at a given air density and speed also depends on the volumetric flow rate, or the pressure rise across the fan, since these two parameters are mutually dependent. These parameters depend on the pressure drop across the radiator core and the ram pressure due to vehicle motion. For these reasons, the test procedure should be recognized as providing only an approximate measure of installed fan performance. Although the test procedure is based on running the fan with a motoring dynamometer, the actual installation can be used as a test fixture if an accurate torque meter is available. In this case, the same qualifications discussed apply. For the effect of a fan clutch in reducing fan use and power consumption, which is not a part of this procedure, refer to SAE J1342. Performance testing of electric cooling fan assemblies is covered in SAE J2867.
Cooling Systems Standards Committee
Engineering the 2020 CHEVROLET CORVETTE19AUTP09_019/1/2019
The eighth-gen (C8) Corvette is a creative mix of novel and traditional technical solutions unleashed at a shockingly low base price. Two days before the 50th anniversary of astronaut Neil Armstrong's leap for mankind and 10 years after General Motors emerged from bankruptcy, the camouflage was finally ripped from the eighth-generation (C8) 2020 Chevrolet Corvette. As widely anticipated, C8 now flaunts a mid-engine layout that ostensibly puts it on equal terms with the world's most venerated supercars. After six decades of experimentation and concept-car teasing, GM acknowledged that the new Stingray will enter production before year's end. The truly shocking announcement is a base price of $59,995 including destination, only $3,000 more than today's front-engine C7. Along with moving the cockpit forward 16.5 inches (419 mm) to facilitate shifting the engine rearward, the new Corvette is an innovative mix of novel and traditional engineering solutions.
Sherman, Don
Machine Learning Algorithm for the Prediction of Idle Combustion Uniformity2019-01-15516/5/2019
Combustion stability is a key contributor to engine shake at idle speed and can impact the overall perception of vehicle quality. The sub-firing harmonics of the combustion torque are used as a metric to assess idle shake and are, typically, measured at different levels of engine break mean effective pressure (BMEP). Due to the nature of the combustion phenomena at idle, it is clear that predicting the cycle-to-cycle and cylinder-to-cylinder combustion pressure variations, required to assess the combustion uniformity, cannot be achieved with the state of the art simulation technology. Inspired by the advancement in the field of machine learning and artificial intelligence and by the availability of a large amount of measured combustion test data, this paper explores the performance of various machine learning algorithms in predicting the idle combustion uniformity. The algorithms that are explored include Neural Network (NN), Support Vector Machine (SVM), Ensembles of Trees (EOT) and Gaussian Process (GP). The variables selected as inputs to these algorithms include BMEP, indicated mean effective pressure (IMEP), pumping mean effective pressure (PMEP), spark timing, crank angle at 10% fuel burn (Burn0010), crank angle at 90% fuel burn (Burn1090), and crankshaft timing at 50% fuel burn (CA50). The algorithms output the amplitude of 0.5 order, 1.0 order and the 1.5 order harmonics of the combustion torque. The results presented in this paper show the superiority of the Gaussian Process algorithm in predicting the combustion torque harmonics. Using this algorithm, this paper further investigates the sensitivity of the engine torque harmonics to the parameters, used as inputs to the algorithm, in order to establish potential design guidelines for upfront combustion system development.
Li, Xiaoqi, Zouani, Abdelkrim
Development of Parametric Tool to Design Base Frame for Cummins Marine Application Engine2019-01-07984/2/2019
A spread sheet based parametric tool is developed to design the base frame for a marine generator-set. Factors such as engine details, generator details, anti-vibration mount (AVM) etc., that determine the design of the base frame, are set as parameters in the spreadsheet. The spreadsheet has formulae to calculate channel specifications, and AVM deflections. It is linked to channel standards database and selects the optimal channel based on calculations. Similarly, the tool provides guidance in selection of AVM from supplier catalogues, helps to predict number of anti-vibration mounts required and their location on base frame. This spread sheet is integrated with a generic base frame 3D model and 2D print in “Creo 3d modelling software” (Creo), which is auto-updated based on calculated parameters in the spreadsheet. Using this tool, the user can generate a 3D-model and 2D print. This tool helps to standardize the design process and reduces design turnaround time considerably. The output of the tool and existing base frame designs were analysed using a finite element tool (ANSYS). Modal and static analysis were performed and results were observed to be within ± 15%. This tool will be developed further and validated for base frames in other applications.
Kumar, Mukesh, Rajasekhar, Neeraja, Pokharkar, Prachi, Mahanta, Bibhu, Saha, Rohit
Interior Sound Quality Refinement Base on Mechanism Study of Crankshaft Impact Noise2019-01-07724/2/2019
A rumbling noise is audible in a vehicle passenger compartment during acceleration. Mechanism detail of the rumbling noise is studied. A series of preliminary transfer path experiments investigation on chassis dynamometer shows that the interior rumbling noise is mainly induced by abnormal crankshaft impact at particular crank angle. Spectrum analysis indicates that high level half order harmonic components significantly affects the rumbling noise. Multi-body dynamics model of the powertrain is developed to further investigate the root cause of the abnormal crankshaft impact. Experiment results are used to verify the numeric model. High deviation of main bearing forces at the crank angle 0° to 180° after the Fire Top Dead Center of the no.l cylinder is considered to fundamentally induces the high level half order components. The force ripple coupled with the crankshaft resonance induces the crankshaft rumbling. Sensitivities analysis of various bearing seat structure, crankshaft structural parameters were carried out. The ladder frame, a stiffened crankshaft with bigger overlap and shortened the front end offset distance seem effectively reduce the rumbling impact and improve interior sound quality.
Su, Zhangming, Chen, Hanshuang, Yang, Qi, Kong, Dandan, Xing, Weizhe, Xu, Yanghui, Cao, Xuelu
A Lumped Parameter Model Concerning the Amplitude-Dependent Characteristics for the Hydraulic Engine Mount with a Suspended Decoupler2019-01-09364/2/2019
This paper presents a novel lumped parameter model(LPM) and its parameter identification method for the hydraulic engine mount(HEM) with a suspended decoupler. In the new model the decoupler membrane’s variable stiffness caused by being contact with the metallic cage is considered. Therefore, the decoupler membrane in the model can be taken as a spring. As a result, two parameters of the decoupler’s variable stiffness and the equivalent piston area are added. Then the finite element method is employed to analyze the suspended decoupler membrane’s variable stiffness characteristics under the contact state with the metallic cage. A piecewise polynomial is used to fit the decoupler membrane’s variable stiffness. To guarantee the symmetry of the stiffness, the polynomial only keeps the odd power coefficients. The other lumped parameters of the HEM, such as the elastic stiffness and equivalent piston area of the rubber spring, volumetric compliance of the fluid chamber, the fluid inertia and resistance of the inertia track are also identified with the finite element method for further numerical simulations. Finally a computer simulation under sinusoidal excitations of various amplitudes is carried out with the identified lumped parameters to obtain the dynamic characteristics of the HEM. The validity of the LPM is also experimentally verified with the same configuration. The results show that with the identified lumped parameters, the proposed LPM can accurately predict the amplitude-dependent dynamic stiffness and loss angle of HEM with a suspended decoupler, while the conventional LPM, by not considering decoupler membrane’s variable stiffness characteristics, cannot accurately reflect the dynamic characteristic this kind of HEM.
Zhou, Dawei, Zuo, Shuguang, Wu, Xudong
Prediction of Seat Rail and Steering Wheel Vibration at Idle Using Crank Drive and 16-DOF ADAMS Model2019-26-01811/9/2019
Due to the recent trend in auto industry to opt for higher power engines, causes increase in vibrations levels in the passenger’s compartment. This requires a better and comprehensive model to analyze vibrations from engine to seat and steering wheel much before the proto stage of development in the design stage itself. For this purpose, modelling is done in ADAMS multi dynamics and assuming the 16 degrees of freedom of the vehicle. Further, a crank drive model is developed to simulate engine excitation forces comprising unbalanced inertia forces and torque fluctuations and their effects seat rail and steering wheel vibration is derived. This tool is an attempt to predict such vibrations caused and assist in design enhancement and streamline the procedure.
Hazra, Sandip
Design Optimization of Engine Mount De-Coupler for Cabin Noise Refinement in Passenger Vehicle2019-26-01991/9/2019
Quieter cabins are indispensable in today’s evolving automobile industry. The effective isolation of vehicle noise and vibrations are essential to achieve the above. Since, low frequency powertrain induced NVH has been one of the major contributors affecting noise and vibration levels inside the passenger cabin. Thus, use of hydraulic mounts is a natural choice for all major OEMs. The objective of this study is to optimize the design of the hydraulic mount de-coupler unit, to reduce the abnormal noise felt inside the cabin. This condition was observed when the vehicle was driven at 20~30 km/h over undulated road surface, found very often in Indian drive conditions. Due to lack of accuracy and repeatability errors during NVH data acquisition in actual driving condition, the above road profile was captured and subsequently simulated in an acoustically treated BSR (Buzz, Squeak and Rattle) four poster simulator. Problem investigation and countermeasure validation were also performed in this facility. A significant improvement in cabin noise level by ~6 dB(A) in the problematic frequency zone, with the countermeasure, without negatively affecting any other NVH performance parameters, was achieved. A novel test methodology has been established for expedited root cause investigation & counter-measure validation of the problem statement. Design modification of the de-coupler membrane for eliminating such noise is a new approach.
Verma, Pallavi, Chatterjee, Joydeep, Bhadani, Priyesh, Ghosh, Chiranjit
Road Simulation Techniques for Reproducing Vehicle Behavior at Motocross Running on a Track2018-32-005110/30/2018
A Road Simulator was developed with the aim of reproducing actual vehicle behavior while running on motocross (MX) track in a laboratory. Vehicle behavior while running on an MX track is influenced by various inertial forces, such as jump landing, acceleration at full throttle, reduced speed at full braking and so on, and also load input from the rider to handlebars and footrests. As all influences must be considered, these inertial force and external force should be applied to a vehicle in laboratory tests. To reproduce various inertial forces such as falling inertia at jump landing, longitudinal inertia during acceleration or deceleration, and rider body action on the vehicle, Active restraint systems must be added instead of the traditional method of Road Simulator that controls wheel axle’s vertical and longitudinal directions with actuators. The number of hydraulic actuator was increased, therefore all actuators must be controlled to eliminate any interaction effect of other actuator load and action. Furthermore, introducing actuator control technology that separated Frequency Response Function (FRF) by each running event, eventually the reproduction of MX running in a laboratory test was successful. As a result, 5% or less of root mean square (RMS) error value has been accomplished by wheel axis load, acceleration and suspension displacement during the reproduction of MX running. Herewith, accumulated fatigue damage degree of each part of frame has also been reproduced with high accuracy. From the above, we have achieved replicated MX running behavior in indoor laboratory tests, namely we are able to produce stable durability tests without variables of course conditions such as rain, differences caused by rider variations, etc. Moreover the test has been able to run consecutively day and night, so the test period has been shortened. In addition, various mechanisms occurring on vehicle have been able to be understood in detail during the approach to reproduce vehicle behavior and load in laboratory testing.
Shimizu, Ryota, Sugita, Hisayuki
Reverse ThrustAIR6064 (Current)5/7/2018
Propulsion measurements and thrust methods presented in the current published versions of AIR1703 and AIR5450 place a primary focus on the engine reactionary force (thrust) acting to propel an aircraft in the forward direction. In contrast, this document addresses the use of the engine reactionary force in the opposite direction (reverse thrust) to supplement aircraft deceleration. This document’s application spans commercial and military transport turbofan engine applications for various engine and reverse thrust configurations. The discussion and examples primarily focus on separate flow exhaust turbofan engines. Piston and turboprop variable-pitch propeller blade applications are not covered. Although reverse thrust has been utilized for in-flight deceleration, primarily for short takeoff and landing aircraft and military fighter applications, this application of reverse thrust is only covered in a cursory manner.
E-33 In Flight Propulsion Measurement Committee
Frequency Domain Fatigue Analysis of Exhaust Systems2018-01-13964/3/2018
Today in the automotive industry, there is a continual reduction in available development time. There is also an urgent need to reduce cost and weight, to adapt to customer and legislation which drives to an increase in design complexity. These challenges are sometimes made harder by the late availability of hardware and this creates the need to extend and continually improve the established CAE methods which are used to develop automotive parts. This holds especially true in the field of exhaust systems and their components, which experience loads from various sources like temperature, engine or road. In the field of road excitation the use of dynamic transient simulation and subsequent damage calculation is state of the art in terms of simulations methodology. Nevertheless the problems of this method are the long calculation times and large scratch data requirements as well as the necessary precise knowledge of the test track profile, which is generally not available in early project phases or sometimes cannot be communicated by the OEM to suppliers. This lack of information results, in many cases, in the usage of simplistic, experience based static approaches that do not display the real dynamic behaviour and lead to over engineering. Frequency domain methods for fatigue analysis and/or for general random response analysis have experienced resurgence over the last years due to improved technology and better computational processes. In previous papers, frequency based fatigue methods have been successfully applied displaying good correlation with the time based approach. This paper will propose a possible alternative to the use of the transient method or other, simplified static approaches for the development of complete passenger car exhaust systems using the capabilities of a frequency based fatigue method in a realistic scenario, i.e. under multi-position and multi-directional excitation. The key steps of such a frequency domain analysis will be discussed in the following. The first step relates to the conversion of the multi-channel load time histories followed by the second step related to how boundary conditions are placed. Then, the frequency domain results are compared in detail with traditional time based results. At the end of the comparison, a detailed overview of the calculation time and disk space needed for both methods will be shown in order to demonstrate the real advantage in the use of the frequency base fatigue method. As a conclusion and outlook, the huge opportunities to improve the cooperation between OEM and suppliers without compromising any precise information about track profiles using the power spectral density PSD of the signals will be illustrated.
Leisten, Philippe, Bishop, Neil, Spieth, Arnulf
Challenges of Hydraulic Engine Mount Development for NVH Refinement2018-01-06814/3/2018
NVH refinement of passenger vehicle is essential to customer acceptance for premium or even mid-size segment passenger cars. Hydraulic engine mount is becoming common for these segments to reduce engine bounce, idle shake and noise transfer to passenger cabin. Modern layout of hydraulic mount with integrated engine-bracket and smaller size insulator has made it cost-effective to use due to reduction of cost gap from conventional elastomeric mounts. However the downsizing and complex internal structure may create some new types of noises in passenger cabin which are very difficult to identify in initial development stage. Main purpose of hydraulic mount is to provide high damping at low-frequency range (6~15 Hz) and to isolate noise transfer from combustion engine to passenger cabin within wide frequency range (15~600 Hz).This paper emphasizes on challenges and problems related to hydraulic mount development. Tuning of Hydraulic mount is required to avoid cavitation noise at low-frequency and also any abnormal noise due to hydraulic unit resonance at higher frequency. Design measures to curb NVH problems, e.g. cavitation noise, bump noise of mount stopper, resonance from hydro unit, at early development stage are explained in the paper.
Ghosh, Chiranjit, Parmar, Aashish, Chatterjee, Joydeep
Effect of Thermal Management on Engine Performance2018-01-02244/3/2018
The effect of engine coolant and oil temperature on the performance was experimentally evaluated on a Navistar 12.4 Liter engine. The engine speed and load selected for evaluation represented the engine conditions typically found during a Class-8 truck’s cruising operation. In order to study the effect of oil and coolant temperature in isolation, the production coolant-cooled oil-cooler was replaced with a separate oil and coolant conditioning system. The piston and liner surface temperature was also logged at select locations to provide solid temperature response to coolant and oil temperature changes. The engine tests showed that oil temperature variation had greater impact on the engine performance compared to the coolant temperature. This performance improvement came primarily from the lower combustion heat rejection and reduced friction at moderate engine loads. At higher engine loads the performance improvement was largely due to lowered heat rejection. Engine operation at elevated coolant temperatures resulted in slightly higher exhaust enthalpy with little or no change to the engine performance. The liner and the piston temperature provided continuous feedback and helped to successfully navigate the engine through these areas of elevated coolant and oil temperature.
Rajkumar, M., Vojtech, Ryan, Cigler, James
WHAT WE'RE DRIVING18AUTP02_152/1/2018
It isn't every carmaker that introduces its new model with a session on a tight and slippery test track. But when it's a 1955-kg (4090-lb) sedan with 450 kW (603 hp) and 850 N·m (627 lb·ft) available at the shove of a foot, it is a useful education. That's what Mercedes-Benz offers its U.K. buyers of the new Mercedes-AMG E 63 S 4Matic+.
Aircraft Engine Exhaust Nozzle System for Jet Noise ReductionTBMG-2767710/1/2017
A system of nozzles and pylons that redistributes jet exhaust noise sources upstream to reduce jet noise has been developed. Certain aircraft configurations install the propulsion engines above the wing or tail surfaces, or above the fuselage, or in some cases above the structure that is a blend of the wing and body or hybrid wing body aircraft. In these aircraft configurations, reducing noise propagation to the community below is possible by using the aircraft as an acoustic shield for the sources associated with the engine. The more difficult engine noises to be shielded are from the jet exhaust because they are typically distributed downstream, the equivalent of several engine nozzle diameters. This innovation redistributes jet exhaust upstream to reduce noise.
Aircraft Turbine Engine Pneumatic Component Contaminated Air Endurance TestARP4014A (Current)9/5/2017
This SAE Aerospace Recommended Practice (ARP) describes a method of conducting an endurance test using contaminated air when the applicable specification requires non-recirculation of the contaminants. The objective of the test is to determine the resistance of the engine mounted components to wear or damage caused by the contaminated air. The method described herein calls for non-recirculation of the contaminants and is intended to provide a uniform distribution of the contaminant at the inlet to the Unit Under Test (UUT). The UUT may require the use of a hydraulic fluid for actuation of components within the test unit. Contamination of the test hydraulic fluid is not part of this recommended practice. If contaminated hydraulic fluid is required by the applicable test specification, refer to MAP749.
AC-9 Aircraft Environmental Systems Committee
A Systematic Approach Towards Engine Mounting System Vibration Isolation Performance Validation in Commercial Vehicles2017-28-19287/10/2017
Engine mounts and mounting brackets play a critical role in determining NVH performance of a vehicle. A lot of work has been done in the area of virtual simulation using FE models to study engine mounting system performance and its impact on vehicle level performance. An overall approach towards engine mounting system validation at vehicle level is also very critical to validate simulation results in a prototype based on which further refinement work will be carried. In this paper a detailed procedure for engine mount and mounting bracket physical validation at vehicle level is presented. Various tests to be performed at vehicle level to quantify engine mount and mounting bracket performance parameters is discussed in detail along with measurement procedures and techniques. Test results are interpreted and its impact on overall performance is also explained. These test results will help design engineers to further improve engineering parameters of mounts and mounting brackets. An attempt is also made to integrate impact of engine mounting system performance on vehicle level tactile vibrations. Adherence to this systematic approach will reduce the lead time of development and provides opportunity to identify key area to concentrate in engine mounting system design at early prototype stage.
Channamaneni, Rajesh Babu, Kannan, P, Padavala, Prasad
Optimisation of Engine Mounting System for Reduction in Lateral Shake and Drive Away Shudder on Vehicle2017-01-18226/5/2017
In this study we will be discussing two issues related to vibrations which effect car owners. The first one, called lateral shake, can be described as a lateral vibration felt by customer in low speed of around 1200rpm, when vehicle shakes severely in Y-direction. The vibration is significantly felt at the thighs of passengers. A 16DOF rigid body model is established to simulate the power train & body system. The second vibration issue, called drive away shudder (also known as clutch judder/chatter/shudder) is a vibration felt by customers at the time of marching off. The vibration is significantly felt at the time of clutch engagement as a shiver in vehicle. While the common solution of shudder is to optimize clutch friction & engagement, in this study solution has been provided by optimizing the power train mounting system. Clutch shudder is observed on a medium sized car when driven in the range of 10-20 Km/h. The design of powertrain mounting system has been modified to achieve the reduction in above mentioned vibrations. The pros & cons of the suggested change in mounting system on the overall NVH performance is also discussed.
Agarwal, Kopal, Hazra, Sandip
Magnetic Actuators for Active Powertrain Vibration Control2017-01-18296/5/2017
The new fuel efficiency and emission standards have forced OEMs to put emphasis on different strategies such as engine downsizing, cylinder deactivation… Unfortunately these new technologies may lead to increased powertrain vibrations generated by the engine and transmitted to the chassis and the car cabin, such that their reduction or elimination has become a key topic for the automotive industry. The use of active engine mounts, acting directly on the fluid of an hydromount, or active vibration dampers, acting as an inertial mass-spring system, are very effective solutions, particularly when using electromagnetic based actuators. Nevertheless, all electromagnetic actuators technologies are not equals and the choice of such actuators must be considered carefully by taking into account the full performances and the overall cost of the solutions. This paper presents an electromagnetic actuator technology, that can be considered as the best tradeoff between performances and cost. Comparisons with existing solutions currently proposed by automotive suppliers will also be shown.
Loussert, Guillaume
The Impact of Switchable Hydromount during Idle and Ride Performance of Vehicle2017-01-18266/5/2017
Engine mounting system maintains the position of powertrain in the vehicle with respect to chassis and other accessories during inertia, torque reaction loads and roadway disturbances. The mounting system also plays a role in terms of isolation of the rest of the vehicle and its occupants from powertrain and helps in maintaining vehicle ride and handling condition. This paper investigates the performance comparison between hydromount and switchable hydromount during idle and ride performance. The optimization scheme aims to improve the performance of the mounting system in order to achieve overall powertrain performance and NVH attribute balancing through switchable mount technology.
Deshmukh, Sagar, Hazra, Sandip
Optimization of the Powertrain Mounting System via DOE Method2017-01-19076/5/2017
The vibration isolation performance of vehicle powertrain mounting system is mostly determined by the three-directional stiffness of each mount block. Because of the manufacturing tolerance and the coupling effect, the stiffness of mounts cannot be maintained stable. The purpose of this study was to find out the way to optimize the stiffness of mounts via the design of experiments (DOE). According to the DOE process, a full factorial design was implemented. The z-direction stiffness of three mount blocks in the mounting system was selected as the three analysis factors. The maximum and the minimum stiffness of each mount block within the manufacturing tolerance were selected as the two levels. The measured vibration of vehicle body under certain loading case was selected as the response factor. After eight times of experiment, the DOE parameters were analyzed with statistical methods. The final DOE results showed that the vibration of vehicle could be expressed by a linear equation, the parameters in which are the stiffness of mount blocks. And the analysis of variance indicated that the vibration of vehicle is mostly affected by the stiffness of engine mount block.
Wang, Yang, Xu, Yong, Tan, Xiao
Study for the Radiated Noise from Engine Depending on Assembly Condition2017-01-18436/5/2017
This paper presents the influence of radiated noise from engine surface according to assembly condition between the engine block and oil pan. At the first, the force exciting the main bearing of cylinder block is calculated by using a multi-body dynamics model of the engine crankshaft. Secondly, the modal analysis is processed to obtain the mode contribution and modal participation factors for the FEM of a virtual cylinder block. Thirdly, the radiated noise from a structure is calculated by acoustic-FEM analysis. This structure is assembled by the virtual oil pan with a rigid connection method and a soft connection method. The sandwich panel connection model is used for the soft connection method. The sound radiated from this assemble structure is calculated according to two different connection properties respectively. The sound matrices for two results are compared using an objective method. Finally, the influence of the connection condition on the sound quality is investigated for the further research in a sound quality of the sound emitted by a real engine structure in a diesel engine.
Shin, Taejin, Jin, Jaemin, Lee, Sang Kwon, Jung, Insoo
Optimization of Front Wheel Drive Engine Mounting System for Third Order Shudder Improvement2017-01-91754/11/2017
Nowadays, the vehicle design is highly ruled by the increasing customer demands and expectations. In addition to ride comfort and vehicle handling, the Noise, Vibration and Harshness (NVH) behavior of the powertrain is also a critical factor that has a big impact on the customer experience. To evaluate the powertrain NVH characteristics, the NVH error states should be studied. A typical NVH event could be decoupled into 3 parts: source, path, and receiver. Take-off shudder, which evaluates the NVH severity level during vehicle take-off, is one of the most important NVH error states. The main sources of Front Wheel Drive (FWD) take-off shudder are the plunging Constant Velocity Joints (CVJ) on the left and right half shafts. This is because a plunging CVJ generates a third order plunging force with half shaft Revolution Per Minute (RPM), which is along the slip of the plunging CVJ. The primary path of take-off shudder is the Engine Mounting System (EMS), which isolates the vibration inputs from the vehicle body. A typical receiver of shudder is the passenger seat, so seat track acceleration and velocity are usually chosen to be the design objective for vehicle NVH optimization. This paper presents the optimization of FWD engine mounts for third order shudder improvement. Pointer automatic optimizer is used to perform the optimization with respect to a large number of design variables.
Zhu, Yitao, Addepalli, Kalyan, Remisoski, Natalie, Datar, Makarand
Degradation of Vehicle Noise and Vibration by Ageing of Elastomers2017-01-03923/28/2017
The vehicle elastomeric components such as engine mounts could be aged and degraded by environmental loads such as thermal and mechanical loads during long term usage by customers. These make the degradation of vehicle driving performance comparing with a new condition. In this study, the main cause of NVH (Noise, Vibration and Harshness) degradation of a used vehicle was analyzed. It could be identified by the analysis of vibration insulating property changes of elastomeric components. The properties changes of aged engine mounts were analyzed and compared with initial properties. The accelerated laboratory ageing test mode was developed for simulating the degradation of engine mounts by thermal load analysis. Moreover, parametric studies were carried out to identify the robust engineering design technique. The engineering design parameters of elastomers such as volume, thickness and mechanical loading types were identified to improve the degradation phenomenon.
Sung, Dae-Un, Busfield, James, Ryu, Yong Hyun
Mount Model Dependent on Amplitude and Frequency for Automotive Powertrain Mounting System2017-01-04053/28/2017
Three constitutive models which capture the amplitude and frequency dependency of filled elastomers are implemented for the conventional engine mounts of automotive powertrain mounting system (PMS). Firstly, a multibody dynamic model of a light duty truck is proposed, which includes 6 degrees of freedom (DOFs) for the PMS. Secondly, Three constitutive models for filled elastomers are implemented for the engine mounts of the PMS, including: (1) Model 1: Kelvin-Voigt model; (2) Model 2: Fractional derivative Kelvin-Voigt model combined with Berg’s friction; (3) Model 3: Generalized elastic viscoelastic elastoplastic model. The nonlinear behaviors of dynamic stiffness and damping of the mounts are investigated. Thirdly, simulations of engine vibration dynamics are presented and compared with these models and the differences between common Kelvin-Voigt model and other constitutive models are observed and analyzed.
Lv, Tianqi, Feng, Xingxing, Xu, Peijun, Zhang, Yunqing
An Improved PID Controller Based on Particle Swarm Optimization for Active Control Engine Mount2017-01-10563/28/2017
Manufacturers have been encouraged to accommodate advanced downsizing technologies such as the Variable Displacement Engine (VDE) to satisfy commercial demands of comfort and stringent fuel economy. Particularly, Active control engine mounts (ACMs) notably contribute to ensuring superior effectiveness in vibration attenuation. This paper incorporates a PID controller into the active control engine mount system to attenuate the transmitted force to the body. Furthermore, integrated time absolute error (ITAE) of the transmitted force is introduced to serve as the control goal for searching better PID parameters. Then the particle swarm optimization (PSO) algorithm is adopted for the first time to optimize the PID parameters in the ACM system. Simulation results are presented for searching optimal PID parameters. In the end, experimental validation is conducted to verify the optimized PID controller. The study demonstrates that the improved PID controller reveals effective vibration isolation performance.
Guo, Rong, Wei, Xiao-Kang, Gao, Jun
A Method of Acceleration Order Extraction for Active Engine Mount2017-01-10593/28/2017
The active engine mount (AEM) is developed in automotive industry to improve overall NVH performance. The AEM is designed to reduce major-order signals of engine vibration over a broad frequency range, therefore it is of vital importance to extract major-order signals from vibration before the actuator of the AEM works. This work focuses on a method of real-time extraction of the major-order acceleration signals at the passive side of the AEM. Firstly, the transient engine speed is tracked and calculated, from which the FFT method with a constant sampling rate is used to identify the time-related frequencies as the fundamental frequencies. Then the major-order signals in frequency domain are computed according to the certain multiple relation of the fundamental frequencies. After that, the major-order signals can be reconstructed in time domain, which are proved accurate through offline simulation, compared with the given signals. To verify the real-time performance of the method, a hardware-in-the-loop testing system based on MATLAB xPC target is established. LMS Data Acquisition System is adopted to track rotating speed online and extract major-order signals offline, the results of which are considered as the comparison with the online results from the hardware-in-the-loop testing system. It can be found that the method features high accuracy in extracting order information online with a reduced computational burden, therefore it satisfies the requirement of the real-time control of the AEM.
Guo, Rong, Gao, Jun, Wei, Xiao-kang
Development of a Virtual Multi-Axial Simulation Table to Enhance the Prognosis of Loads on Powertrain Mounting System During Durability Applications2017-01-04203/28/2017
Vibration Isolation is the key objective of engine mounting systems in the automotive industry. A well-designed, robust engine mount must be capable of isolating the engine assembly from road-based excitations. Owing to high vibration inputs, engine mounts are susceptible to wear and failure. Thus, the durability of engine mounts is a cause for concern. A design validation methodology has been developed at Jaguar Land Rover using Multibody Dynamics (MBD) to enhance the prognosis of engine mount loads during full - vehicle durability test events. This paper describes the development of a virtual multi-axial simulation table rig (MAST Rig) to test virtual engine mount designs. For the particular example considered in this paper, a simple sinusoidal input is applied to the MAST Rig. The development of the virtual MAST Rig has been described including details of the modelling methodology. In order to demonstrate the potential of the virtual test, correlation was carried out with tests conducted on a physical MAST Rig, and the achieved results have been presented. The approach described here can be applied to test the designs of engine mounts for durability applications at early stages of the development process. The results have shown great correlation at lower frequencies. At higher frequencies, though the engine resonance is shown by the virtual test, the phenomenon is not identical in the frequency domain. These results have identified areas of improvement in mount design, and have led to better prognosis of engine mount loads, owing to close collaboration with the design team.
Khapane, Prashant, Lohani, Sumiran
Thermal Protection of Rear Mounted Engine and Its Components Using a Ventilation Fan with Unique Monitoring and Fault Diagnosis Technique2017-01-06203/28/2017
The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates. The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan. With the implementation of additional ventilation fan it is observed that maximum engine compartment temperature does not exceed safe operating temperature limit when the vehicle is driven in all road load condition (including highway, city & gradient drive conditions) and in all vehicle operating conditions. Excessive operation at higher compartment temperature unnecessarily causes individual component durability & performance to deteriorate at considerably faster rate. Thus, method of the present disclosure ensures that every component in engine compartment is operating in safe operating limits. In-case any failure occurs in the ventilation fan, newly developed EMS diagnosis strategy identify fault and indicates the problem to the driver through telltale. EMS also restricts the vehicle speed to safely maneuver vehicle to the nearest service center for repair.
Parmar, Chandrakant, Tyagarajan, Sethuramalingam, Tiwari, Sashikant, Thonge, Ravindra, Paul, S Arun
Injection Pattern Design for Real Time Control of Diesel Engine Acoustic Emission2017-01-05963/28/2017
Upcoming more stringent emission regulations throughout the world pose a real challenge, especially in regard to Diesel systems for passenger cars, where the need of additional after-treatment has a big impact in terms of additional system costs and available packaging space. Therefore, the need for strategies that allow managing combustion towards lower emissions, that require a precise control of the combustion outputs, is definitely increasing. Acoustic emission of internal combustion engines contains a large amount of information related to engine behavior and working conditions. Mechanical noise and combustion noise are usually the main contributions to the noise produced by an engine. In particular, recent research from the same authors of this paper demonstrated that combustion noise can be used as an indicator of the combustion that is taking place inside the combustion chamber and therefore as a reference for the control strategy. Previous works showed the correlations existing between in cylinder combustion and the acoustic emission radiated by the engine, and presented a possible approach to use this signal in the engine management system for control purposes. In this work, additional experiments were carried out, in order to further investigate how to design the optimal injection pattern. The application was tested by running several experimental tests, in steady state conditions, on a Diesel engine mounted in a test cell. Tests have been run in order to identify the correlation existing between the different injection/combustion patterns that can be operated on the engine and the corresponding acoustic emission, to be used in the closed- loop combustion control based on engine noise feedback.
Ravaglioli, Vittorio, Stola, Federico, De Cesare, Matteo, Ponti, Fabrizio, Sgatti, Stefano
Multibody Dynamics Cosimulation for Vehicle NVH Response Predictions2017-01-10543/28/2017
At various milestones during a vehicle’s development program, different CAE models are created to assess NVH error states of concern. Moreover, these CAE models may be developed in different commercial CAE software packages, each one with its own unique advantages and strengths. Fortunately, due to the wide spread acceptance that the Functional Mock-up Interface (FMI) standard gained in the CAE community over the past few years, many commercial CAE software now support cosimulation in one form or the other. Cosimulation allows performing multi-domain/multi-resolution simulations of the vehicle, thereby combining the advantages of various modeling techniques and software. In this paper, we explore cosimulation of full 3D vehicle model developed in MSC ADAMS with 1D driveline model developed in LMS AMESim. The target application of this work is investigation of vehicle NVH error states associated with both hybridized and non-hybridized powertrains. AMESim is responsible for generating the engine excitation, dampers, and detailed transmission, along with modeling the control strategy for powertrain component operations. Engine block, engine mounts, driveshaft, differential-axle unit, suspension, half-shafts, wheels, and body are modeled in ADAMS and imported as a functional mock-up unit in AMESim. Several key steady-state and transient error states are investigated. In particular, we look at the vibration response at the customer touch points due to transient phenomena generated by engine. Although a specific application of cosimulation is demonstrated in this paper, the methodology is general and can be used to simulate any powertrain system – vehicle combination. Hence data transfer between the co-simulating software is described and effects of key parameters, such as integrator type, time steps, and communication interval, on the quality of results are also investigated.
Khan, Imad M., Datar, Makrand, Sun, Wulong, Festag, Georg, Juang, T Bin, Remisoski, Natalie
Design Optimization of Engine Mounts for Commercial Vehicle Application to Avoid Failures2017-26-02871/10/2017
The Mounting system of component plays a major role in determining the structural durability, compatibility and synchronization of the systems with respect to each other. The major function of Engine mounts is to isolate the engine from the chassis and to align the power-train system of vehicle according to needs. Here we exclusively deal with the failure case of a Heavy duty commercial vehicle Engine Mounts and its optimization. We do formulate a theoretical calculation for the estimation of engine loads, Center of Gravity (C.G) and characteristics of existing engine mount followed by a failure root cause analysis based on design and transmissibility parameters. This is then correlated with data from Computed Aided Engineering and Matlab for analysis of the existing model which is compared to the experimental transmissibility from Road load data Acquisition (RLDA). This is to validate the conditions and propose optimizations to reduce critical failures.
Kurna, Srinivas, Jain, Rahul, Mathur, Arpit, Parwal, Mahendra, Legala, Adithya
Split Type Crankcase Design for a Single Cylinder LCV Diesel Engine2017-26-00401/10/2017
Serious efforts have been put in space to focus on lowering the fuel consumption and CO2 discharge to the environment from Automotive Diesel Engines. Though more focus is put on material up gradation approach on weight perspective, it is accompanied by undesirable cost increase and manufacturing complexity. As a part of development of a single cylinder engine for a light commercial vehicle application, a unique approach of integrated split type crankcase design is designed and developed. This design have addressed all the key factors on Weight, Cost and Manufacturing perspectives. The split type crankcase configuration, particularly middle-split configuration, integrates the oil sump, front cover and flywheel housing in a single unit beneficial from the point of view of reducing engine weight and thus reducing the manufacturing costs. This crankcase is also excellent from the serviceability point of view. Further, due to less number of sealing joints, this configuration obviates oil leakages prevalent in the existing crankcases. The ribbing pattern internally and externally provided on the crankcase helps in achieving better NVH characteristics and also offers a simple load transfer path. The paper further portrays the complete perspective and design methodology used during design process. Integration of classical methods, and FE analysis is presented. Simulation results are elaborated to show the effectiveness of an integrated approach used in this development program Tools like DFMEA, DFMA etc are used along with value engineering concepts to make an efficient and cost effective product to the end customer with minimum iterations in reduced cycle time.
Dharan R, Bharani, Vikraman, V, Varghese, Joy, Bhattacharya, Anup, Yadav, Vivek
Method for Optimizing Scooter Engine Mounts Position for Reduced Vibration2016-32-004211/8/2016
Vibrations have become an increasingly important attribute for determining the quality of automotive products. Particularly, this becomes more acute in the case of tactile vibrations of powered two-wheelers - motorcycles and scooters. This paper deals with vibrations of a scooter vehicle. Scooters are normally a two-wheeler with a four stroke single cylinder spark ignited engine. Vibrations of a scooter are mainly caused by the inertial imbalance forces of the engine, combustion forces and road undulations. Vibrations due to road undulations are mostly reduced by toggle link mechanism, resilient mounts of the engine and the shock absorbing suspension of the frame. The power train assembly is designed in such a way that the inertial imbalance forces in the power train assembly are distributed at a required angle called the ellipse angle. This configuration ensures that the engine forces which are spread unequally in different directions are made to align and contribute only to the vertical and pitch modes of the engine. In spite of the achieving the above mentioned configuration, there are vibrations due to force transfer through the toggle link mechanism to the vehicle frame. This paper explains ways of reducing of tactile vibration of a scooter by addressing these issues by using the theory of center of percussion. It also explains ways of determining the optimum mounting position of a scooter engine based on engine layout, engine geometry, inertial balancing of engine forces, isolation and the center of percussion for reduced vibration. Theoretical analysis with calculations about the angle of engine mounting, length of the swing arm, aligning engine forces by distributing the imbalance mass are discussed. Analytical models are then validated using experiments on design optimized configuration resulting in increased vibration comfort of the vehicle.
Rajagopal Jeyapaal, Bhaarath, Krishna, Vamsi, Marudachalam, Kannan
Effect of Three Controls (Camber Angle Control, Derivative Steering Assistance Control, and Inside-Outside Wheel Braking Force and Driving Force Control in Body Slip Angle Area2016-01-16664/5/2016
In this research, we examine the three controls inside-outside wheel braking force and driving force, camber angle, and the derivative steering assistance to determine how angle differences affect cornering performance and controllability. This is accomplished by comparing body slip angle area differences in a closed loop examination of the grip to drift area using a driving simulator. The results show that inside-outside wheel braking force and driving force control in the area just before critical cornering occurs has a significant effect on vehicle stability. We also clarified that controlling the camber angle enhances grip-cornering force, and confirmed that the sideslip limit could be improved in the vicinity of the critical cornering area. Additionally, when the counter steer response was improved by the use of derivative steering assistance control in the drift area exceeding the critical cornering limit, corrective steering became easier. Moreover, the effect could be achieved by using camber angle and derivative steering assistance controls in combination over a wide area. Based on the above, we conclude that it is possible to control wide-ranging body slip angle areas by combining the three abovementioned controls.
Yamaguchi, Ryo, Nozaki, Hiromichi
Powertrain Motion Control Analysis under Quasi-Static Extreme Loads2016-01-04394/5/2016
The powertrain mounting system (PMS) plays an important role in improving the NVH (Noise, Vibration, Harshness) quality of the vehicle. In all running conditions of a vehicle, the displacements of the powertrain C.G. should be controlled in a prescribed range to avoid interference with other components in the vehicle. The conventional model of PMS is based on vibration theory, considering the rotation angles are small, ignoring the sequence of the rotations. However, the motion of PMS is in 3D space with 3 translational degrees of freedom and 3 rotational degrees of freedom, when the rotation angles are not small, the conventional model of PMS will cause errors. The errors are likely to make powertrain interfering with other components. This paper proposes a rigid body mechanics model of the powertrain mounting system. When the powertrain undergoes a large rotational motion, the rigid body mechanics model can provide more accurate calculation results. The quasi-static equation for solving displacements of the powertrain C.G. is presented, and the Newton-Raphson iterative algorithm is developed to obtain the displacements of the powertrain C.G.. The methods for estimating the displacements of the powertrain C.G. and the reaction forces of the mounts are also proposed. With the transverse powertrain of a vehicle as example, two models are presented for comparing: one is the vibration model, another one is the rigid body mechanics model, and the displacements and reaction forces on the mounts under typical and extreme load cases are calculated respectively. The results show that in extreme load cases, the rigid body mechanics model can be calculated more accurately than the vibration model. The displacements can provide a prescribed range to avoid interference with other components in the vehicle. The reaction forces can be used as input loads for the design and fatigue test of mounts.
Lv, Tianqi, Xu, Peijun, Zhang, Yunqing
Development of New 3.5 L V6 Turbocharged Gasoline Direct Injection Engine2016-01-10124/5/2016
This paper introduces the newly developed super sports car engine mounted in the new model NSX. A super sports car engine was newly developed to satisfy the high power performance required by the body package. Higher power and compactness were simultaneously achieved by selecting an engine displacement of 3.5 L and by using a V6 layout and a turbocharger. This enabled to mount a power train that combines a hybrid motor with a newly developed transmission in the rear of the body. The lubrication system uses a dry sump system capable of maintaining reliable lubrication in all possible super sports car driving scenarios. The combustion system uses high tumble-flow ports, a direct injection and a port injection system that increase power performance and thermal efficiency, emission reduction. To support the increased heat load due to higher power, a 3-piece water jacket is used around the combustion chamber and the exhaust ports. This optimized the cooling water flow to each part of the cylinder head, enabling to simultaneously suppress knock and cool the exhaust ports. The cylinder bores have a Fe spray coating that enabled a reduction in weight while enhancing cooling. This spray-coated liner can form a film that is both harder and thinner than typical steel liners and aluminum liners. This suppressed the increase in the bore pitch, and allowed positioning of cooling water channels between the bores.
Furumata, Seiji, Kakinuma, Takashi, Tochiki, Hirokazu
Engine Acoustic Emission Used as a Control Input: Applications to Diesel Engines2016-01-06134/5/2016
The need for strategies that allow managing combustion in an adaptive way has recently widely increased. Especially Diesel engines aimed for clean combustion require a precise control of the combustion outputs. Acoustic emission of internal combustion engines contains a lot of information related to engine behavior and working conditions. Mechanical noise and combustion noise are usually the main contributions to the noise produced by an engine. Combustion noise in particular can be used as an indicator of the combustion that is taking place inside the combustion chamber and therefore as a reference for the control strategy. This work discusses the correlations existing between in cylinder combustion and the acoustic emission radiated by the engine and presents a possible approach to use this signal in the engine management system for control purposes. The application was tested by running several experimental tests, both in steady state and transient conditions, on a Diesel engine mounted in a test cell. Tests have been run in order to first identify the correlation existing between the different injection/combustion patterns that can be operated on the engine and the corresponding acoustic emission. Once the correlation between combustion process and engine noise has been identified it can be used to set up a closed-loop algorithm for optimal combustion control based on engine noise prediction.
Ponti, Fabrizio, Ravaglioli, Vittorio, Stola, Federico, De Cesare, Matteo
Virtual Drivetrain Simulation Using Adams View and Correlation with Test2016-01-13614/5/2016
Reducing the vibrations in the drivetrain is one of the prime necessities in today’s automobiles from NVH and strength perspectives. The virtual drivetrain simulation methodology to predict the driveline induced excitations transmitted to vehicle is developed for three cylinder engine using Adams View. The obtained mount forces from Adams dynamic simulation is correlated with the measured test data at vehicle level and the good correlation is observed. Paper discusses on the methodology of virtual drivetrain using Adams view and the correlation of measured dynamic mount forces with simulation results. This correlation gives the confidence that the developed simulation methodology can be used to get the mount forces of different orders from drivetrain.
Londhe, Abhijit, Yadav, Vivek, Kannaiyan, SenthilKumar, Karthikeyan, Krishnan, Reddy, Ganeshan
Application Study of Nonlinear Viscoelastic Constitutive Model for Dynamic Behavior of Suspension Arm Bushing2016-01-13754/5/2016
Ride quality is an important purchasing consideration for consumers. It is typically defined in terms of noise, vibration and harshness. These phenomena are a result of vibrations caused at the engine/powertrain and from the road surface, which are transmitted to the passenger cabin. To minimize such vibrations, rubber parts are used extensively at mounting points for the cabin, such as engine mountings and suspension bushings. The vehicle development process increasingly requires performance testing, including rubber parts using CAE, prior to prototype evaluation. This in turn requires a rubber material model that can accurately describe dynamic characteristics of rubber components, particularly frequency and amplitude dependency. Conventional rubber models using commercially available structural analysis solvers cannot solve for both frequency and amplitude dependency at the same time, and are unable to predict transient phenomena such as harshness that involve inputs of varying amplitude. The authors have proposed a new rubber material model that is able to reproduce both frequency and amplitude dependency simultaneously, based on the rubber material model developed by Simo, J.C. [1]. Previous studies have demonstrated the accuracy of the new model under quasi-static and harmonic input conditions. Actual vehicle evaluation involves several input directions, with simultaneous translational and rotational inputs that are transient. In this paper, the new rubber material model is applied to a suspension arm bushing to confirm bushing force when subjected to complex inputs. The model was shown to predict bushing stiffness with greater accuracy and therefore was validated.
Ueda, Masahiro, Ito, Satoshi, Suzuki, Daichi
Balancing Optimization of a Motorcycle Engine Crankshaft for Vibration Reduction2016-01-10604/5/2016
With ride comfort in a motorcycle gaining significance, it is important to minimize vibration levels at the customer touch points. The reciprocating piston imparts rotary motion to the crankshaft which in turn induces unbalance forces and produces vibration in the vehicle, thus influencing the ride quality. Generally, the primary inertial forces are balanced by a combination of balancer body and crank web. However, being a commuter bike, a balancer body could not be accommodated due to cost and space constraints. In such scenario, the first order unbalance force cannot be completely eliminated but can only be redistributed by adding counterweight to the crankshaft. Proper distribution of these forces is required for optimum vibration levels at motorcycle touch sensitive points (TSP) such as handle bar, footrest etc. In the current study, crankshaft of a single cylinder motorcycle engine is optimized for balancing to reduce vibration at the TSP through multi body dynamics (MBD) and finite element (FE) simulation tools. The complete crank train comprising of piston assembly, connecting rod, bearing, crankpin and crankshafts are modelled with accurate mass and inertia in a commercially available MBD software. Crankshaft balancing factor and the angle of unbalance force are varied by changing different design parameters of the crankshaft such as web radius and width, modification in shape etc. Inertia forces at engine mounting locations due to the first order unbalance of crankshaft are predicted using MBD simulation. These forces are then given as input to full vehicle FE model to predict the vibration response at TSP for the operating speed range of vehicle. Crankshaft design is finalized based on optimal vibration response at TSP.
Ganguly, Arnab, Bhatia, Niket, Agarwal, Vikas Kumar, Mohite, Ulhas
Vehicle Driveability: Dynamic Analysis of Powertrain System Components2016-01-11244/5/2016
The term driveability describes the driver's complex subjective perception of the interactions with the vehicle. One of them is associated to longitudinal acceleration aspects. A relevant contribution to the driveability optimization process is, nowadays, realized by means of track tests during which a considerable amount of driveline parameters are tuned in order to obtain a good compromise of longitudinal acceleration response. Unfortunately, this process is carried out at a development stage when a design iteration becomes too expensive. In addition, the actual trend of downsizing and supercharging the engines leads to higher vibrations that are transmitted to the vehicle. A large effort is therefore dedicated to develop, test and implement ignition strategies addressed to minimize the torque irregularities. Such strategies could penalize the engine maximum performance, efficiency and emissions. The introduction of the dual mass flywheel is beneficial to this end. Nevertheless, its role on the vehicle driveability, as well as that of other driveline components, is not yet so clear. The aim of the present work is to establish which are the main driveline components affecting the filtering behavior of the transmission and how their parameters can be tuned in order to improve the vehicle ability to respond to driver’s different demands without negative impact on his comfort. A complete nonlinear coupled torsional and longitudinal vehicle dynamic model is proposed to this end. The model is validated both in time and frequency domain and allows linearization of its nonlinear components.
Castellazzi, Luca, Tonoli, Andrea, Amati, Nicola, Piu, Alessandro, Galliera, Enrico
Custom Design Multi-Axial Engine Mount Load-Cell Development for Road Load Identification and Fatigue Life Estimation2016-01-04134/5/2016
Internal combustion engines are attached on the vehicle body using engine mounts composed of two cast iron brackets and a rubber isolator connecting them. Engine mount road load identification during vehicle durability tests on proving ground is a critical task for engine mount development. Using standard multi-axial load-cell is not possible unless major design revisions on the vehicle body or engine block are done. Using wheel force transducers and vehicle dynamic simulation tools need extensive model tuning work to get accurate load information. Hence, a custom multi-axial load-cell design is preferred for the engine mount load identification of a BCar I4 engine. The developed load-cell engine mount bracket can be installed without doing any design changes on the vehicle. Design, durability analysis, instrumentation, calibration and vehicle installation of custom designed six degree of freedom multi-axial load cell have been performed. Strain and acceleration measurements have been conducted on vehicle durability test track. Data have been processed to obtain forces and moments in six degree of freedom on the engine mounts. The loading information was used for fatigue life estimation.
Ozturk, Umud Esat, Ucar, Lutfi, Shahidi, Kaveh, Ersoy, Nuri, Zobi, Onur, Bagdat, Umit, Yanarocak, Rıfat, Elmalı, Serkan
Review and Assessment of Frequency-Based Fatigue Damage Models2016-01-03694/5/2016
Several popular frequency-based fatigue damage models (Wirsching and Light, Ortiz and Chen, Larsen and Lutes, Benascuitti and Tovo, Benascuitti and Tovo with α.75, Dirlik, Zhao and Baker, and Lalanne) are reviewed and assessed. Seventy power spectrum densities with varied amplitude, shape, and irregularity factors from Dirlik’s dissertation are used to study the accuracies of these methods. Recommendations on how to set up the inverse fast Fourier transform to synthesize load data and obtain accurate rainflow cycle counts are given. Since Dirlik’s method is the most commonly used one in industry, a comprehensive investigation of parameter setups for Dirlik’s method is presented. The mean error and standard deviation of the error between the frequency-based model and the rainflow cycle counting method was computed for fatigue slope exponent m ranging from 3 to 12. The results showed Ortiz and Chen, Benascuitti and Tovo with α .75, Larsen and Lutes, Dirlik, and Benascuitti and Tovo to be significantly more accurate than Lalanne and Zhao and Baker. These five models have a tendency for the error variation to increase as the fatigue exponent m increases. For this study using Dirlik’s seventy spectra, Ortiz and Chen, Benascuitti and Tovo with α .75, and Larsen and Lutes Single Moment methods had lower mean error than Dirlik’s method.
Quigley, John P., Lee, Yung-Li, Wang, Liang
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