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To establish the correlation in between Computer Aided Engineering & physical testing of automotive parts returnable case (Stacktainer).

International Centre for Automotive Technology-Ashish Singh
  • Technical Paper
  • 2019-28-2569
To be published on 2019-11-21 by SAE International in United States
Automotive returnable cases (Stacktainers) are being used to transport the automotive parts through surface & seaways. No automotive manufacturer wants to spend money on woods, paper & cardboard again and again, it`s better to pay once for robust & reusable cases. these provide better protection to parts from its manufacturing to assembly line of vehicle. While transporting, any kind of crack or failure of returnable cases may lead to loss of money, human & time. To ensure the safety, these pallets have to be validated for vibrations coming from surface irregularities, sea waves & load due to stacking of cases one above other. The objective of this study is to establish a correlation in between the physical testing & simulation in Computer added Engineering (CAE) of automotive returnable case (Stacktainers). There are different types of tests considered to validate the returnable case, rough road evaluation, Multi-axial Vibration & strength evaluation. After conducting the physical test & CAE simulation, a correlation & confidence level up to 90% is established.
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Noise & Vibration challenges in an Electric Vehicle (Bus), its effect and possible reduction techniques

International Centre for Automotive Technology-Ikshit Shrivastava
  • Technical Paper
  • 2019-28-2493
To be published on 2019-11-21 by SAE International in United States
Ikshit Shrivastava1, Kiranpreet Singh2 1,2 International Centre for Automotive Technology (ICAT), Gurugram, India Introduction: Noise and Vibrations is a vast field of study and has been a constant challenge to Acousticians and designers. IC engines have been in existence since almost 125 years and have given enough room & time to acousticians and engineers to develop materials and tune powertrains to minimize Noise and Vibrations from vehicles. With the advent of technology to evolve alternate fueled powertrains to reduce emissions emitted by IC engines, lot of research is being carried out to develop powertrains particularly in the area of Hybrids & Electrics. Substantial investments are being made by OEMs worldwide on researching xEV domain to tap new motor/ battery technologies for vehicles. Since the technology in xEVs is majorly different, the problems associated with them are also different. IC Engines were known to create Noise in running condition, whereas Electric Vehicles are seen as no noise emitting products. The challenge is not just to create a vehicle with zero noise and vibrations inside of the…
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REDUCTION OF STEERING VIBRATION WITH THE APPLICATION OF DYNAMIC TESTING AND ANALYSIS

John Deere India Pvt Ltd.-Amol Pimpale, Prashant Bardia, Pankaj Vaste, Rohit Pawar
  • Technical Paper
  • 2019-28-2421
To be published on 2019-11-21 by SAE International in United States
KEYWORDS: Steering System, Engine Vibrations, Dynamics, Modal Testing, Modal Analysis, ABSTRACT - In modern agriculture, the tractor’s use is indispensable and essential for various operations like cultivation, soil preparation, pulverization and many more. However, despite being efficient machines, tractors may be subjected to different level of vibrations in various parts of their structure. The vibration often plays the key cause of invalidation and component failures and also, affecting the ride and comfort. Since it is known that such vibration factors can affect the behavior in many ways, an understanding of their dynamic response is warranted. In this paper, case study related to reduction of steering system vibration is presented. Objective and Background: Vibration reduction is linked with the reduction either at source or on path. For such, it is necessary to know the reality of machines, component and mechanisms to mitigate the vibration levels on the tractor. From the testing and analysis of the components, it is possible to calculate the dynamic properties and vibration average level. The vibration reduction decreases the damages caused by…
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Study on Engine Start Vibration Index in a Hybrid Powertrain Using Torque Sensor and Cylinder Pressure Sensor

Tsinghua University-Fuyuan Yang, Lei Du, Yaodong Hu
Published 2019-11-04 by SAE International in United States
This paper presents an investigation of drivability issue of engine start-stop. Hybrid vehicles provide excellent benefits regarding fuel efficiency and emission. However, vibration results from constant engine start and stop events generate drivability issues, thus compromising driving comfort. This paper has designed a high speed torque sensor to capture instantaneous torque at the engine shaft. Its consequences help to find out the most suitable index of vibration severity. This paper is organized in four sections. The first section introduces the powertrain to be studied. The second section introduces development of a specially designed torque sensor. The torque sensor is installed between the engine and ISG (Integrated Starter Generator), alongside with an encoder. The torque sensor is utilized to collect the instantaneous shaft torque on occasion of engine start. In the third section, this paper has performed two experiments. Firstly, a typical engine start process (from 0 to 650 rpm) is studied. Instantaneous shaft torque, encoder signal and cylinder pressure signals are gathered and synchronized. Cranking phase and initial combustion phase is observed. It is concluded…
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Optimal Speed Profile for Minimum Vibration during Engine Start Using Pontryagin’s Minimum Principle Approach

Tsinghua University-Lei Du, Liangfei Xu, Yaodong Hu, Minggao Ouyang, Fuyuan Yang
Published 2019-11-04 by SAE International in United States
An imperceptible engine start is critical to the acceptance of hybrid vehicles. This paper focusses on an optimal control problem that tries to reduce vibration during engine start. Efforts are made to obtain the optimal speed trajectory that could cause minimum vibration during engine start. In the first section, the target diesel powertrain is introduced. A four cylinder diesel engine is coaxially paralleled with an ISG motor. The ISG motor serves as the engine starter and engine flywheel. Its dynamic model is established using crank-link dynamics. Secondly, an index is brought out to evaluate the severity of vibration. The cylinder pressure variation is the main cause of engine torque ripple, which in turn results in engine speed fluctuation. The square of the angular acceleration is chosen as the index of vibration. The index shows a positive relation of cylinder pressure in terms of amplitude. Then, the author models this problem as a continuous-time optimal control problem with a fixed terminal time and a partially free terminal state, then solve it by the Pontryagin’s minimum principle.…
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A Novel Method of Improving Ride Comfort of Two Wheeler by Optimization of Seat Parameters

Carmel Polytechnic College-Francis Augustine Joseph
Saingits College of Engineering-Arun Kottayil Varghese
Published 2019-10-11 by SAE International in United States
Two-wheeler plays a significant role in personal transportation in India. People prefer two-wheelers, which has better fuel economy, comfort, and performance. It is vital to enhance comfort, as the seat is in direct contact with the user. Better user comfort improves the vehicle feel and behavior. Dynamic comfort analysis is necessary to understand and improve the vibration characteristics of the human-seat system. The vibration characteristics under analysis are Natural frequency, Maximum transmissibility, Attenuation frequency, and Transmissibility at 6 Hz. A test set-up was developed to collect data samples with different seat characteristics. The data collected from the seat are IFD, Hysteresis, Air-Permeability, Resilience, Thickness, and Mass. The relation between the seat parameters and vibration characteristic is established by statistically analyzing the data. Best seat was identified by ranking vibration characteristics. Correlation analysis determines the best seat by subjective rating of the sample and seat vibration ranking.
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Effective Powertrain Isolation of Off-Highway Vehicles

John Deere Technology Center-Devendra Mandke, Balavardhan Reddy Dasabai, Sandeep Burli
Vellore Institute of Technology-Pushpak Sakhala, Sharan Chandran
Published 2019-10-11 by SAE International in United States
A Powertrain is one of the major sources of excitation of a vehicle vibration and noise in off highway vehicles. It typically has a significant contribution in whole vehicle NVH characteristics. The structure borne energy of the powertrain is transmitted to the chassis and rest of the vehicle through powertrain mounts. Hence, it is of prime importance to design an effective powertrain mounting system in such a way that it will reduce vehicle vibrations to improve vehicle NVH as well as ride comfort, resulting in an effective vibration isolation system and ensuring long service life. In this paper, a newly developed an analytical tool for effective design of isolation system is discussed. For this model, powertrain is considered as a six degree-of-freedom system. Analytical calculations are implemented to find optimum mount design parameters i.e. stiffness, orientation and position of isolators to meet desired NVH targets. To achieve a good isolation characteristic, there is a necessity of decoupling of rigid body modes using optimization of various decoupling methods, which further helps in reducing the forces transmitted…
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Experimental Investigation on Mechanical Properties and Vibration Damping Frequency Factor of Kenaf Fiber Reinforced Epoxy Composite

Hindustan Institute of Technology and Science-Sathish Kumar Rajamanickam, Sivakumar Sattanathan, Deenadayalan Ganapathy, Joshuva Arockia Dhanraj
Sri Krishna College of Engineering and Technology-Vishnuvardhan Ravichandran
Published 2019-10-11 by SAE International in United States
Kenaf Fiber regarded as industrial crop for different applications. It is one of the most important plants cultivated for natural fibers globally. Natural fibers such as kenaf fibers are getting attention of researchers and industries to utilize it in different composites due to its biodegradable nature. In this present investigation mechanical properties, vibration damping frequency factor and thermogravimetric analysis of kenaf fiber reinforced epoxy composite (KFREC) have been evaluated and reported. The tests were conducted with different weight categories of kenaf fiber such as 20%, 25%, 30% and 35%. The effects of fiber content on tensile, flexural, impact strengths, hardness and thermal decomposition properties of the composite were determined. The failure mechanism and damage features of the KFREC were categorized using Scanning Electron Microscope (SEM). The results indicate that the increase in the fiber content decreases the damping vibration factor (ζ) correspondingly. The lowest value of the damping vibration factor was recorded as 0.033 for 35% weight content of Kenaf fiber in the composite. The maximum value of hardness, tensile, flexural, and impact strengths were…
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Ride Index Structure and Development Methodology

Vehicle Dynamics Standards Committee
  • Ground Vehicle Standard
  • J2834_201910
  • Current
Published 2019-10-09 by SAE International in United States
This recommended practice defines methods for the measurement of periodic, random and transient whole-body vibration. It indicates the principal factors that combine to determine the degree to which a vibration exposure will cause discomfort. Informative appendices indicate the current state of knowledge and provide guidance on the possible effects of motion and vibration on discomfort. The frequency range considered is 0.5 Hz to 80 Hz. This recommended practice also defines the principles of preferred methods of mounting transducers for determining human exposure. This recommended practice is applicable to light passenger vehicles (e.g., passenger cars and light trucks). This recommended practice is applicable to motions transmitted to the human body as a whole through the buttocks, back and feet of a seated occupant, as well as through the hands of a driver. This recommended practice offers a method for developing a ride performance index but does not specifically describe how to apply this index to assessment or comparison of specific vehicles.
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Optimizing NVH for EVs

Automotive Engineering: October 2019

Lindsay Brooke
  • Magazine Article
  • 19AUTP10_03
Published 2019-10-01 by SAE International in United States

Unique acoustic and harmonic challenges require an integrated approach to simulation and analysis. An expert at Adaptive Corp. explains.

Despite global sales market share stuck at single-digit levels, electric vehicles (EVs) are steadily filling the development pipelines at major OEMs. And as engineers are acutely aware, EVs bring a paradigm shift in the noise, vibration and harshness (NVH) arena. Their harmonic spectra are dramatically different than those of even the smoothest, most refined combustion-engine vehicles and hybrids.

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