Browse Topic: Noise, vibration, and harshness standards and regulations

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Prediction and Optimization of Noise radiation from a Heavy-Duty Commercial Vehicle Transmission using Statistical Energy Analysis2025-01-005105/05/2023
Heavy Duty (HD) linehaul vehicles are majorly used in transportation of goods and heavy loads between different cities or long distances. Considering the current trend, payload capacity of these heavy-duty trucks are increasing due to constant increase in the load demand. Due to which engine torques of these HD vehicles are increasing which in turn increases the transmission input torque. At higher torque levels, gear excitation also increases and transmission becomes more susceptible towards higher noise radiation. Global vehicle pass-by noise regulations for HD commercial vehicles are becoming more stringent. Historically transmissions have been considered a secondary noise source but with overall HD vehicle noise becoming quieter, the transmission can be more of a significant noise contributor. Hence, noise radiation from the transmission is also an important factor to be considered in the design phase. Gear whine is the major concern for sound radiation from the transmission. The
Rastogi, Sarthak, Milind, T. R.
Modeling and Validation of Acoustic Emissions in Bent-Axis Pumps2025-01-005605/05/2023
This work presents a comprehensive NVH workflow for modeling the acoustic emissions of mechanical systems, using a bent-axis pump as a case study. The workflow integrates multibody dynamics (MBD), harmonic structural analysis, and acoustic solvers. By employing these simulation tools, we capture the dynamic response of the pump and the vibration response of the enclosure's surface, enabling the estimation of equivalent radiated power (ERP) and the prediction of sound pressure level (SPL). To validate the simulation outcomes, experimental investigations were conducted in a semi-anechoic chamber, where data was collected with a microphone placed at a specific distance from the pump. At the time of this abstract, preliminary correlations between the simulation model and real-world measurements demonstrate promising accuracy and reliability. These findings are significant, offering advantages for pump manufacturers, including improved product quality, adherence to noise regulations, and
Kwarta, Michael, Banerjee, Bhaskar, Abdel Mallak, Zuher, Vallebrant, Per-Ola, Wiklund Lång, Marcus, Kayani, Omer
Design, Manufacturability, Optimization, and Validation of a Reactive-Style Muffler for a Formula SAE Race Car2025-01-002405/05/2023
The noise generated by internal combustion engines, particularly in high-performance vehicles like Formula SAE race cars, presents a significant challenge in adhering to strict competition noise regulations. To address this issue, mufflers are essential for reducing acoustic emissions. This study focuses on the design, manufacturability, optimization, and validation of a reactive-style muffler specifically for a Formula SAE combustion competition car. The proposed muffler utilizes two chambers to generate destructive interference, targeting the two dominant exhaust frequencies of the Honda CBR600RR engine to maximize transmission loss and reduce noise levels below the SAE-mandated range of 103–110 dB(C). A 3D model of the muffler was developed using SolidWorks, capturing the precise geometries required for acoustic optimization. The exhaust noise and muffler performance were simulated using GT-Suite, allowing for an evaluation of noise attenuation across engine speeds. Experimental
Labao, Kai, Middleton, Nicholas, Nuszkowski, John
Reduction of Aeroacoustics Tonal Noise for a Tractor Cooling Fan2021-26-029909/22/2021
Currently, noise pollution has become one of the major environmental concerns. To address this, new noise standards and regulations are being introduced and mandate the tractor OEM's to meet the defined noise levels. Fan noise from the cooling fan is one of the key contributors to the overall vehicle noise. Hence, the reduction of fan noise at the source is a very important and critical task. Even though fan noise is broadband in nature its aerodynamic noise sources are most dominant at the higher harmonics of the blade pass frequency (BPF). Aerodynamic noise of a fan can be varied by changing the fan geometry viz. blade profile, fan width & diameter, no. of blades, and ring on its periphery. Cooling fan is an important component of the cooling system which ensures adequate airflow for radiator cooling and avoids engine overheating with uniform heat dissipation. The important parameters that need to be considered while designing a cooling fan are noise level, airflow, and power
Avinash, D., Shankar, M, Maller, Rathish, V, Ravindran
Acoustic Model Reduction for the Design of Acoustic Treatments2021-01-105708/31/2021
Due to constant evolution in both noise regulations and noise comfort standards, noise reduction inside the vehicle remains one of the main issues faced today by the automotive industry. One of the most efficient methods for noise reduction is the introduction of acoustic treatments, made of multilayered trimmed panels. Constraints on these components, such as weight, packaging space and overall sound quality as well as the amount of possible material and geometrical combinations, have led automotive OEMs to use innovative methods, such as numerical acoustic simulation, so as to evaluate noise transmission in a fast and cost-effective way. While the computational cost for performing such analyses is insignificant for a limited number of configurations, the evaluation of multiple design parameter combinations early in the design stage can lead to non-viable computation times in an industrial context. This paper presents a framework for the efficient, almost real-time evaluation of
Poulos, Athanasios, Jacqmot, Jonathan, Baudson, Romain, Kayvantash, Kambiz, Le Corre, Sandrine
Sound Measurement - Construction SiteJ1075_202107 (Current)07/15/2021
This SAE Standard sets forth measurement procedures and instrumentation to be used for determining a “representative” sound level during a representative time period at selected measurement locations on a construction site boundary. The document is not intended for use in determining occupational hearing damage risk. Determination of a representative time period is left to the judgment of the user.
OPTC3, Lighting and Sound Committee
Enhanced Windshield NVH Modeling for Interior Cabin Noise2020-01-110004/14/2020
The windshield is an important component in vehicle NVH performance. It plays an integral role in affecting the interior cabin noise. The windshield acts as a large panel typically oriented near vertical at the front of vehicle’s acoustic cavity, hence modeling it appropriately is key to have a reliable prediction of cabin interior noise. The challenge of modeling the windshield accurately rises from the structural composition of different types of windshields. For automotive applications, windshield come in several structural compositions today. In this paper, we will discuss two types of windshield glass. First is a typical laminated glass with polyvinyl butyral (PVB) layer and second is a typical acoustic glass with PVB and vinyl layers. Acoustic glass improves acoustics characteristics of the glass in frequencies of ~ 1200 Hz to ~4000 Hz range. Low frequency interior cabin noise studied with FEA is typically below 500 Hz. The acoustic glass doesn’t provide any benefits in this
Abbas, Ahmad, Elwali, Wael, Thirukonda, Aravindhan, Haider, Syed, Sturla, Francisco
Human Response to Vibrations and Its Contribution to The Overall Ride Comfort in Automotive Vehicles – A Literature Review2020-01-108504/14/2020
The various factors that affect ride comfort have been in focus in many research studies due to an increasing demand in ride comfort in the automotive industry. Noise, vibration and harshness (NVH) and the human response to NVH has been highlighted as an important contribution to assess and predict overall ride comfort. The purpose of this paper is to present an approach to explain ride comfort with respect to vibration for the seated occupant based on a systematic literature review of previous fundamental research and to relate these results to the application in the contemporary automotive industry. The results from the literature study show that numerous research studies have determined how vibration frequency, magnitude, direction, duration affect human response to vibration. Also, the studies have highlighted how body posture, age, gender and anthropometry affect the human perception of comfort. An analysis was made of the consistency and inconsistency of the results obtained in
Wang, Xiaojuan, Osvalder, Anna-Lisa, Höstmad, Patrik, Johansson, Ingemar
Road Noise Prediction Assessment Using CAE Instead Of Costly And Time Consuming Physical Tests2020-01-049204/14/2020
Virtual Product Development (VPD) with a vision to eliminate prototype testing is the trend in automotive industry. Reducing the total vehicle development period with optimized output has been the major requirement of this new trend, fueled by increasing competition and shorter product life cycle. In this regard, Computer Aided Engineering (CAE) has taken more significant role than ever in the vehicle development programs. Prediction of road noise in passenger car is one of the important attribute to NVH Simulations. In the present work, CAE - NVH simulation of road noise is carried out on the Finite element model of the vehicle, eliminating the costly and laborious test procedures. An alternative to the existing MBD/Test input method is explored in this work. Generating the load inputs for the structure-borne road noise in a cost and time saving method with accuracy is one of the challenges in these simulations. Enforced displacements in the frequency domain are generated using ISO
S, Vishnu, J, Prajith, Holla, Muralidhara, Suhas, Patil, Bhattacharyya, Indranil
Independent Aftermarket (IAM) and the Three Dimensions of Friction Material Evaluation2019-36-000601/13/2020
It is well known the difference between development levels and engineering investment applied to passenger car brake pads when compared to Original Equipment Manufacturer (OEM) and items sold in the Independent Aftermarket (IAM). Based on these differences, the objective of this paper is to propose a simple evaluation for the IAM that can provide at least some level of the understanding of frictional material behavior. Based on a tripod of variables, or three Dimensions Development, described in this work as Performance, Comfort (NVH) and Durability; and using internationally and established testing procedures to measure these dimensions in order to meet the IAM demands for the cost-benefit engineering investment. An important part of the proposed tool is to position friction material against competition for market known issues, and, more importantly, to ensure end product safety and reliability.
Oliveira, Pedro, Rodrigues, Henrique, Ferro, Eduardo
GKN spreads premium propshaft tech to quiet pickup cabins19AUTP10_1110/01/2019
It may seem a long way in engineering and NVH terms from premium European cars such as Audi's A5 and A7 to light duty trucks, but GKN Automotive has bridged that gap with its latest lightweight all-wheel drive (AWD) modular propshaft. Many pickups suffer a significant amount of unwanted NVH emanating from the front propshaft, with its two universal or CV joints and an interconnecting shaft positioned below and close to the passenger cabin. But now GKN Automotive has “re-characterized” its premium car driveline system to an entirely different vehicle category. “With a traditional truck front propshaft, the level of noise entering the cabin is perceived as a drone,” explained Michael Miller, GKN's propshaft product technology manager. “We've worked on applications of our new technology where the cabin NVH levels have been dramatically reduced. Positive results stem from the combination of joints used in our lightweight modular front propshaft.”
Birch, Stuart
Frequency Inspection of Brake System Components2019-01-211709/15/2019
Frequency inspection has long been a tool utilized by manufacturers of brake system components as a means of quality control. This is important to combat perceived defectiveness of a system that experiences issues, such as brake squeal, as well as to identify actual defects in the parts going out to customers. Every component has its own resonance frequencies based on the dynamics of that component. Knowledge of the resonance frequencies of each component provides insight that can prevent manufacturers from sending out defective units, whether they be perceived defects or actual defects. NVH engineers who understand these phenomena perform theoretical analysis and acquire experimental data in the lab to gain insight into their parts that will eventually be produced on the assembly line. Unfortunately, the frequency requirements, and the consequences thereof, defined by the NVH engineers can still remain somewhat of a mystery to the manufacturing engineers who are tasked with applying
Cagle, Robert
The Influence of Differential Pad Wear on Low-Frequency and High-Frequency Brake Squeal2019-01-213009/15/2019
The NVH behavior of disc brakes in particular, is in the focus of research since a long time. Measurements at a chassis dynamometer show that brake pad wear has a significant influence on the occurrence of low- and high-frequency squealing [1]. It is suspected that high-frequency squealing is more likely to occur when the wear difference between the inner and outer brake pad is small. In the other case, if the differential wear rate between the inner and outer pads becomes higher, the prevalence of low-frequency squealing increases. In order to examine this hypothesis, this work focuses on a simplified model of a commercial brake system [2]. In a first step, the inner pad’s wear is iteratively increased, while the wear on the outer pad remains unaffected. In a second step, the coefficient of friction at the worn pad is iteratively increased to investigate the influence on the low and high-frequency squealing. With the aid of the Complex Eigenvalue Analysis (CEA), the real part of the
Otto, Johannes, Ostermeyer, Georg-Peter, Rhee, Seong K.
Robust NVH Engineering Using Experimental Methods - Source Characterization Techniques for Component Transfer Path Analysis and Virtual Acoustic Prototyping2019-01-154206/05/2019
A major challenge in automotive NVH engineering is to approach complex structure-borne sound and vibration problems with sufficient accuracy but reasonable experimental effort. Typical issues encountered are poor correlation between objective component performance criteria tested for during bench validation and corresponding subjective targets evaluated during system validation in the actual vehicle. Additional challenges arise from the need to impose assumptions on sophisticated physical vibration problems to reduce the complexity to a level feasible for conventional experimental test methods. This paper addresses all mentioned issues by elaborating on a system NVH engineering approach employing Virtual Acoustic Prototyping (VAP) (related to what is now often called component Transfer Path Analysis) to synthesize time domain sound and vibration responses of vibrating machinery operated in a virtual vehicle environment. One crucial step of VAP is to characterize the strength of
Wienen, Kevin, Sturm, Michael, Moorhouse, Andy, Meggitt, Joshua
Open-Access Testbench Data for NVH Benchmarking of E-Machines under Electromagnetic Excitations2019-01-145906/05/2019
This paper presents an experimental setup dedicated to the analysis of noise and vibration due to Maxwell magnetic forces in electrical machines, a significant NVH source in hybrid and electric vehicles traction motors. Both electromagnetic excitations and structural response of the electrical machine are simplified to provide the first public benchmark of e-NVH phenomenon (electromagnetic Noise, Vibration, Harshness). The paper first describes how the testbench is designed and tested in order to reduce as much as possible modelling and experimental uncertainties. A Permanent Magnet Synchronous Machine topology used in EV/HEV applications is used to illustrate tooth modulation effect and interaction between radial and tangential force-induced vibrations, and designed to generate the resonance of several stator structural modes with simplified electromagnetic loading (open-circuit case). A larger air gap allows the insertion of a fine search-coil network to measure time and space
Devillers, Emile, Degrendele, Karine, Hecquet, Michel, Lecointe, Jean-Philippe, Le Besnerais, Jean, Cousin, Guillaume
Integrated Multi-Physics Simulation for Full-Vehicle Low Frequency NVH Optimization in HEVs2019-01-145506/05/2019
The recent automotive industry trend towards electrification has created new challenges for NVH engineers. These challenges stem from new powertrain architectures and their complex interactions, the governing control strategies which aim to optimize energy management, and new unmasked sources of excitation. Additionally, vehicle manufacturers are attempting to reduce hardware testing in order to rapidly satisfy increasing production demand and to minimize its costs. Hence, to meet the above-mentioned challenges up front in the development process of Hybrid Electrical Vehicles (HEVs) while balancing competing design objectives of drivability, durability and NVH, a simulation-led design and optimization is required. NVH problems are often the result of mechanisms that originate through complex interactions between different physical domains (flow, electromagnetic, structural/mechanical, control logic, etc.) and the assembly of individual components into a complete system. Therefore
Gomez, Llorenc Foraste, Zeman, Jonathan, Liu, Jack
New Method for Decoupling the Powertrain Roll Mode to Improve Idle Vibration2019-01-158806/05/2019
Modern engines have high torque outputs and have low RPM due to increased demand for fuel efficiency. Vibrations caused by such engines have to be mitigated. Decoupling the roll mode from the remaining five rigid body modes results in a response which is predominantly about the torque roll axis (TRA) and helps reduce vibrations. Therefore, placing the mounts on the TRA early in the design phase is crucial. Best NVH performance can be obtained by optimizing the powertrain mount parameters viz; Position, Orientation and Stiffness. Many times, packaging restricts the mounts to be placed about the TRA resulting in degradation in NVH performance. Assuming that the line through the engine mount (Body side) centers is the desired TRA, we propose a novel method of shifting the TRA by adding mass modifying the powertrain inertia such that the new TRA is parallel to and on top to the desired TRA. This in turn will decouple the roll mode and reduce vibrations. This problem is formulated as an
Haider, Syed F., Abbas, Ahmad, Sturla, Francisco
The New Challenges of NVH Package for BEVs2019-01-145206/05/2019
Battery electric vehicles (BEVs) bring new challenges when it comes to NVH package development, which are affected by many new factors. The noise sources from the powertrain are different, for instance due to the presence of tonal components, strong harmonics and potential whining noise. Another important aspect is the missing effect of masking noise from a combustion engine. As a consequence, other noise sources, such as tires, become more predominant. This means that the NVH package has to be re-engineered considering new noise sources and cannot just be significantly decontented in general. At the same time, NVH package weight reduction should at least partly counterbalance the vehicle weight increase due to the presence of a large and heavy battery pack in order to maximize the driving range. In the early days of BEVs, OEMs mostly carried over technologies used on combustion engine vehicles to electric cars. With the development growth of specific vehicle platforms for electric
Lepoittevin, Grégoire, Horak, Jan, Caprioli, Davide
Structural Vibration and Acoustic Analysis of a 3-Phase AC Induction Motor2019-01-145806/05/2019
This paper aims to study the NVH and acoustic performance of a 3-phase AC induction motor in order to develop an approach to reduce the magnetic component of noise from an electric motor in an electric vehicle (EV). The final goal of this project is to reduce the magnetic component of sound from the motor by making modifications to the end bracket of the motor housing. EVs are being considered the future of mobility mainly due to the fact that they are environment-friendly. As many companies are already investing in this technology, electric drives are set to become extremely popular in the years to come. The heart of an EV is its motor. Modern electric vehicles are quiet, furthermore with the lack of an IC engine to mask most sounds from other components, the sound from the electric motor and other auxiliary parts become more prominent. The primary source of electromagnetic noise in a motor arises from magnetic flux variations in the air gap which interfere with the resonant
Krishnasarma, Anand, Taylor, Allan, Baqersad, Javad, Poozesh, Peyman
Benefit of a Lightweight Frunk2019-01-145606/05/2019
Due to the increasing number of battery electric vehicles (BEVs), the engineering fields regarding driving comfort and NVH issues are becoming more and more challenging: many new factors affect the development of BEVs NVH package. The noise sources related to the powertrain are different from the traditional ones of internal combustion engines, for instance due to the presence of tonal components, strong harmonics and potential whining noise. To satisfy NVH specifications and the need for lightweight solutions to increase driving range, it is important to mask as much as possible the noise coming from the engine bay with materials both lightweight and acoustically performing. Moreover, for electric vehicles new interesting solutions are possible with the introduction of new components that do not find room under the hood of ICE or hybrid vehicles. These components, if properly designed, could lead to significant NVH benefits. The present paper reports the NVH effects of one of these
Di Marco, Federico, Pezzani, Flavio, Daving, Andreas, Mazzarella, Luca
Role of Dynamic Stiffness in Effective Isolation2019-01-149506/05/2019
In any machinery, avoiding noise and vibration completely is a difficult task due to the structural dynamic behaviors of components. To safeguard the operator, it is important to best isolate the operator station from NVH environment. Cabin isolation is an important aspect to minimize structure borne noise and tactile vibrations to be transferred into the cabin. Isolators are selected based on the isolation system inertial properties at mounting locations in the operating frequency range interested. The most important assumption to select isolators are that the active side and passive side of the isolators are nearly rigid so impedance mismatch is created for effective isolation. This paper describes the importance of dynamic stiffness of the structures on both the active and passive side for better NVH performance. NVH performance of passive side is evaluated analytically and computationally in terms of tactile vibrations and structure borne noise for various ratios of the dynamic
Dasabai, Balavardhan Reddy, Yang, Yuzhen
Design Optimization of Differential Bevel Gear for NVH Improvement2019-01-155206/05/2019
With fast pacing development of automobile industry and growing needs for better driving experience, NVH performance has become an important aspect of analysis in new driveline product development especially in hybrid and electric powered vehicles. Differential bevel gear has significant role in the final drive. Unlike parallel axis gears such as spur or helical gear, bevel gear mesh shows more complicated characteristics and its mesh parameters are mostly time-varying which calls for more extensive design and analysis. The purpose of this paper is to conduct design study on a differential bevel gear unit under light torque condition and evaluate its NVH characteristics. Unloaded tooth contact analysis (UTCA) of those designs are conducted and compared for several design cases with different micro geometry to investigate their pattern position and size variation effects on NVH response. Loaded tooth contact analysis (LTCA) that is based on semi-analytical and semi-FE method is used to
Shi, Zhenghong, Chen, Jui, Kolivand, Mohsen, Sun, Zhaohui, Kopp, Gregory, Peng, Ying
Target Development for Transmission and Electric Motor NVH2019-01-155406/05/2019
It is a common practice to conduct NVH fingerprinting and benchmarking assessments at the powertrain level, to understand source level noise and vibration. To assess the NVH influence of engine, e-motor, and transmission, sub-system testing is often conducted in addition to full powertrain testing. These powertrain or sub-system investigations provide valuable information regarding the status of “source” level excitations relative to targets and / or competitive powertrains. In the case of transmissions and e-machines, it is particularly important to understand source level tonal content and how this will be perceived at the vehicle level. However, variation in component design results in differences in order content, which complicates the process of objectively comparing multiple products. Multiple methods are presented here for characterizing tonal content of transmission and e-machines, based on assessments conducted in a component hemi-anechoic dynamometer test cell. Ultimately
Tousignant, Todd, Ford, Alex, Govindswamy, Kiran, Dech, Justin, Vanhaaften, Frederick, Hettenhouse, Matthew
Investigation on Cyclic Noise in Vehicle Creeping during Stop-Go Traffic Conditions2019-01-155706/05/2019
Now-a-days, customers are turning more sensitive towards vehicle NVH performance. In order to enhance customer NVH comfort, a specific noise phenomenon was investigated during product development. While testing stop-go traffic conditions, cyclic noise was observed in the 1st gear with the vehicle creeping. The noise was similar to a gear rattling noise. It was perceived unpleasant due to low background noise and wide frequency range of cyclic noise. This paper explains the root cause of this cyclic noise through various drivetrain experiments and also elaborates the experimental analysis approach in order to arrive to the solution in gear and clutch design for cyclic noise elimination.
Vaishya, Abhishek Lakhanlal, Pujara, Archan Sunibhai, Khare, Devendra Kumar, Satpathy, Kingshuk
Use of Active Vibration Control to Improve Vehicle Refinement while Expanding the Usable Range of Cylinder Deactivation2019-01-157106/05/2019
Cylinder deactivation has been in use for several years resulting in a sizable fuel economy advantage for V8-powered vehicles. The size of the fuel-economy benefit, compared to the full potential possible, is often limited due to the amount of usable torque available in four-cylinder-mode being capped by Noise, Vibration, and Harshness (NVH) sensitivities of various rear-wheel-drive vehicle architectures. This paper describes the application and optimization of active vibration absorbers as a system to attenuate vibration through several paths from the powertrain-driveline into the car body. The use of this strategy for attenuating vibration at strategic points is shown to diminish the need for reducing the powertrain source amplitude. This paper describes the process by which the strategic application of these devices is developed in order to achieve the increased usage of the most fuel efficient reduced-cylinder-count engine-operating-points.
Orzechowski, Jeff, Agnihotri, Gaurav, Juneja, Vikas
Development and Application of an Objective Metric for Transient Engine Clatter Noise2019-01-151906/05/2019
Several powertrain noise phenomena have been studied over the years. Sound quality metrics, like loudness, sharpness, modulation, and tonality, among others, have been developed to characterize powertrain noises. While these readily available metrics work well on steady state and some transient noises, they do not correlate directly with subjective impressions. Moreover, it is difficult to assign a meaningful single rating for time varying noises that may also be associated with simultaneous variations in frequency content. This paper summarizes the process of creating a vehicle level objective metric and its application to blind noise samples to verify correlation with subjective impressions, particularly in association with clatter noise at moderate engine speeds (2000-3500 rpm) with light to moderate throttle tip-ins. The main results include a single number rating and a rating curve as a function of engine speed useful for comparative NVH assessments of multiple vehicles or of
Parbat, Aniket, Charan, Anil
Application of Model Order Reduction to Nonlinear Finite Element Tire Models for NVH Design2019-01-150706/05/2019
In current practice, tire development and testing are typically experimentally driven. However, as the need to simultaneously optimize multiple noise vibration and harshness (NVH) performance criteria increases and development cycles become shorter, predictive numerical simulation techniques are becoming necessary. In addition, many tire performance areas are coupled and therefore the experimental approach often lacks detailed insights which numerical simulations can provide. Currently, no industrially applicable fully predictive high-fidelity numerical approach that incorporates the use of nonlinear Finite Element (FE) tire models for NVH design is available in literature. Therefore, a fully predictive numerical simulation approach that predicts the rolling of a tire over a coarse road surface is described in this work. The proposed approach allows to predict the dynamic contact- and hub forces that arise during rolling without the need for experimental data. Based on these results
De Gregoriis, Daniel, Naets, Frank, Kindt, Peter, Desmet, Wim
Reducing Vehicle Interior NVH by Means of Locally Resonant Metamaterial Patches on Rear Shock Towers2019-01-150206/05/2019
Stringent regulations for CO2 emissions and noise pollution reduction demand lighter and improved Noise, Vibration Harshness (NVH) solutions in automotive industries. Designing light, compact and, at the same time, improved NVH solutions is often a challenge, as low noise and vibration levels often require heavy and bulky additions, especially to be effective in the low frequency regime. Recently, locally resonant metamaterials have emerged among the novel NVH solutions because of their performant NVH properties combined with lightweight and compact design. Due to the characteristic of stop band behavior, frequency ranges where free wave propagation is inhibited, metamaterials can beat the mass law, be it at least in some tunable frequency ranges. Previously the authors demonstrated how metamaterials can reduce the vibrations in a simplified shock tower upon shaker excitation. In this work, the authors apply the metamaterial concept on the real rear shock towers of a vehicle. In order
Sangiuliano, Luca, Claeys, Claus, Deckers, Elke, De Smet, Jasper, Pluymers, Bert, Desmet, Wim
Target Setting Process for Hybrid Electric Drives Using TPA, Jury Study, and Torque Management2019-01-145306/05/2019
The idea of improved efficiency without compromising the “fun to drive” aspect has renewed the auto industry’s interest toward electrification and hybridization. Electric drives gain from having multiple gear ratios which can use advantageous operating set points thus increasing range. Furthermore, they benefit significantly from frequent decelerations and stopping as is experienced in city driving conditions. To recuperate as much energy as possible, deceleration is done at high torque. This presents an interesting but serious sound quality issue in the form of highly tonal whine harmonics of rapidly changing gears that do not track with vehicle speed thus being objectionable to the vehicle occupants. This paper presents an NVH target setting process for a hybrid electric transmission being integrated into two existing vehicles, one belonging to the premium segment and another aimed at enthusiasts with off-road applications. The demand for power has shifted from mechanical domain into
Singh, Vinod, Parbat, Aniket, Charan, Anil
Driveline NVH Integration of An NA Truck Program2019-01-155906/05/2019
In the current automotive industry, it is common that the driveline subsystem and components are normally from different automotive suppliers for OEMs. In order to ensure proper system integration and successful development of driveline system NVH performances, collaboration efforts between OEMs and suppliers are very demanding and important. In this paper, a process is presented to achieve successfulness in developing and optimizing vehicle integration through effective teamwork between a driveline supplier and a major OEM. The development process includes multiple critical steps. They include target development and roll down, targets being specific and measurable, comprehension of interactions of driveline and vehicle dynamics, accurate definition of sensitivity, proper deployment of modal mapping strategy, which requires open data sharing; and system dynamics and optimization. More specially, the supplier can work with OEM to seek the most cost-effective solutions, through tuning
Peng, Ying, Shi, Zhenghong, Folts, Christopher, Kopp, Gregory, Sun, Zhaohui, Sandstrom, Alexander
New Half Shaft Bench Test Methodology for NVH Characterization2019-01-155806/05/2019
The main purpose of this paper is to develop a reliable bench test to understand the vibratory behavior of the half shafts under applied torque comparable to an idle condition. In some cases, the half shaft path is a major factor influencing the idle vibration in the vehicle. At idle condition vehicle vibrations are caused by engine excitation and then they pass through different paths to the body structure. Half shaft manufacturers generally characterize shaft joints for their frictional behavior and typically there is no data for vibration characteristics of the half shaft under idle conditions. However, for predictive risk management, the vibratory behavior of the half shaft needs to be identified. This can be achieved from measured frequency response functions under preloaded test conditions. This bench test enables manufacturers to conduct comprehensive design of experiments on the impact of powertrain vibration input while transmitting through the half shaft into the vehicle
Siavoshani, Saeed, Vesikar, Prasad Balkrishna, Yuan, Wei, Abbas, Ahmad, Sturla, Francisco Antonio
Model Verification of CAE with NVH-Test Acting on Downsized Car Engines2019-01-155006/05/2019
Today’s trend of combustion engine development for cars is characterized with; high torque, low engine speed, low weight, high degree of cyclic irregularity, low excitation frequency due to fewer cylinders active e.g. 4-cylinder or less. This implies in respect of vibrations that it is crucial to control powertrain rigid body modes and place these were they cannot be reached and induced by the low exciting harmonic frequencies for low engine speeds or idling. It is also important to control the overall flexible vibration modes. A mathematical CAE model is created in simulation software AVL-EXCITE in order to handle the vibration phenomenon as a first step. But it is absolutely necessary to “verify” these models with real measurements in respect of NVH and if needed upgrade the CAE model if there are detected deviations. The NVH-test is done with testing tool DEWESoft. The purpose of below paper is to do model verification on a concrete example in respect of powertrain vibrations. Volvo
Rönnqvist, Urban, Ribarits, Janos
Determining Vibro-Acoustic Characteristics and Structural Damping of an Elastic Monolithic Panel2019-01-153806/05/2019
Evaluations of the dynamic and acoustic responses of panels, partitions, and walls are of concern across many industries, from building home appliances, planning meeting rooms, to designing airplanes and passenger cars. Over the past few decades, search efforts for developing new methodologies and technologies to enable NVH engineers to acquire and correlate dynamically the relationship between input excitations and vibro-acoustic responses of arbitrary-shaped panels has grown exponentially. The application of a particular methodology or technology to the evaluation of a specific structure depends intimately on the goals and objectives of the NVH engineers and industries. In this work, we present the comparisons between the traditional modal analyses for structural vibrations together with sound intensity measurements of sound radiation and a laser-assisted Helmholtz equation least squares (HELS) method [1, 2, 3, 4] to characterize the dynamic and acoustic responses of an arbitrarily
Figueroa, Antonio, Wu, Sean, Chen, Lingguang
Augmenting Vehicle Production Audit with Objective Data and Sound Quality Metrics to Improve Customer Experience in a Changing Automotive Landscape2019-01-153106/05/2019
Vehicle manufacturers face increasing challenges in auditing the build quality of their vehicles while considering increasing consumer demands regarding NVH performance. This effect is compounded with the rise in electric and hybrid vehicles. The ability to audit vehicles for a variety of noise types is becoming increasingly important; these include powertrain noise, road noise, and wind noise. An automated measurement system was developed with specific algorithms and sound quality metrics to not only audit vehicle production quality but to add objective data, pass-fail criteria, and trend analysis.
Thom, Brian, Cerrato, Gabriella, Sturgill, Mark
A Case Study on Golf Car Powertrain NVH Sources and Mitigation Methods2019-01-147806/05/2019
The golf market has remained flat in North America. Whereas, it has grown worldwide. A trend is seen where the number of young adults and adults over the age of 65 years involved with the game has increased. The demographics in golf showing the most growth also have high standards for the operation of the golf car. They have transcended their expectations to align with some of the qualities expected of automobiles. There is a shift in consumer expectations. Moreover, the market competition has also increased. This drives the OEMs to deliver refined golf cars with NVH being a key aspect in development. This paper showcases a recent study to improve the powertrain N&V performance of an internal combustion engine golf car. Primarily, a test-based approach is followed. Chassis rolls and on road testing are performed for benchmarking and target setting. System and component tests are performed to root cause issues. The tests further help to provide input for mitigation methods for
Carter, Steven, Buczek, Kenneth, Clark, Adam, Pathak, Mayuresh
System Interactions Affecting NVH Performance of an Electric Vehicle Drivetrain2019-01-154506/05/2019
The paper will present an integrated approach to system NVH analysis, which gives an insight into the system response in an EV driveline due to electrical and mechanical excitations; namely rotor mechanical imbalance, electrical machine torque ripple, and stator radial force shapes. The paper will address the fact that, as part of a practical design exercise, different subsystems and components may achieve design maturity at different times. It is therefore important to understand to what extent various drivetrain components may be considered in isolation, and at what point it becomes necessary to consider the interactions present in the full system. The paper will compare predicted NVH performance of a representative EV traction motor when different boundary conditions are considered; for example, when considering the motor being bested in isolation as part of a typical test setup, and when included in a representative drivetrain. For each configuration, the response to mechanical and
Michon, Melanie, Holehouse, Robert, Shahaj, Annabel, Jafarali, Hisham, Janakiraman, Venkatakrishna
Gear System Parameters and Its Influence on Gearbox Noise2019-01-156206/05/2019
Tonal noise due to gears is one of the fundamental noise problems in a gearbox. Gear tooth deflections generate dynamic forces that lead to unwanted load fluctuations, thus noise. Different factors that are considered to control this noise, some to mention like proper gear macro design, microgeometry corrections, and housing compliance. However, identifying the appropriate variable as a measure of contribution to the overall response helps in getting more accurate remedial solutions. Some outputs to track are different harmonic components of TE, temperature effects, components of forces, rim compliance and friction. For evaluation, usually, the amplitudes of individual harmonics of transmission error are related to the respective orders of the noise levels assuming it as one of the primary excitation parameters of gear noise. In this paper, a brief overview of TE and its harmonic distribution is discussed with the example of an ideal gear mesh model and then quantifying TE with the
Dewangan, Yogesh Kumar, Nair, Pranoy Sureshbabu, Nair, Dipin
Optimization of Hypoid Gear Tooth Profile Modifications on Vehicle Axle System Dynamics2019-01-152706/05/2019
The vehicle axle gear whine noise and vibration are key issues for the automotive industry to design a quiet, reliable driveline system. The main source of excitation for this vibration energy comes from hypoid gear transmission error (TE). The vibration transmits through the flexible axle components, then radiates off from the surface of the housing structure. Thus, the design of hypoid gear pair with minimization of TE is one way to control the dynamic behavior of the vehicle axle system. In this paper, an approach to obtain minimum TE and improved dynamic response with optimal tooth profile modification parameters is discussed. A neural network algorithm, named Back Propagation (BP) algorithm, with improved Particle Swarm Optimization (PSO) is used to predict the TE if some tooth profile modification parameters are given to train the model. With the optimal hypoid gear tooth profile modification, a system level analysis of vehicle axle system is performed to verify the improvement
Lin, Chia-Ching, Wang, Yawen, Wang, Kan, Zhang, Weiqing, Sun, Shouli, Lim, Teik C.
Interior Floor Engineering: The Dynamic-vs-Static-Stiffness Compromise2019-01-149306/05/2019
When it comes to the design of multi-functional automotive interior floors, engineers face the challenging conflict between a dynamically-soft, NVH performing treatment, and a statically-stiff construction, which increases the perception of solidity. Nowadays, the former requirement is well-specified and advanced CAE tools exist to support performance prediction and engineering of the construction. On the contrary, neither well-established requirements specify the compressional performance, nor defined CAE processes are available to support the engineer in its prediction. In this context, the aim of this paper is twofold. Firstly, insightful conclusions about the compression behavior of typical interior floor materials are drawn by means of tests carried out both at sample- and part-level. Such an analysis allows highlighting a clear direction towards meaningful assessment of the mechanical characteristics of the floor. Secondly, the paper focuses on how CAE tools can support part
Pezzani, Flavio, Godano, Philippe, Ronzio, Francesca, D'Amico, Roberto
NVH Aspects of Electric Drive Unit Development and Vehicle Integration2019-01-145406/05/2019
The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. Specifically, the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 reduction targets for 2025 and beyond. This will also include a strong growth in the global demand for electric drive units (EDUs). The change from conventional vehicles to vehicles propelled by EDUs leads to a reduction in overall vehicle exterior and interior noise levels, especially during low-speed vehicle operation. Despite the overall noise levels being low, the NVH behavior of such vehicles can be objectionable due to the presence of tonal noise coming from electric machines and geartrain components as well as relatively high shares of road/wind noise. In order to ensure customer acceptance of electrically propelled vehicles, it is imperative that these NVH challenges are understood and solved. This
Wellmann, Thomas, Tousignant, Todd, Govindswamy, Kiran, Tomazic, Dean, Steffens, Christoph, Janssen, Peter
Paradigm shift in NVH19AUTP06_0206/01/2019
A new wave of vehicle technologies is changing the way Brüel & Kjaer attacks noise, vibration and harshness. When you're in the business of NVH solutions, you get to know noise and vibration up close and personal. And for these experts, it can be difficult to sequester the ‘N and V’ throughout their own day. Ask Dr. Gabriella Cerrato, manager of global sound and vibration engineering services at Brüel & Kjaer. “I can't be in a hotel room and not be aware of things like the refrigerator compressor, the ice maker, or the air conditioning,” she noted. “Although I'm not a geek about it-I don't immediately ponder the sources and potential noise paths of the hotel HVAC, for example-it sometimes drives me nuts.”
Brooke, Lindsay
Foam for NVH solutions19AUTP06_0506/01/2019
New innovations for a wide variety of sound-deadening applications.
Everything brake science and technology1243705/16/2019
Over 800 braking professionals from all corners of the industry will gather at Orlando's JW Marriott Grande Lakes Resort for the 37th annual installment of the Brake Colloquium and Exhibition this coming September. Join engineers, executives, management and marketing professionals for four full days of networking and immersive discussion and learning about brake design, emissions, materials, NVH, testing and more. Plus, discover the new technology and solutions driving the next generation of brakes on a bustling show floor of over 85 exhibitors. Register today at sae.org/brake.
Parameters Analyses and Identification for Rubber Bush Based on Theoretical Dynamic Model with Effects of Temperature and Preload2019-01-127204/02/2019
A series connection of the KVBC (Kelvin-Voigt and Bouc-wen) theoretical model of rubber bush in automobile suspension is established. The numerical calculation model is also developed through Matlab/simulation and 9 parameters are identified. Experiments are conducted on the rubber bush on a bench for dynamic and static characteristics and to supply appropriate and reliable data for parameter identification. Based on this, preload and temperature are taken into consideration in an ordinary KVBC model as two important additional factors. As a result, it leads to developing a novel model with new parameter identification, which is validated under different conditions. This new modeling method of rubber bush has three advantages. First, it shows improved accuracy for solving non-linear problems in a multi-body calculation, which is useful for researchers and vehicle engineers. In addition, this new method leads to a very important step for choosing appropriate bush model type before
He, Rong, Zhou, Hong
Automotive Engineering: March 201919AUTP0303/01/2019
Rethinking the HUD Advanced tech solutions move toward augmented reality to bring greater capability to head-up displays. Motor matters New designs and materials are key to the next generation of electric machines for EV propulsion. Harnessing the power of Sim Serious cost savings could come from eliminating vehicle- and systems-level tests. Powerful simulation tools may be the only way to tackle the increasing complexity in mobility development. An OBE for the SAE Meet Paul Mascarenas-SAE International's 2019 president. He's a staunch advocate for professional development for engineers amid the mobility industry's transformation. Solving the propulsion puzzle Must-attend expert panels at SAE's WCX '19 will cover the propulsion-tech future like no other. Editorial Kill the EV tax credit by 2025 SAE Standards News SAE and Synopsys collaborate on cyber study Supplier Eye New Co. vs. Old Co. What We're Driving Supra's revival is Toyota's spin on German engineering 2020 Explorer is the
BIOT’s Parameters Evaluation and Prediction of Flat and Molded Dash Panel Acoustic Performance and It’s Validation2019-26-019501/09/2019
In today’s automotive industry sound package material design and optimization is important considering the need for weight reduction and achieving targeted sound absorption and sound transmission loss values. As per traditional approach vehicle level noise reduction targets are defined considering flat samples, but in actual vehicle condition molded trimmed parts are used. This paper discusses about the systematic methodology developed for molded sample characterization in terms of BIOT’s properties. Effects of different parameters like area wise thickness variation, density variation on BIOT properties is studied. Comparison of BIOT’s properties of flat and molded dash sample is done to study the effect of molded structure. Using these BIOT’s properties prediction of sound absorption and sound transmission loss results carried out using FTMM approach for flat sample and SEA approach for molded sample. These predicted results validated with experimental sound absorption and sound
Joshi, Manasi P., Jain, Sachinkumar, Kamble, Jr., Prashant Prakash, Karanth, Nagesh Voderahobli
Performance Evaluation of Two Wheeler Brake System Using Coupled Thermo-Mechanical Simulation2018-01-189610/05/2018
Safety aspect has been a key requirement in designing braking system. However, non-safety aspect like NVH and thermal performance are gaining equal importance. High engine capacity (cc) motorcycles are prone to thermal and NVH issues as braking energies are more. Therefore, virtual validation of brake disc system by considering both dynamic and thermal load with predefined assumptions is a toughest challenge when confronted with reality boundary conditions. Thus, the paper comes in a unique way of coupling dynamic and thermal load executed between multi body dynamics (MBD) and heat transfer equation which will convey results closer to real time scenario. MBD solves motion and the dynamic influence on heat transfer is calculated using “sliding boundary condition”. A series of repeated braking condition are performed on front brake disc of motorcycle. The results obtained from the analysis shows critical temperature rise. As a consequence, disc thickness variation (DTV) due to thermal
Sukumaran, Suraj, Kalani, Dinesh, Suryavanshi, Yogesh, Kokane, Girish, Deshpande, Moresh, Kharul, Ravindra
Closures weatherstrips with variable cross sections2018-36-015209/03/2018
Closures systems performance is a trade-off between NVH (Noise, Vibration and Harshness) and DCE (Door Closing Efforts) requirements. Dynamic sealing performance and sheet metal rigidity are the key contributors for a stable system. The seals actuate like a spring on the system. Higher seal load is good for NVH performance, adding more dumping to the system, but it will negatively affect DCE, as it will demand additional energy to close the system. Nominal seal load must be defined to achieve a balance between these attributes. This study is about dynamic sealing profiles with variable seal load, which provides tunable solutions to address the trade-off between NVH and DCE on the side doors or rear closures. Dynamic sealing weatherstrips are made of sponge EPDM extruded profiles with a specified load, defined by its CLD (Compression Load Deflection), which is given by the cross section design. While standard extrusion process produces a single cross section profile, a new extrusion
Filho, Rineu Santamaria, Fromel, Ingo, Osti, Reinaldo
The Use of “Big Data” for the Analysis and Design of Vehicle Sound Packages2018-01-157006/13/2018
With the ever-decreasing timescales and increased performance requirements afforded to OEM’s, it has become essential that NVH suppliers provide optimum palliative solutions that comply with a vehicles acoustic targets. The acoustic effect of any palliative treatment attached to a vehicle body system depends on its ability to attenuate noise energy passing through or radiating from the system or its interaction with reflected sound from other areas. Acoustic performance uses targets relating to sound insertion loss (SIL) and / or sound absorption and these are identified to the component supplier by the OEM at the “request for quotation” (RFQ) stage. For many potential suppliers, especially those with a limited portfolio of material options, success or failure is quite straightforward. However, the problem occurs when the material and processing opportunities cover wide parameters and the available combinations and permutations are extensive. It is no longer a simple choice to get the
Morris-Kirby, Rod
Stationary Sound Level Measurement Procedure for Recreational MotorboatsJ2005_201806 (Current)06/12/2018
This SAE Recommended Practice establishes the procedure for determining if recreational motorboats have effective exhaust muffling means when operating in the stationary mode. It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Marine Technical Steering Committee
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