Crash reconstruction is a scientific process that utilizes principles of physics and empirical data to analyze the physical, electronic, video, audio, and testimonial evidence from a crash to determine how and why the crash occurred. This course will introduce this reconstruction process as it gets applied to various crash types - in-line and intersection collisions, pedestrian collisions, motorcycle crashes, rollover crashes, and heavy truck crashes. Methods of evidence documentation will be covered. Analysis methods will also be presented for electronic data from event data recorders and for video.
Finite Element Analysis (FEA) has been used by engineers as a design tool in new product development since the early 1990's. Until recently, most FEA applications have been limited to static analysis due to the cost and complexity of advanced types of analyses. Progress in the commercial FEA software and in computing hardware has now made it practical to use advanced types as an everyday design tool of design engineers. In addition, competitive pressures and quality requirements demand a more in-depth understanding of product behavior under real life loading conditions.
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.
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.
A high impetus from Government on road infrastructure development, is giving a fillip to passenger CV space. This has resulted in making the passenger CV segment lucrative enough, thereby pulling in many operators in the business. The quality of road has immensely improved over a decade, as a result of which the average speed and hence the quantum of distance covered by passenger buses has increased significantly. People are preferring to travel in buses over trains, owing to at par ticket cost, high availability, reduced travel time and also improved level of comfort. Aligned to the market need and the trend, OEM's are offering buses with capable powertrains to cater the need of speed, reduced trip time as well as a lot of attention is also being paid to tune in the comfort level for long hauls. A big chunk of passenger travel is catered by the bus operators especially during major festivals in India.
The study aims to evaluate the lateral stability of tractor-front end loader system in consideration with difficult work conditions based on various loader bucket lifting heights from ground while driving a system on transversal slopes. In the proposed method the centre of gravity of tractor-front end loader system was calculated and analysed to evaluate the transversal overturning of the system. This overturning of the system was analysed by applying mathematical equations presented in past studies and compared with the newly developed prediction model for 3 test tractors of 25 HP. The excel spreadsheet comprised of mathematical equations used to calculate the Tractor Stability Index (TSI) on transverse slope with respect to loader bucket height and payload in dynamic condition. A criterion has been defined to categorize the Tractor Stability Index (TSI) poor to excellent on a scale of 0 to 4 where <0 being the very poor, 0-2 Poor, 2-4 Good and >4 being the excellent.
Objective This paper explores the usage of Altair simulation driven optimisation process, Front Suspension hard points of a sedan Car model are optimised for specific target toe curves using MotionView, MotionSolve and HyperStudy This process gives the optimal hard point values to match the target curves without much iterations. Methodology Parametric Multibody model of the front end of sedan is built in MotionView. To Carry out optimisation HyperStudy is used where few of the suspension hard points which affect the toe curves are chosen as design variable. For the chosen Design variables upper and lower bound limits are specified. Ride, Roll and lateral force tests are performed. Optimisation is performed using HyperStudy where it iterates the suspension hard points to match the target toe curves. Each iteration response can be visualized in HyperStudy and can be compared with the target toe curve.
Internal combustion (IC) engines have been serving as prime source of power in tractors, since late 19th Century. Over this period, there have been significant improvements in IC engine technology leading to increased power density, reduction in tailpipe emissions and refinement in powertrain noise of tractors. As the regulations governing tailpipe emissions continue to be more stringent, original equipment manufacturers also have initiated work on innovative approaches such as diesel-electric hybrid powertrains to ensure compliance with new norms. However, introduction of such technologies may impact customer’s auditory, vibratory and drivability perceptions. Absence of conventional IC engine noise, association of electric whistle and whine, torque changes with activation/de-activation of motors and transmission behavior under transient conditions may result in new NVH issues in hybrid electric vehicles.
The use of deposit control additives in European market gasoline is well documented for maintaining high levels of engine cleanliness and subsequent sustained fuel and emissions performance. Co-ordinating European Council (CEC) industry fuels tests have played a crucial role in helping to drive market relevant, effective and low-cost deposit control additives into European market fuels. Until now, there has not been a Gasoline Direct Injection engine test available to fuel marketers in any market globally. However, a new CEC engine test is currently being developed to address that gap. Based on an in-house VW injector coking test, it shows promise for becoming a useful tool with which to develop and measure the performance of deposit control additives. A key requirement of industry tests should be to replicate issues seen in consumer vehicles, thereby providing a platform for relevant solutions.
Title Development of a Graphical User Interface (GUI) Based Tool for Vehicle Dynamics Evaluation Authors Mr. Shubham Kedia, Dr. Divyanshu Joshi, Dr. Muthiah Saravanan Mahindra Research Valley, Mahindra & Mahindra, Chennai Objective Objective metrics for evaluation of major vehicle dynamics performance attributes i.e. ride, handling and steering are required to compare, validate and optimize dynamic behavior of vehicles. Some of these objective metrics are recommended and defined by ISO and SAE, which involve data processing, statistical analysis and complex mathematical operations on acquired data, through simulations or experimental testing. Due to the complexity of operations and volume of data, evaluation is often time consuming and tedious. Process automation using existing tools such as MS Excel, nCode, Siemens LMS, etc. includes several limitations and challenges, which make it cumbersome to implement.
OBJECTIVE Race vehicles are designed to achieve higher lateral acceleration arising at cornering conditions. A focused study on the steady state handling of the car is essential for the analysis of such conditions. The transient response analysis of the car is also equally important to achieve best driver-car relationship and to quantify handling in the range suitable for a racing car. This research aims to investigate the design parameters responsible for the transient characteristics and optimize those design parameters. This research work examines the time-based analysis of the problem to truly capture the non-linear dynamics. Apart from tires, chassis can be tuned to optimize vehicle handling and hence the response times. METHODOLOGY To start with, the system is modelled with governing parameters and simulation is carried out to set baseline configurations. Steady state and transient handling simulations run independent of each other with independent logic, coded on MATLAB.
Squeak and Rattle (S&R) are the dominant undesired noises which adjudge the perceived quality of a vehicle. It's a foremost problem which needs to be identified and eliminated at a design stage to develop a robust vehicle, which also aids in pacifying the physical testing and warranty claim costs. A Finite Element model of the complex plastic dashboard has been analyzed to identify risks and the root cause of S&R problem under dynamic and static loading conditions, using E-line methodology. These complex transient problems are highly influenced by various parameters like gap variability, temperature, the coefficient of thermal expansion, thickness, and material properties. This paper elaborates the detailed investigation conducted using stochastic simulations to evaluate the individual and combined impact of each parameter on S&R performance
Research Objective The importance of evaluating ride comfort with high degrees of accuracy objectively and its correlation with subjective perception is increasing day by day because of the long duration of the driving experience. The complex motion of the vehicle which is the combination of heave, roll and pitch motion is responsible for causing extreme uneasiness to the driver as well as the passenger. In this paper, ride comfort evaluation is done on the highway with similar traffic conditions with the help of Vibration Dose Value Analysis, Suspension Working Space and Ride Diagram methods for two hatchbacks and its correlation with the complex motion like choppiness of the vehicle is established that will help us to enhance the driver ride experience. Methodology The ride testing is performed for two hatchbacks on a highway road with different kinds of terrain ranging from highly uneven road roughness to moderately smooth surface for a speed range of 60-100 kmph.
Ikshit Shrivastava1, Kiranpreet Singh2 1,2 International Centre for Automotive Technology (ICAT), Gurugram, India Introduction: Pass By Noise emitted by the vehicle is one of the most critical tests for certification is vehicle worldwide. There are a number of national and international regulations to define test procedure. Though the available tracks are constructed to meet the requirements of these test standards, but there are other external parameters viz. ambient temperature, barometric pressure, wind speed and its direction, affecting the measurements. These parameters are beyond the control of human and this contamination of test data results in longer test time to monitor atmospheric/ambient conditions and perform the test. Indoor pass-by noise testing is a comparatively new method of testing, which is yet to be evaluated for repeatability/correlation with conventional exterior pass-by noise testing.
The present work involves Machine Learning (ML) based Multi-objective Multidisciplinary Design Optimization (MMDO) for lightweighting the automotive structures. The challenge in deployment of MMDO algorithms in solving real-world automotive structural design problems is the enormous time involved in solving full vehicle finite element models that involve large number of design variables and multiple performance constraints pertaining to vehicle dynamics, durability, crash and NVH domains. With the availability of powerful workstations and using the advanced Computer Aided Engineering (CAE) tools, it has become possible to generate huge sets of simulation data pertaining to multiple domains.
Tyre Traction Trailer is a device designed to find the Peak Brake co-efficient of C2 and C3 tyre as per ECE R117. The trailer is towed by the truck and is braked suddenly to evaluate braking co-efficient of specimen tyre. It is a single wheel trailer equipped with load cell to capture tire loads (Normal and longitudinal)while braking. Traction Trailer is modelled in MSC Adams and rigid body simulation is carried out for static stability of the system. Dynamic simulations were performed to understand locking of wheels during braking. Body frame was further modelled as flex body to perform structural analysis of the frame. The paper contains stress and deformation plots of trailer Structure under various loading conditions, change in Centre of gravity, weight transfer and forces on springs during braking and cornering, plots of tractive and normal load on tyre during braking.