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2015-04-14
Technical Paper
2015-01-1516
Mohammed K Billal
The component level wheel crush test will help to predict the wheel crush load under static condition. In passenger car, the frontal wheel has to absorb the energy during the crush and it should not intrude more in to the occupant compartment. Using virtual tools, the wheel crush load can able to predict for the new designs and the new design changes can be made quickly to meet the requirement. During the wheel crush, the crack will initiate and propagate, then the major failure will occur. In virtually, this failure can be achieved using progressive damage and failure material model. This material model is having the capability to predict the damage initiation due to the ductile and shear failure. After damage initiation, the material stiffness is degraded progressively according to the specified damage evolution response. The progressive damage models allow for a smooth degradation of the material stiffness, in both quasi-static and dynamic situations.
2015-04-14
Technical Paper
2015-01-1517
David Stalnaker, Ke-Jun Xie, Terence Wei
Tire manufacturers need to perform various types of testing to determine tire performance under representative vehicle load conditions. However, test results are influenced by a number of external variables other than tire construction. Vehicle load distribution and suspension properties are some of those external variables which can have a significant effect on tire wear rate and durability. Therefore, in order to measure tire performance in a controlled and repeatable manner, a representative vehicle and associated tire load conditions are needed. Laboratory or indoor tire testing offers many advantages over vehicle fleet testing. It provides a well-defined test environment and repeatable results without influence from external factors. Indoor testing has been largely developed around the process of simulating tire wear performance on a specific reference vehicle, including its specific weight distribution, suspension characteristics, and alignment.
2015-04-14
Technical Paper
2015-01-1514
Deepak Tiwari, Japveer Arora
A typical wheel development process involves designing a wheel based on a defined set of criteria and parameters followed by verification on CAE. The virtual testing is followed by bench level and vehicle level testing post which the design is finalized for the wheel. This paper aims to establish the learnings which were accomplished for one such development processes. The entire wheel development process had to be analyzed from scratch to arrive at a countermeasure for the problem. This paper will not only establish the detailed analysis employed to determine the countermeasure but also highlight its significance for the future development proposals. The paper first establishes the failure which is followed by the detailed analysis to determine the type of failure, impact levels and the basic underlying conditions. This leads to a systematic approach of verification which encompasses the manufacturing process as well as the test methodology.
2015-04-14
Technical Paper
2015-01-1515
Kwangwon Kim, Hyeonu Heo, Md Salah Uddin, Jaehyung Ju, Doo-Man Kim
Due to the relatively high freedom of selection of materials associated with a simple manufacturing method, a nonpneumatic tire (NPT) can be manufactured with a low viscoelastic energy loss material. A highly increasing demand to reduce greenhouse gases drives engineers to explore NPTs. NPTs consisting of flexible spokes and the shear band are still at an early stage of research and development. An optimization study of geometry of NPTs needs to be conducted, which is the objective of this paper. Parametric studies, design of experiments (DOE), and sensitivity analyses are conducted with a hyper-viscoelastic finite element (FE) model to determine the effects of three design variables on rolling resistance; the thickness of cellular spokes, the cell angle, and the shear band thickness.
2015-04-14
Technical Paper
2015-01-1512
Sairom Yoo, Md Salah Uddin, Hyeonu Heo, Jaehyung Ju, Doo Man Kim, Seok-Ju Choi
In an effort to develop tires with low rolling resistance, nonpneumatic tires (NPTs) with low viscoelastic energy loss materials are receiving more attention. For better design of NPTs for better fuel efficiency, one may need to analyze rolling energy loss of NPTs at a component level. The objective of this study is to develop a tool to quantify rolling energy loss and thermal dissipation of NPTs at a component level. For varying vehicle loads and rolling speeds, we suggest a thermo-mechanical model of an NPT with hexagonal cellular spokes to investigate temperature distribution of the NPT caused by hysteresis and convection loss into air. Using a hyper-viscoelastic model developed from a uniaxial (tensile and compression) testing and dynamic mechanical analysis (DMA), a thermo-mechanical model is developed by combining longitudinal shear deformation induced hysteresis and cooling to air.
2015-04-14
Technical Paper
2015-01-1511
Srikanth Sivaramakrishnan, Kanwar Bharat Singh, Peter Lee
Anti-lock Braking System (ABS) is a critical safety component and its performance is crucial for every vehicle manufacturer. The tire plays an important role during an ABS braking maneuver as it is the component that connects the vehicle to the ground and is responsible for generating braking force. The steady-state and transient properties of the tire affect the operation of the vehicle’s ABS system. The main objective of this study is to investigate how tire design changes influence its interaction with the ABS and its eventual effect on stopping distance. This was conducted through an experimental study where tires were built with three levels of variation in carcass stiffness, tread stiffness and tread compound. Following this, ABS braking maneuvers were performed on instrumented vehicles with regular ABS and high-performance ABS using these tires on all four wheels.
2015-04-14
Technical Paper
2015-01-1510
Edoardo Sabbioni, Davide Ivone, Francesco braghin, Federico Cheli
Estimation of friction coefficient and sideslip angle represents a key-point for improving control systems for vehicle safety, e.g. ESP (Electronic Stability Control), VDC (Vehicle Dynamics Control), etc. A model-based approach (state observer or Kalman filter) is generally used on purpose. Benefits induced by in-tyre sensors on sideslip angle and friction coefficient estimation are investigated in this paper. Thus tyre cornering force measurements are added to the ones usually present on-board vehicle (steer angle, lateral acceleration and yaw rate) and used to implement an Extended Kalman Filter (EKF) based on a single-track vehicle model. Tyre-road contact forces are assumed to be provided once per wheel turn by a smart tyre constituted of two tri-axial accelerometers glued on the tyre inner liner. Performance of the proposed observer is evaluated on a series of handling maneuvers and its robustness to road bank angle and tyre/vehicle parameters variation is discussed.
2015-04-14
Technical Paper
2015-01-1509
Deepak Tiwari
Auto market is emerging fast in developing countries moreover customer awareness is also getting increased due to powerful electronic media. Demand for ride comfort, lighter, more efficient, more powerful, quieter, smoother running and longer lasting cars is ever increasing. Ride comfort is affected with numerous vehicle parameters in which tire-wheel balancing contribute to a large extent. Effect of appropriate tire-wheel balancing on over all vehicles' ride comfort and handling is colossal. An unbalanced tire-wheel may have startling effect on vehicles overall performance & ride feel. It also creates vehicle vibrations. This paper essentially focuses on one such issue observed during balancing of tire-wheel assy. In spite of balancing the tire- wheel assy. it was not actually getting balanced and the residual unbalance was evident even after repeated balancing trials.
2015-04-14
Technical Paper
2015-01-1505
Ibrahim A. Badiru
Vehicle pull is a condition experienced by customers where a constant torque at the steering wheel is required to maintain the vehicle on a straight path. Vehicle lead is a condition where a non-zero steering wheel angle is required to maintain a straight path. There are many potential causes for vehicle pull or lead—road condition, suspension asymmetry, and tire characteristics to name a few. Both vehicle pull and lead can cause customer dissatisfaction with the vehicle as well as drive OEM warranty service costs. Electronic Power Steering (EPS) systems have overtaken Hydraulic Power Steering (HPS) as the predominate steering architecture for new passenger vehicles. One of the key benefits of EPS is the ability to program value added features (VAF) into the EPS controller. These features can significantly enhance the pleasure and safety of the driving experience for the customer. EPS pull compensation is a feature that reduces the driver workload to compensate a vehicle pull.
2015-04-14
Technical Paper
2015-01-1504
Ning Wei Bao
A ball screw regenerative shock absorber was designed for the relief of the vehicle vibration and the energy recovery of the vehicle vibration. The effect of its main parameters on the suspension system was numerically analyzed. According to the principle of the ball screw regenerative suspension system, a mathematical model of the ball screw regenerative shock absorber was established regarding the ball screw rotational inertia, the motor rotational inertia, the screw lead and the radius of the screw nut. A suspension dynamic model based on the ball screw regenerative shock absorber was developed combining the road model and the two-degrees-of-freedom suspension dynamic model.
2015-04-14
Technical Paper
2015-01-1501
Ryusuke Hirao, Kentaro Kasuya
Many electronic control components have been introduced into vehicles with the aims of improving their safety and comfort, and saving energy. Various suspension systems have been developed, to reconcile ride feeling with control stability at a high level. Development efforts have been particularly active in the field of semi-active suspension, prompted by its superior energy-saving and cost performance. Algorithm which is based on skyhook control has been applied mostly to the ride comfort control of semi-active suspension system of vehicle. Also, at the time of steering, control for enhancing damping force are commonly used as handling control to restrain transitional roll angle. Therefore, in this development we developed new ride comfort control and new handling control, and constructed a system which uses only vehicle height sensor as dedicated sensor and uses damping force variable damper of pressure control type.
2015-04-14
Technical Paper
2015-01-1500
Marcus Ljungberg, Mikael Nybacka, Diomidis Katzourakis, Gaspar Gil Gómez
This paper present and discusses the process to parameterize an electric power assist steering (EPAS) system, employing solely computer-aided engineering (CAE). It addresses the model and the simulation environment setup as-well-as methods for setting the optimal metric targets, based on correlation studies from expert test drivers. The rationale for the study derives from today’s vehicle manufacturer’s needs, to develop high quality cars in a short period of time that satisfy the consumer needs and to stand out in the competition. Further exploitation of the potentials of simulation and CAE tools is needed to enable quick evaluation of different vehicle concepts and setups without the need of building physical prototypes. The main goal of the current study is to facilitate the aforementioned need by developing and evaluating an optimisation process for the control parameters of an EPAS system by solely using CAE tools.
2015-04-14
Technical Paper
2015-01-1497
Hideaki Shibue, Devesh Srivastava
Torsion beam suspensions are lightweight and low-cost, and they are therefore frequently used for the rear of small front-wheel drive vehicles. The configuration of the suspension is simple and it comparatively consists of fewer components. However, it is difficult to predict their characteristics and satisfy the target of the performance in the early stages of development in particular, because it should realize the various performance elements demanded of a suspension in a single part. A great deal of research has been conducted on the cross-sectional shape of the beam section, but up to the present there has been almost no discussion of the effect of property of the trailing arms on suspension characteristics. This paper discusses tests conducted to study the effect of the rigidity of the trailing arms, and considers the mechanism of that effect.
2015-04-14
Technical Paper
2015-01-1491
Automotive OEMs, insurance agencies and regulatory bodies are continuously looking at various accident statistics and proper ways of evaluating unaccounted (as per current regulations and safety ratings) accident scenarios to improve the safety standards of cars. Small overlap and oblique impacts during which a corner of a car hits a tree or the corner of another vehicle are two such situations. To address these scenarios, IIHS has incorporated small overlap impact in the NCAP rating. Similarly, NHTSA is developing an oblique test to address this. Most of the vehicles which are on road scored low when tested for these impact scenarios. This is mainly because most of the energy-absorbing structures (in a vehicle) such as rails and crush boxes during a high speed crash do not get engaged with the impactor as the overlap is very small.
2015-04-14
Technical Paper
2015-01-1489
Transfer or response equations are important as they provide relationships between the responses of different surrogates under matched, or nearly identical loading conditions. In the present study, transfer equations for different body regions were developed via mathematical modeling. Specifically, validated finite element models of the age-dependent Ford human body models (FHBM) and the mid-sized male Hybrid III (HIII50) were used to generate a set of matched cases (i.e., 192 frontal sled impact cases involving different restraint, impact speeds, severities, and FHBM age). For each impact, two restraint systems were evaluated: a standard three-point vehicle belt with and without a single-stage inflator airbag. Regression analyses were subsequently performed on the resulting FHBM- and HIII50-based responses. This approach was used to develop transfer equations for seven different body regions: the head, neck, chest, pelvis, femur, tibia, and foot.
2015-04-14
Technical Paper
2015-01-1492
Kazunobu Ogaki, Takayuki Kawabuchi, Satoshi Takizawa
We test the mid-size sedan according to NHTSA Oblique test to assess the occupant protection and to provide possible design changes to improve the oblique collision performance. This test result predicted high potential injury for BrIC, chest deflection, and lower extremities. Injury reductions could likely be achieved through optimization of the restraint devices. We focus to reduce the lower extremity injury. Traditionally, lower extremity injuries are often mitigated by reducing the intrusion of the cabin’s dashboard lower region; however, this type of design change can lead to a significant increase in vehicle weight. Increasing the energy absorbed within the engine compartment is more efficient than reinforcing the passenger compartment.
2015-04-14
Technical Paper
2015-01-1490
Tony R. Laituri, Scott Henry, Kaye Sullivan
A study of belted driver injury in various types of frontal impacts in the US field data was conducted. Specifically, subject to the Frontal Impact Taxonomy of Sullivan et al. (2008), injury potential of belted drivers in non-rollover, frontal impacts in the National Automotive Sampling System (NASS) was assessed. The field data pertained to 1985 - 2013 model-year light passenger vehicles in 1995 - 2012 calendar years of NASS. Two levels of injury were considered: AIS2+ and AIS3+. For ease of presentation, we grouped the injury data into lower- or upper-body regions. Frontal impacts were binned into eight taxonomic groups: Full-engagement, Offset, Narrow, Oblique, Side-swipe corner, High/low vert (i.e., over- and under-ride crashes), DZY-No rail (i.e., distributed crashes, but with negligible frame rail involvement), and Other. The results of the survey yielded insights into the distribution of belted-driver injury in NASS.
2015-04-14
Technical Paper
2015-01-1488
Adam G.M. Cook, Moustafa El-Gindy, David Critchley
This work investigates the multi-objective optimization methods for Front Underride Protection Devices (FUPDs) using varying meta-modeling and direct optimization techniques, while implementing several materials and minimizing cost of the design. The developed dsFUPD F9 design for a Volvo VNL was subjected to a modified ECE R93 quasi-static loading to objectify deformations. A developed application was needed to objectify the cost as a third target objective to minimize with mass and deformation of the design. NSGA-II, SPEA-II genetic algorithms and adaptive simulated annealing optimization methods were under investigation in combination with three meta-modeling techniques; Feedforward Neural Network, Radial Basis Function Network, and Kriging. Leapfrog LFOPC algorithm hybridized forms of genetic algorithms and adaptive simulated annealing was also investigated.
2015-04-14
Technical Paper
2015-01-1486
Craig A. Markusic, Ram Songade
Full vehicle crash simulations typically require several days of effort from a highly skilled FE (finite element) analyst to set-up, execute, and analyze. The goal of this project was to create a simplified FE model of a side crash utilizing the same sophisticated software (LS-DYNA) that the FE analysts use along with a custom graphical user interface (GUI) that will allow an inexperienced user to set-up, execute, and analyze a number of side impact scenarios in a matter of hours, not days, and with very little training. The GUI allows the user to easily modify the performance characteristics of the side impact system that are critical to side crash performance including but not limited to intrusion rate, door liner stiffness, side airbag stiffness, side airbag time to fire, etc. The user can then compile and submit the model with a few simple clicks of a button.
2015-04-14
Technical Paper
2015-01-1534
Daisuke Nakamura
Reducing drag contributes to greater fuel efficiency and exhaust gas reduction. Regarding aerodynamic performance, every detail must be considered and resistance must be reduced. A vehicle’s package design—the vehicle's fundamental framework—must be considered. This paper introduces factors that contribute significantly to drag . The paper also discusses methods for improving aerodynamic performance. To balance exterior design with aerodynamic performance, a shape that improves aerodynamic performance must be proposed early on. We used 1/4 scale clay models to identify and analyze areas having a significant aerodynamic impact. More than 500 total variation measurements were conducted for 16 items. Based on the results of these measurements, analysis of flow-field was conducted using CFD.
2015-04-14
Technical Paper
2015-01-1526
Yasuyuki Onishi, Thomas Ramsay, Timothy Juan, James McKillen
A sports car exhibits many challenges from an aerodynamic point of view: drag that limits top speed, lift - or down force - and balance that affects handling, brake cooling and insuring that the heat exchangers have enough air flowing through them under several vehicle speeds and ambient conditions. All of which must be balanced with a sports car styling and esthetic. Since this sports car will apply two electric motors to drive front axle and a high-rev V6 turbo charged engine in series with a 9-speed double-clutch transmission to drive rear axle, additional cooling was required, yielding a total of ten air cooled heat exchangers. It is also a challenge to introduce cooling air into the rear engine room to protect the car under severe thermal conditions.
2015-04-14
Technical Paper
2015-01-1522
Takahiro Yokoyama, Koji Hiratsuka, Shinya Notomi
Users drive at relatively high speeds during the winter season, and maneuvering on snow-covered roads is a key performance for drivers. Demands are increasing for tires with lower rolling resistance. Tire patterns were developed similar to summer tires with reduced grooving and tire patterns with shallower grooves. This required techniques that predict maneuverability on snow-covered roads. This study treated maneuverability on snow-covered roads as maneuverability in the grip region, and verified the correlation between subjective evaluation using vehicles and tire stand-alone characteristics. Indexes were clarified for the tire contact patch and the physical properties of the tread rubber, which are prerequisites for securing grip in the normal-use. Typical index values for indexes were investigated using the surface pressure distribution obtained by a tire contact and surface pressure measuring system.
2015-04-14
Technical Paper
2015-01-1523
Takahiro Uesaka, Tatsuya Suma
Simulating road noise while a vehicle is operating shortens the development period and reduces the number of prototypes, which lowers development costs. Realizing road noise simulation identifies the force transmitted to the suspension through the tires and wheels from vibration between the road surface and the tires. There are significant variations between static state characteristics and vibration characteristics of tires in motion, which are challenging to measure. The effects of reduction of the elastic modulus of the rubber in the tires due to repeated loads accompanying contact with the ground, and of Coriolis and centrifugal forces resulting from the rolling motion are known. Detailed analysis of the eigenvalue fluctuations produced by Coriolis force based on measurements taken using sensors installed inside the tires has recently been reported. Knowledge is still lacking in areas such as the specifics of how the input from the tires changes due to these fluctuations.
2015-04-14
Technical Paper
2015-01-1518
Emmanuel O. Bolarinwa, Oluremi Olatunbosun
Three-dimensional (3D) Finite element (FE) tyre models have been widely used for tyre design, vehicle design and dynamic investigations. Such tyre models have the inherent advantage of covering a wide range of tyre modelling issues such as the detailed tyre geometry and material composition, in addition to an extensive coverage of tyre operational conditions such as the static preload, inflation pressure and driving speed. Although tyre vibration behaviour, in different frequency ranges are of general interest, both for the vehicle interior and exterior noise, the present study is limited to a frequency of 100 Hz which is prevalent in most road induced NVH ride and handling problems. This study investigates tyre vibration behaviour using a propriety FE code. Such investigation plays an important role in the study of vehicle dynamics.
2015-04-14
Technical Paper
2015-01-1519
Robert Suender, Günther Prokop, Thomas Roscher PhD
Starting from the USA in 2008 and followed by the European Union commencing in 2012, legal requirements concerning “Tire Pressure Monitoring Systems” (TPMS) for passenger cars and light trucks will be introduced in China as well and therefore in the third of the three largest automobile markets worldwide. Changes of pressure dependent physical tire properties such as dynamic roll radius and a certain tire Eigen mode, which are included in the ABS-wheel speed signals, indicates pressure loss in an indirect manner. Systems with corresponding working principles are called “indirect Tire Pressure Monitoring System” (iTPMS). Since the tire is a structural element with varying characteristics according to the design parameters, the roll radius and frequency behavior due to pressure loss is variable as well. As a consequence, tires have to be evaluated regarding there compatibility to iTPMS during the vehicle development process.
2015-04-14
Technical Paper
2015-01-1521
Kanwar Bharat Singh, Srikanth Sivaramakrishnan
Tread depth, inflation pressure, tire temperature, and road surface condition are among the most notable factors that have a noticeable effect on the tire force and moment characteristics. They can vary significantly during the operation of a tire and can effectively modify tire (and thus vehicle) performance. This study presents details of an adaptive magic formula (MF) tire model capable of coping with changes to the tire operating condition. More specifically, extensions have been made to the magic formula expressions for tire cornering stiffness and peak grip level, to account for variations in the tire inflation pressure, load, tread-depth and temperature. As a next step, the benefits of using an adaptive tire model for vehicle control system applications is demonstrated through simulation studies for enhanced vehicle control systems using an adaptive tire model in comparison to traditional control systems based on a non-adaptive tire model with fixed model parameters.
2015-04-14
Technical Paper
2015-01-1439
Toshiyuki Yanaoka, Yasuhiro Dokko, Yukou Takahashi
To evaluate vehicle safety performance for Traumatic Brain Injuries (TBIs) in crashes, comprehensive injury criteria is required. Few research results for injury criteria focused on Diffuse Axonal Injury (DAI) in crashes or pedestrian impacts exist. We developed injury criteria based on the rotational rigid body motion of the head for occupant and pedestrian crashes. We used the mid-sized male human head/brain FE model to investigate correlation between injury criteria based on the rotational rigid body motion of the head and intracranial responses related to DAI. The input pulses applied to the skull of the head/brain model were determined from the head acceleration data, and articulated rigid body simulation results of frontal occupant and pedestrian crashes. Results showed low applicability of the injury criteria to pedestrian impacts, presumably due to the maximum rotational velocity occurring before head contact to the vehicle.
2015-04-14
Technical Paper
2015-01-1442
Wolfgang Sinz, Jörg Moser, Christoph Klein, Robert Greimel, Karsten Raguse, Class Middendorff, Christina Steiner
Precise three-dimensional dummy head trajectories during crash tests are very important for vehicle safety development. To determine precise trajectories with an accuracy of approximately 5 millimetres, three-dimensional video analysis is an approved method. Therefore the tracked body is to be seen on at least two cameras during the whole crash term, which is often not given (e.g. head dips into the airbag). This non-continuity problem of video analysis is surmounted by numerical integration of differential un-interrupted electrical rotation and acceleration sensor signals mounted into the tracked body. Problems of this approach are unknown sensor calibration errors and unknown initial conditions, which result in trajectory deviations above 10 centimetres.
2015-04-14
Technical Paper
2015-01-1431
Mark H. Warner, Jon Bready, Wyatt Warner
Snowmobile acceleration, braking and cornering performance data are not well developed for use in accident reconstruction. Acceleration and braking data were published by D’Addario et. al. in SAE 2011-01-0287 which reported results of acceleration and braking testing on 4 snowmobiles of various make and model. This paper expands on the previous work and presents the results of new on-snow tests which include acceleration, braking and cornering maneuvers that have not been published previously. Maximum and average cornering speeds and resulting lateral accelerations are presented for turns of radius 15, 30 and 60 feet on level packed snow. Variation is reported between novice and expert riders in cornering applications. Performance values are also reported for acceleration, braking, and cornering tests where a passenger is included. All tests were performed on a level surface with consistent snow conditions throughout.
2015-04-14
Technical Paper
2015-01-1432
Jeffrey Aaron Suway, Judson Welcher
Accident reconstruction experts are often asked to evaluate the visibility and conspicuity of objects in the roadway. It is common for some of these objects, and required by Federal Motor Vehicle Safety Standard (FMVSS) No. 108 for certain vehicles and trailers, to have red and white DOT-C2 retroreflective tape installed on several locations. Retroreflective tape is designed to reflect light back towards the light source, at the same entrance angle. FMVSS No. 108 has performance requirements for retroreflective tape at different entrance angles, up to 45 degree. The federal requirement for minimum performance of the retroreflective tape at 45 degrees is significantly less than the federal requirement for minimum performance of the retroreflective tape at 4 degrees. Additionally, the federal requirement for the minimum performance of white retroreflective tape is significantly different than the federal requirement for the minimum performance of red retroreflective tape.
Viewing 1 to 30 of 104045

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