Browse Topic: Springs

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Achieving ride comfort in bus suspension by varying air spring performance2026-26-00811/16/2026
Air springs are widely used in commercial buses to obtain better quality of ride and comfort. Selecting the right air spring is a critical aspect of suspension design. However, this selection process is often constrained by the limited availability of off-the-shelf components as the development of a custom air spring involves long lead time and high tooling cost. This can be justifiable only at high production volumes. Air springs are tunable as compared to conventional mechanical metal springs. Their performance can be adjusted by varying the internal air pressure and volume, enabling them to accommodate a wide range of vehicle load conditions. In actual design practice, component packaging constraints and fixed mounting dimensions often restrict the choice of air spring. Additionally, Front and rear suspension requires air springs with different characteristics. To overcome these limitations, an auxiliary air tank is also called a ping tank that can be used along with an existing
Patre, Kamlesh, Salunkhe, Swapnil, Paranjape, Shekhar
Systematic Study To Understand And Resolve Brake Pull In Commercial Vehicles Using Simulation And Proving Ground Tests2026-26-00831/16/2026
In traditional commercial vehicles with leaf spring suspension and Recirculating Ball Joint (RCBT) steering systems often experience undesirable pulling due to unsymmetrical steering mechanism during braking, especially when the suspension and steering hardpoints are not properly tuned. This study investigates the causes behind such pulling behavior, specifically focusing on brake steer and bump steer, which occur due to misalignments in the suspension and steering geometries. Brake steer happens when the braking forces generate a torque, causing the vehicle to pull towards one side. On the other hand, bump steer refers to the unwanted changes in the wheel alignment when the suspension undergoes travel, leading to instability or unintended steering input. These two phenomena, if not controlled, can result in undesirable vehicle handling, especially under heavy braking conditions. The study aims to understand and quantify these mechanisms, providing insights into how they can be
Pandhare, Vinay Ramakant, M, Anantha Padmnabhan, NIZAMPATNAM, BALARAMAKRISHNA, Londhe, Abhijit, Doundkar, Vikas
Failure Analysis of Dissimilar Metal Weld Joint of an Air Spring Bracket within an Automotive Active Seat Suspension System2026-26-04871/16/2026
In modern four-wheelers, seat suspension systems play a crucial role in enhancing occupant comfort by mitigating the effects of road unevenness and vibrations. Among these systems, active suspension mechanisms offer advanced performance through complex assemblies involving welded, riveted, and bolted joints. This study investigates the failure of an air spring bracket - a critical component of a pneumatic active suspension system - manufactured by Gas Metal Arc Welding (GMAW) of two dissimilar ferrous materials which are likely to be SAPH440 and S355J2. These different materials were used based on mechanical properties required to perform by their particular part. System level validation tests were conducted to ensure the reliability of the seat suspension system. The one of the validation tests is continuous cyclic fatigue test which is carried out on the complete seat assembly. However, during vibration / cyclic endurance testing, premature failures were observed near the weld joints
Patale Jr, Reshma, PINJARI, JAYANT NAMDEV, BALI, SHIRISH
Data-Driven Prediction of Damper durability Cycles Using AIML Techniques2026-26-05501/16/2026
The suspension dampers play a pivotal role in controlling suspension dynamics, especially during rapid suspension movements such as pothole impacts, speed bumps, and off-road conditions. The dampers directly influence the ride comfort, vehicle stability. Ensuring the durability of these valves is essential to maintain consistent performance throughout the vehicle's lifecycle. To validate the valve configuration at high speed, in current development practices, durability cycles are typically derived through physical data collection on actual vehicle driven on proven ground tracks. While this method provides accurate real world validation, it is highly time consuming and resource intensive. The dependency on full vehicle testing also limits early phase of validation, creating bottlenecks in the product development cycle. An AIML based methodology is presented in this paper to predict the HSVD cycles for damper validation. The AIML algorithm was trained using the historical test data and
Kabbin, Chetan D., Suryawanshi, Vishal, Daphal, Pratap, Kulkarni, Prasad
Test Methodology Development For Rig Level Validation Of Light Weight Stabilizer Link Of EV Bus Suspension2024-26-03571/16/2024
In the modern and fast growing automotive sector, reliability & durability are two terms of utmost importance along with weight ad cost optimization. Therefore it is important to explore new technology which has less weight, low manufacturing cost and better strength. The new technology developed always seek for a quick, cost effective and reliable methodology for its design validation so that any modification can be made by identifying the failures. This paper presents the rig level test methodology to validate and to correlate the CAE derived strain levels, life cycle & failure mode of newly developed light weight stabilizer link for EV Bus suspension. Stabilizer link replaces the existing separate arrangement of anti-roll bar and parallel rods and light in weight by 30kg.This stabilizer link arrangement is having the short lever arms which are connected through torsion bar which goes under twisting moment and the short lever arms are intended to control wheel motion in longitudinal
Tangade, Atul Bandu, Babar, Sunil, Bankar, Milind Achyutrao, Mehendale, Ravindra, Dhumal, Kailas, Bhusari, Deepak
A comparative study of vehicle handling characteristics of commercial vehicle with innovative nonlinear stiffness mono-leaf suspension with parabolic spring suspension through simulation2024-26-00571/16/2024
In recent years due to significant increased cost of raw material, fuel and energy, vehicle cost is increased. As vehicle cost is one of the major factors that attracts prospective buyers, it has created specific demand for low weight and low-cost components than traditional components with better performance to meet customer expectations. Suspension is one of the critical aggregates where lot of material is used and reduction in weight tends to give lot of cost benefit. As suspension system derives vehicle's handling performance, it has to be ensured that handling performance of vehicle is maintained the same or made better while reducing weight of the suspension. Advancements in simulation capabilities coupled with manufacturing technology has enabled development non-traditional leaf springs. One of such springs is mono-leaf spring without. This type of leaf spring provides advantages such as low weight and nonlinear stiffness. Hence, this type of spring can cater the need of soft
Pandhare, Vinay Ramakant, Tiwari, Chaitanya, Deore, Yogesh, Khandekar, Dhiraj
Comparative study of bending loads on rear axles of heavy commercial vehicles for two different real leaf spring configurations2024-26-03741/16/2024
In commercial vehicles, leaf springs play a major role in designing the suspension system. Leaf springs are the mostpopular designs having multiple leaves in contact with each other and show hysteresis behavior when loaded and unloaded. The leaf spring acts as a linkage for holding the axle in position and thus separate linkages are not necessary. It makes the construction of the suspension simple and strong. Because the positioning of the axle is carried out by the leaf springs, it is disadvantageous to use soft springs i.e. springs with low spring constant. Leaf springs are excellent in suspending large loads, since they are designed using 'bending beam' equations. The stiffness of the leaf spring assembly can be altered as desired, by changing the number of leaves. The objective of this paper is to compare the bending loads coming at the rear wheel centers of the vehicle when it runs in torture track and over a single bump. Bending loads were compared for the same rear suspension
Korrayi, Rajesh, Dixit, Vishnu
Accelerated Lab Test facility for NRS Leaf Spring bracket for HCV Application2024-26-03441/16/2024
In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper tails on developing an accelerated lab test methodology for NRS leaf spring bracket by simulating field failure. Initially, potential failure causes for spring bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the damage on the spring bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle. Field failure was simulated with the existing design samples and Improved design of spring bracket was validated in the same test conditions and compared with the life of existing
G, Manthiramoorthy
Analysis and Annihilation of Grunt Noise in Hydraulic Power Assisted Steering Systems2024-26-02181/16/2024
Hydraulic steering systems employ pressurized fluid to alleviate the effort needed to steer the wheels of an automobile. Hydraulic Power Assisted Systems (HPAS) are cost-efficient, yet intricate. As customer trends lean towards reduced effort and improved handling, HPAS must intervene more in steering, leading to increased pressure requirements from the HPAS pump. Consequently, HPAS components must withstand higher pressure liquid and operate with closer tolerances, occasionally resulting in anomalous functioning. This paper delves into one anomaly with HPAS systems "Grunt Noise", a phenomenon caused by the resonance of the Torsion bar (T-bar) with fluid pressure pulsations. An extensive study was conducted to identify load conditions for grunt noise generation, examine transfer paths and analyze its frequency band. The study also explored the cascading process, reproducing the vehicle-level phenomenon at the rig-level for the Rack and Pinion and later at Pinion Valve assembly level
SETHI, AJITESH, Titave, Uttam, Vardhanan K, Aravindha Vishnu, Zalaki, Nitin, Naidu, Sudhakara
Experimental Characterization of a Steel Spring Mount using Virtual Point Transformation2025-01-00465/5/2023
The application of virtual point transformation for determining the transfer dynamic stiffness of a steel spring mount is demonstrated in this experimental study. Rigid fixtures are attached to both ends of the spring, and frequency response functions are measured using impact hammer excitation. These measured frequency response functions are transformed to the virtual points, analogous to nodes in finite element analysis, with six degrees of freedom. This allows for high-quality frequency response functions to be obtained through specialized post-processing techniques. The six degrees of freedom transfer dynamic stiffness is then extracted using the inverse sub-structuring method, which eliminates the influence of the fixture dynamics. The results are validated by a direct measurement approach. Additionally, the study investigates the effects of liquid sprayed damping material coatings on the spring's transfer dynamic stiffness, revealing that certain damping materials significantly
Neihguk, David, Herrin, David, de Klerk PhD, Dennis
Road noise analysis using Component TPA and FBS with vehicle component modifications2025-01-00555/5/2023
Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and mount bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this
Kim, Jungu, Reichart, Ron, de Klerk, Dennis, Schütler, Willem, Malic, Mario, Kim, Hyeongjun, Kim, Uije
Application of blocked force methodology to an electrified beam axle from a medium-duty truck in vehicle and in a dynamometer test cell2025-01-00545/5/2023
The recent shift in propulsion choice away from internal combustion engines has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and sometimes multiple reduction gearsets. They also require different metrics from electric drive units because they have stiff suspension connections and lack significant isolation. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle from a battery electric medium
Shaw, Matthew D, Grimmer, Michael J
Modeling of Air Spring Dynamical Characteristics using Fractional Derivative Model and Thermal Hysteresis2025-01-00455/5/2023
Air springs are one of the most common used groups of vibration isolators and their dynamical characteristics are extensively studied. One of the main challenges of modeling of air spring dynamical characteristics is to model for hysteresis characteristics of air spring. Hysteresis characteristics of air spring are contributed by friction and viscosity of rubber bellow and by thermal hysteresis of compressed air inside air spring. In this paper, dynamic behaviors of air spring are modeled and analyzed. Firstly, force versus displacement data are obtained by the tests under static, harmonic and random excitations. Secondly, a nonlinear model is presented to capture the measured air spring’s behaviors. The model is consisted of Berg’s friction and fractional derivative model to describe rubber bellow behaviors and heat exchange model to describe thermal hysteresis of air. Furthermore, the proposed model parameters are identified using finite element model and test data. Finally, the air
Xia, Zhao
Analysis of Subharmonic Torsional Resonance in Powertrains with Two-Stage Spring Isolators2025-01-00965/5/2023
A vehicle powertrain system with a two-stage spring isolator separating a combustion engine from a transmission can exhibit significant nonlinear dynamics if the input torques cause the spring to continuously alternate between its first-stage and second-stage stiffnesses. In particular, this nonlinearity can result in subharmonic resonance of the system’s torsional natural frequencies at half the frequency of the engine’s primary excitation order. A 1D torsional vibration model was prepared using Siemens’s Simcenter Amesim software to study these nonlinear vibrations. First, a correlated vehicle-level model was developed to replicate a half-order torsional resonance that was measured in a vehicle test. Then, simplified models were used to study the sensitivity of this kind of subharmonic resonant response to changes in mean input torque level, amplitude of input torque oscillation, first-stage capacity of the spring isolator, and other factors.
Villiger, Jacob
A Study on Luxury Captain Seat Vibration in MPV Vehicles with Semi-active Suspension2025-01-01075/5/2023
More and more captain-seat-like, luxury individual seats have been appeared inside MPV vehicles in order to meet various customer needs and improve market competitiveness. In the same time, customer complains about seat vibration also increase significantly. Thus, luxury captain seat vibration is becoming MPV issues facing the vehicle development engineers. Typically, luxury captain seats are much heavier due to the added mechanisms to provide functions like massage or temperature controls, etc. and thus it is not feasible to structurally improve the seat modal frequencies to meet the traditional requirements. This paper presents a systematical study on second row luxury captain seat vibration issue between 10-25 Hz with 2 MPV vehicles. An axle contribution is analyzed with a 4-poster bench test, and the test data show that the seat vibration is more sensitivity to rear axle excitation than that of front axle, and to the out-of-phase excitation than the in-phase one. The similar
zhou, Changshui, Yu Sr, Jing, Gu, Perry, Zhang, Fan, bu, kunquan
Study of Composite Leaf Spring for Light Duty Commercial Vehicle2022-01-11579/13/2022
Study of Composite Leaf Spring for light duty commercial vehicle In the present scenario, the primary focus of automotive industry is to reduce the vehicle weight to meet future, more stringent emission norms and to improve fuel efficiency. Weight reduction becomes particularly important for commercial vehicle segment as electric vehicles are more focused on the passenger vehicle segments. Moreover, the reduction of the unsprung mass of the vehicle is desired to improve the ride and handling characteristics. Composite leaf spring is an alternative to the conventional steel leaf spring used in the suspension system of light & heavy-duty commercial vehicles. Composite leaf springs have a significantly lesser weight as compared to steel leaf springs but having higher strength to weight ratio with better corrosion resistance and hence, is considered an alternative for the steel leaf springs. This paper aims to evaluate the feasibility of replacing the steel leaf spring with a composite
Anandan, Ram, Patel, Yash, Kumar, Ankesh, Jadhav, Prashant, Shah, Shreyas
Prediction and identification of vehicle rattle noise caused by shock absorbers2022-01-03643/29/2022
A novel technology is proposed to predict vehicle rattle noise caused by shock absorbers. The model of shock absorber is developed by analyzing the force of moving parts, hydronic characteristic of valves and physical characteristic of oil. The model of mount, fixed between shock absorber and vehicle body, is developed with Maxwell method of combining series of spring and damping components. The characteristics of mount are measured under the specified frequency and amplitude conditions, the spring and damping coefficients of Maxwell model are identified using the measured data. The model of spring is developed by curve interpolation of measured data, considering the hysteresis properties of the real spring. The mass, wheel base etc. data of real vehicle are measured and the model of vehicle body is developed by Carsim using the measured data. The models of shock absorber, mount and spring are developed using Matlab/Simulink, and the vehicle body model is integrated into Simulink
Xie, Long
Enhanced SAE 3 link Leaf Spring Model to Generate Durability Virtual Loads2022-01-03403/29/2022
Heavy-duty truck vehicles are generally equipped with leaf spring suspensions. Conventionally, beam elements are used in multibody software to build the leaf spring model to calculate virtual loads. Beam elements require a high computation time due to their numerous degrees of freedoms and force components introduced by beam connections, interleaf contacts, friction, etc. Again, in these simulations, solvers frequently fail in durability loads analysis due to sudden spike in accelerations, high suspension articulation coming from severe road profiles. These drawbacks lead to the use of simplified three-link mechanism models to simulate the leaf spring’s behavior, which is computationally faster. However, the current approach is less accurate as compared to the beam element model because this model has only a torsional spring which accounts for vehicle bounce condition. In reality, the leaf spring suspension system is also subjected to cornering and braking while running on road
Dixit, Navnit, Venkatesan, Dhanasekar, Pardeshi, Ravasaheb
Simulation and Analysis of Quarter Car Model for Low Cost Suspension Test Rig2021-28-018910/1/2021
This paper deals with simulating a control system automating the operation of an existing suspension test rig at a low cost. The rig has a few limitations; it has to be operated manually, the load applied cannot be specified, and the deflection has to be measured manually. Also, a suspension setup cannot be tested for varying road profiles. The control system proposed in this paper effectively automates the process of load testing of suspension springs, at a cost relatively lower than a fully-automated test rig available in the market, while improving the breadth of its capabilities. Simulation models of both the existing test rig and modified test rig control system were plotted using SIMSCAPE. The effects of testing suspension components on both rigs were simulated, and the resulting graphs were obtained and compared.
Kumar, V Sudhir, R, Balamurugan, Thiagarajan, Raja, Deepan Kumar, Sadhasivam, R, Rinish
A Unique Methodology to Improve the Clutch Pedal Characteristics of a Compact Sports Utility vehicle2021-28-024310/1/2021
Clutch characteristics play a vital role in ensuring a smooth and comfortable customer experience of any vehicle. The expectation is to have an optimized clutch pedal effort, reduced pedal travel, adequate modulation zone and a smooth and quick pedal returnability. However, achieving all these customer requirements is extremely challenging in some cases. In the present work, the authors discuss on improving the clutch pedal characteristics of a compact sports utility vehicle (SUV by adapting a unique approach of combining a dual torsion spring (DTS) and a return spring (RS). DTS is widely used in the clutch pedal to improve the pre-load at zero travel (1.5 kg to 2.0 kg) to improve the pedal returnability in the free-play zone. Moreover, it is also quite helpful to reduce the peak pedal effort by giving a positive assistance. However, the introduction of DTS would also bring down the pedal effort (pedal holding force) at the end of the travel affecting the pedal returnability at the
Vellandi, Vikraman, Kanagaraj, Pothiraj
Optimization of Spring-Damper orientation in Double-Wishbone type Suspension geometry using Genetic Algorithm in Python2021-28-025610/1/2021
The orientation of the spring-damper system in a suspension geometry is a critical but hidden factor in vehicle performance characteristics. Spring and damper mounting characteristics are the significant factors to ensure proper contact of the tire with the ground, maintain ride height, minimize forces on spring, smooth ride, and driver comfort, as varying stiffness for spring orientation will affect the acceleration gain due to road excitation. Determining the spring orientation is conventionally a long and iterative process that involves lots of computational simulations and analytical expressions that should align with the practical vehicle constraints. Due to numerous possible orientations, the designer would randomly pick the orientation and do the simulation, which reduces the solution's reliability and the better solutions remain unexplored. This paper proposes a new methodology to optimize spring damper orientation in a suspension geometry using a genetic algorithm in Python
Madhan, Pratik, Gandhi, Om
Suitable Test Sizes for O-ring SpecificationsARP3050A (Current)9/8/2021
There are many tests that have been developed to characterize rubber O-rings. Many of these tests are independent of the size of the O-ring being tested. However, there are some tests, specifically, stress/strain properties, that are a function of the O-ring’s size. The purpose of this report is to provide guidelines for specifying O-rings that would be considered “suitable for testing” when writing O-ring material specifications.
AMS CE Elastomers Committee
Modeling and Simulation of Clutch Damper Spring Saturation Phenomenon2021-01-11048/31/2021
In modern automotive vehicles, there is a major concern for noise and vibrations generating from drivetrain. These noise and vibrations affect the passenger comfort and drivetrain parts life. Engine generates fluctuating torque and causes angular acceleration that results into torsional vibrations. These vibrations are transmitted to powertrain. Clutch disc consists damper springs and hysteresis which aids reducing these torsional vibrations. Based on the damper spring stiffness, one can control the resonance speed range and shift the resonance rpm out of driving speed range of engine. The resonance should not happen within driving speed range of vehicle to avoid large amplitude torsional vibration. But here limitation is put on the torque transmission capability of clutch for meeting vehicle requirements. As, low stiffness of damper spring requires large wind-up angle so, it is critical to decide its stiffness. The present work is related to resolving the issues of clutch damper
Mamoriya, Sandeep, Chollangi, Damodar, Jagtap, Amol
CONNECTOR, RECEPTACLE, ELECTRIC THRU BULKHEAD, WALL MOUNTING FLANGE, SERIES I (CLASS E)AS31391 (Current)6/22/2021
AE-8C1 Connectors Committee
CONNECTOR, RECEPTACLE, ELECTRIC THRU BULKHEAD, WALL MOUNTING FLANGE, SERIES I (CLASS E)AS31391-TEST-REC (Historical)6/22/2021
AE-8C1 Connectors Committee
SAE TOMORROW TODAY: The Goodyear Tire & Rubber Company Rolls Forward with the Future of Mobility130135/4/2021
Not just your grandfather's tire company, Goodyear is now shaping how people move in the future. On this episode, Erin Spring, Senior Director, New Ventures at The Goodyear Tire & Rubber Company, shares how the company is leading the way in predictive vehicle servicing to keep car and trucks safer, serviced and ready to GO!
Hineman, Marcie
SAE TOMORROW TODAY: Building Next-Gen Electric Vehicles From the Ground Up with Lucid Motors1287611/25/2020
Small but mighty. That's the future of electric vehicles. As Lucid Motors prepares to launch its first vehicle, Lucid Air, next spring, the company will also be proving that passengers don't have to sacrifice luxury, power and space for efficiency and innovation. We spoke with Eric Bach, Vice President of Hardware Engineering at Lucid Motors, to get a look "under the hood" and understand the technology that's transforming how we think about electric vehicles. Discover how Lucid Motors' competitive nature launched the company into the racing scene, how miniaturization plays a key role in Lucid Air's innovation and how customers can harness the vehicle's electric technology to power life beyond the car itself.
Hineman, Marcie
Hybrid Fuzzy-PID Control Development for a Truck Air Suspension System02-13-01-00045/11/2020
A hybrid fuzzy and proportional-integral-derivative (PID) controller is proposed for roll angle handling of a three-axle truck with an active air suspension system. The conventional truck suspension system has four air springs for the rear wheels and two leaf springs for the front wheels, which cannot properly control the pitch angle, and here in this study is upgraded into front air springs. Therefore in the full air suspension system, the pitch angle is controlled by the active suspension system. Roll reduction of a heavy vehicle can improve the ride comfort and rollover tendency of the truck, simultaneously. The relation of air spring pressures and vehicle dynamics is developed in a simple and accurate model. Using this comprehensive model, it is possible to control the variables of vehicle dynamics such as roll, pitch, and height of the truck. The truck air suspension system is examined in step steering, fishhook, and asymmetric rough road (types E and G power spectral density [PSD
Nazemian, Hossein, Masih-Tehrani, Masoud
N&V Component Structural Integration and Mounted Component Durability Implications2020-01-13964/14/2020
Exterior component integration presents competing performance challenges for balanced exterior styling, safety, ‘structural feel’ [1] and durability. Industry standard practices utilize noise and vibration mode maps and source-path-receiver [2] considerations for component mode frequency placement. This modal frequency placement has an influence on ‘structural feel’ and durability performance. Challenges have increased with additional styling content, geometric overhang from attachment points, component size and mass, and sensor modules. Base excitation at component attachment interfaces are increase due to relative positioning of the suspension and propulsion vehicle source inputs. These components might include headlamps, side mirrors, end gates, bumpers and fascia assemblies. Here, we establish basic expectations for the behavior of these systems, and ultimately consolidate existing rationales that are applied to these systems. We consider a simple two degree-of-freedom system
Stebbins, Mark, Schudt, Joseph
Spring Drive FittingTBMG-361833/1/2020
Valve and tube manufacturers continue to battle the problem of fitting pipes and tubing together quickly and reliably. The spring drive fitting addresses this challenge, bridging the gap between solutions for small-diameter tube fittings commonly seen in high-pressure, low-flow-area pneumatic systems and solutions for large flanges used in low-pressure, high-flow-area hydraulic systems.
Control Performance of Damping and Air Spring of Heavy Truck Air Suspension System with Optimal Fuzzy Control10-04-02-00132/28/2020
The air suspension system of heavy trucks not only improves the vehicle’s ride comfort but also reduces the negative impact on the road surface. In order to evaluate the performance of the control damping (CD) and the control air spring (CAS) of the vehicle air suspension system on the ride comfort and the road friendliness, a three-dimensional (3D) nonlinear dynamic model with 14 degrees of freedom (DOF) of the heavy trucks and optimal fuzzy control (OFC) with control rules optimized by the genetic algorithm (GA) are proposed in this study. The root mean square (RMS) acceleration response of the tractor and the dynamic load coefficient (DLC) at the wheel axles are chosen as objective functions under the various operating conditions. Contrastive analysis of the RMS and DLC values with the passive (P), CD, and CAS methods of the air suspension system is carried out respectively. The research result shows that both the CD and CAS methods remarkably improve the ride comfort and road
Nguyen, Vanliem, Jiao, Renqiang, Zhang, Jianrun
Better Solutions for Testing and Measuring Compression and Extension SpringsTBMG-359562/1/2020
The design, manufacture, and use of springs can be traced back in time to The Bronze Age. Spring design is a science based on complex arithmetic calculations combined with material science. Springs are used in everyday consumer devices including cellular phones and computers, in industrial applications including automotive and aerospace, and in precision medical devices where a spring with a diameter of .0036” (about equal to the size of a human hair) is used in catheters and endoscopic instruments.
Heavy Dump TruckTBMG-3567512/1/2019
Mack Defense Allentown, PA 1 (800) 866-1177
Spring Calculations Using Noonan’s XymT Method and an Eccentric Force03-13-01-000710/14/2019
Abstract The usual method of calculating spring deflection is to assume the end force acts through the central axis of the spring. The author takes a different approach where he calculates the eccentricity of the end force and from this calculates the spring deflection due to combined bending and torsion using a completely new model which he names the Noonan XymT Method. Also, the usual method widely used, where a strain energy approach is used, is proven to be in error. That statement is proven using a special example. Rough measurements have shown that the displacements calculated using the Strain Energy Method, can have errors as high as 40%, at a position up 0.6 coils from the bottom of the spring, and 10% at the top of the spring. The reason for this error has been identified, and calculations using Noonan’s XymT Method greatly reduces, if not eliminates, this error. This is particularly relevant in calculating individual coil stiffness and binding. With the displacement
Noonan, Michael
Miniature Spring Performance TesterTBMG-351409/1/2019
In order to qualify miniature springs, manufacturers of these systems rely on commercially available testers that are designed for large-scale springs (>0.5" diameter). Commercially available spring test systems lack sufficient force resolution or cyclic test capabilities for miniature-scale springs. Traditional spring testers work on the basis of compressing (or extending) a spring to a known deflection and recording that force value, then moving to the second known deflection and recording that force value. This is done manually by a user and has no capability of automation or fatigue.
Minimizing Power Consumption of Fully Active Vehicle Suspension System Using Combined Multi-Objective Particle Swarm Optimization2019-01-50777/16/2019
This paper introduces an optimum design for a feedback controller of a fully active vehicle suspension system using the combined multi-objective particle swarm optimization (CMOPSO) in order to minimize the actuator power consumption while enhancing the ride comfort. The proposed CMOPSO algorithm aims to minimize both the vertical body acceleration and the actuator power consumption by searching about the optimum feedback controller gains. A mathematical model and the equations of motion of the quarter-car active suspension system are considered and simulated using Matlab/Simulink software. The proposed active suspension is compared with both active suspension system controlled using the linear quadratic regulator (LQR) and the passive suspension systems. Suspension performance is evaluated in time and frequency domains to verify the success of the proposed control technique. The simulated results reveal that the proposed controller using CMOPSO grants a significant enhancement of ride
Elsawaf, Ahmed, Metered, H., Abdelhamid, A.
Development of Impact Force 1D Model for Powertrain Component2019-01-15496/5/2019
Electromagnetic valves excellent in sealing properties and resistant to sliding are often used in powertrain equipment installed in gasoline- or diesel-engine vehicles. An electromagnetic valve has the function of moving internal valve members by means of electromagnetic force generated by the application of a voltage and thereby changing the flow path. When an electromagnetic valve operates, however, the valve members impact with one another, emitting impact noise caused by it. With the requirement for low noise in electromagnetic valves having become stricter recently from the viewpoint of comfort in the passenger compartment, predicting the noise is needed at the design stage. With this background, this paper describes the development of a 1D model of impact force that will enable the noise and the product performance to be examined simultaneously for a GDI (gasoline direct injection) high pressure pump. In contrast to the conventional model in which a movable member is taken as a
Yoshimaru, Yuma, Kondo, Makoto, Omuro, Yukie, Inaba, Masashi
S-Curve Time-of-Flight Mass SpectrometerTBMG-344065/1/2019
Time-of flight mass spectrometers are commonly used in analytical chemistry and many other applications. They contain a region where ions travel toward a detector. A new geometry was developed that has improved performance over existing designs.
A Non-Contact Overload Identification Method Based on Vehicle Dynamics2019-01-04904/2/2019
The vehicle overload seriously jeopardizes traffic safety and affects traffic efficiency. At present, the static weighing station and weigh-in-motion station are both relatively fixed, so the detection efficiency is not high and the traffic efficiency is affected; the on-board dynamic weighing equipment is difficult to be popularized because of the problem of being deliberately damaged or not accepted by the purchaser. This paper proposes an efficient, accurate, non-contact vehicle overload identification method which can keep the road unimpeded. The method can detect the vehicle overload by the relative distance (as the characteristic distance) between the dynamic vehicle's marking line and the road surface. First, the dynamics model of the vehicle suspension is set up. Then, the dynamic characteristic distance of the traffic vehicle is detected from the image acquired by the calibrated camera based on computer vision and image recognition technology. The data error caused by the
Zhou, Daolin, Tan, Gangfeng, Ding, Yiran, Yu, Shimin, Ma, Xiaofei, Wang, Shuai, Wang, Zhenyu
Enhanced Coil Spring Modeling in Passenger Car Suspension for Improved Target Setting Process06-12-01-000412/14/2018
The problem addressed in this work is how to formulate accurate targets for coil springs in passenger car suspensions to ensure that the required ride height and wheel rate are achieved. The issue arises because suspensions often tend to introduce significant spring deformations other than a purely axial compression. Although these effects are quite common, their influence on suspension performance is still not well understood. To this purpose, a new enhanced spring model is presented. The theory behind the model is explained and the relationship between spring and suspension performance discussed in detail. To validate formulations, a series of numerical simulations has been carried out demonstrating the model accuracy. Finally, a novel approach to spring target setting is proposed based on this advanced spring model.
Bianco, Roberto
Dynamic Optical Grating Device for Modulating LightTBMG-3339912/1/2018
NASA Langley Research Center has developed a novel optical grating device that dynamically modulates light and is capable of controlling the spectral properties and propagation of light without any moving mechanical components.
Adaptronic Actuator to Minimize the Pins Misalignment on Pin-on-Disc Testers2018-01-189210/5/2018
The Automated Universal Tribotester (AUT) represents a fully automated reduced scale brake dynamometer and was developed by the Institute of Dynamics and Vibrations at TU Braunschweig. The setup is based on the pin-on-disc principle. The downscaled test specimen is brought to contact to the disc, loaded and guided via the load unit, which was specifically designed for this purpose. It is laid out as a combination of parallel and serial leaf springs, facilitating a friction free and horizontal motion. The stiffness in radial and tangential directions are much higher than in normal orientation. If the test specimen has a two-dimensional, flat contact surface, the misalignment of the pin in a Pin-on-Disc setup is a phenomenon that appears even in very stiff and robust Pin-on-Disc testers. The measured friction forces are not sensitive to the tilting movement, but the wear processes that take place in the contact zone are. For investigations of the friction surface, an adaptive adjustment
Vogel, Alexander, Ostermeyer, Georg-Peter
Quick Disconnect for High-Pressure Mate/De-MateTBMG-290536/1/2018
NASA Kennedy Space Center seeks partners interested in the commercial application of the Quick Disconnect for High Pressure Mate/De-Mate. Designed at KSC, this technology is intended for use in dusty environments where dust particles can contaminate high-pressure connectors, resulting in wear on connector surfaces and unreliable connections. The Quick Disconnect (QD) utilizes the gas supplied by the umbilical to spray on, entrain, and remove dust from the connector surfaces prior to mating.
Explanation for Variability in Lower Frequency Structure-Borne Noise and Vibration: Roles of Rear Subframe Dynamics and Right-Left Spindle Phasing10-02-01-00025/17/2018
This investigation focuses on a class of rear suspension systems that contain both direct and intersecting structural paths from the tire contact patches to the vehicle body. The structural paths intersect through a dynamically active rear subframe structure. New experiments and computational models are developed and analyzed in this article to investigate the variability of structure-borne noise and vibration due to tire/road interactions in the lower- to mid-frequency regimes. Controlled operational experiments are conducted with a mass-production minivan on a chassis dynamometer equipped with rough road shells. Unlike prior literature, the controlled experiments are analyzed for run-run variations in the structure-borne noise up to 300 Hz in a single vehicle to evaluate the nature of excitations at the spindle as the key source of variation in the absence of significant manufacturing, assembly and instrumentation errors. Further, a deterministic modal expansion approach is used to
Noll, Scott, Singh, Rajendra
CFD/CSD Aeroelastic Predictions of a Semi-Span TiltrotorF-0074-2018-127095/14/2018
This work focuses on steps towards the ability to use tight coupling between computation fluid dynamics (CFD) and rotorcraft comprehensive analysis (CSD) to predict aeroelastic stability of a rotor. First, the Rotorcraft Comprehensive Analysis System (RCAS) analysis is used to carry out traditional linear stability analysis. Next, a method of using trim springs to artificially increase the stability of the wing so that a periodic solution during the RCAS trim procedure is presented. RCAS is then used to complete time-integrated transient analysis using a lifting-line aerodynamic model following a system perturbation through a vertical force located at the wing tip. CFD/CSD coupling is used for the first time to simulate a fully-elastic semi-span tiltrotor model. Loose coupling is used to achieve a trimmed solution for a sweep of airspeeds. Tight coupling is used to observe the transient behavior of the system following a perturbation. Low-speed results are promising and clearly
Corle, Ethan, Floros, Matt, Schmitz, Sven
Multi-Objective Optimization to Improve SUV Ride Performances Using MSC.ADAMS and Mode Frontier2018-01-05754/3/2018
Ride is an important attribute which must be accounted in the passenger segment vehicles. Excessive H point acceleration, Steering wheel acceleration, Pitch acceleration can reduce the comfort of the driver and the passengers during high frequency and low frequency rough road events. Excessive Understeer gradient, roll gradient, roll acceleration and Sprung mass lift could affect the Vehicle driver interaction during Steady state cornering, Braking and Step steer events. The concept architecture of the vehicle plays an important role in how comfort the vehicle will be. This paper discusses how to improve SUV ride performances by keeping handling performance attributes same or better than base vehicle. Multi Objective Optimization was carried out by keeping spring, bushing and damper characteristic as the design variables to avoid new system or component development time and cost. The first step in this process is DOE (Design of Experiments method) which allows to select critical or
Lenka, Visweswara Rao, Anthonysamy, Baskar, Londhe, Abhijit, Hatekar, Harshad
Suspension Systems: Some New Analytical Formulas for Describing the Dynamic Behavior2018-01-05544/3/2018
The paper presents some new and unreferenced analytical formulae describing the dynamic behaviour of the suspension system of road or off-road vehicles. The quarter car model (2 degrees of freedom) is considered, the suspension can be either passive or active. Passive suspensions can be simplified as the spring-damper combination or the spring-damper combination with an additional in series spring (representing, e.g., the rubber bushing at the top of a McPherson strut or the rubber bushing at the end joints of the damper). The mathematical system is linear and the excitation is given by a random stationary and ergodic process. The standard deviations in analytical form are given referring to, respectively, the vehicle body acceleration, the relative displacement between sprung and unsprung mass, and the force at the ground. The so called invariant points of the frequency response functions are derived for both active and passive suspension. Unreferenced sub-invariant points are derived
Mastinu, Giampiero, Gobbi, Massimiliano, Yang, Liunan, Ramakrishnan, Kesavan, Ballo, Federico
A Comparative Study on Non-Linear Analysis Using Explicit and Implicit Techniques & Fatigue Life Estimation of Semi-Elliptical Leaf Spring2018-01-04724/3/2018
Leaf spring is a vital suspension component, such that the failure of leaf spring could cause fatal accidents. Due to frequent failures of leaf springs on vehicles, a method is developed to perform the numerical analysis using explicit solver which provides insightful analysis of leaf springs to prevent the occurrence of failure during engineering design. Since fatigue life assessment of leaf springs is a significant aspect during the design stage and due to the limitation of non-compatibility of output file of explicit solver for fatigue analysis, various studies are conducted and implicit solver is considered to perform FEA simulation of leaf spring. The present study delineates comparison of non-linear analysis of semi-elliptical leaf spring using explicit solver with that of implicit solver. Analysis using implicit solver gives us an advantage to export the model in fatigue life estimation solver which is not possible using explicit solver. The aim of this study is to establish
Kurna, Srinivas, Mehndiratta, Akhil
LightCensor Software for Optimized Viewing of Medical ImagesTBMG-281811/1/2018
Because of improved display quality, the smartphone has been advocated by medical imaging vendors for viewing medical images in specific conditions that require urgency of results, or when full-sized workstation displays are not readily available. As a handheld device, the viewing conditions of a smartphone (e.g. ambient light and handshaking) are not predictable, and may adversely affect the perceived image quality.
Orthopedics: Springs Provide Precision, CleanabilityTBMG-281341/1/2018
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