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There has been a rapid increase in popularity of multipurpose All-terrain vehicles (ATV) across the globe over the past few years. SAE BAJA event gives student-community an opportunity to delve deeper into the nitty-gritty of designing a single seat, four-wheeled off road vehicle. The design and development methodology presented in this paper is useful in conceptualization of an ATV for SAE BAJA event. The vehicle is divided into various subsystems including chassis, suspension, drive train, steering, and braking system. Further these subsystems are designed and comprehensively analyzed in software like SolidWorks, ANSYS, WINGEO and MS-Excel. The 3-D model of roll cage is designed in SolidWorks and analyzed in ANSYS 9.0 for front, rear and side impact along with front and side roll-over conditions. Special case of wheel bump is also analyzed. Weight, wall thickness and bending strength of tubing used for roll cage are comprehensively studied.

Two methods are allowed in ISO 26262-5 for hardware analysis of random hardware failures. The 1st method is called “Evaluation of Probabilistic Metric for random Hardware Failures”. The 2nd method is called “Evaluation of each cause of safety goal violation”. Advantages of the 2nd method during development of ASIL D Generation 3 Electric Power Steering are presented in this paper. A reliability analysis is one of the important prerequisite for the hardware analysis and this paper shows the best practice for hardware part failure rate estimation using industry standards such as IEC TR 62380. The equally important focus is on a diagnostic coverage of each safety mechanism with respect to residual faults and with respect to relevant dual/latent point faults because any safety design can either benefit from low failure rates or from high diagnostic coverage of safety mechanism to mitigate faults. FMEA is highly recommended by ISO 26262-5 as a part of hardware analysis.

While much research has focused on improving terrain mobility, energy and fuel efficiency of terrain trucks, only a limited amount of investigation has gone into analysis of power distribution between the driving wheels. Distribution of power among the driving wheels has been shown to have a significant effect on vehicle operating characteristics for a given set of operating conditions and total power supplied to the wheels. Wheel power distribution is largely a function of the design of the driveline power dividing units (PDUs). In this paper, 6×6/6×4 terrain truck models are analyzed with the focus on various combinations of PDUs and suspension systems. While these models were found to have some common features, they demonstrate several different approaches to driveline system design.

It is always a challenging task for the braking industry to maintain consistent friction material behavior during brake system development. Lack of consistency in friction behavior causes significant disruptions in efforts to integrate friction material with the foundation brake system. This is especially true when new friction formulations and/or manufacturing processes are introduced during an application program. Furthermore, every new program has new requirements that introduce new challenges and issues to the brake and friction manufacturers. As issues arise during the Application development, engineers devise countermeasures that often entail new engineering techniques and methods. Sometimes, such countermeasures amount to inventions to cover the inadequacy of lining behavior during brake integration.

The ISO TC22/SWG2 - Brake Lining Committee established a task force to determine and analyze root causes for variability during dynamometer brake performance testing. SAE paper 2010-01-1697 “Brake Dynamometer Test Variability - Analysis of Root Causes” [1] presents the findings from the phases 1 and 2 of the “Test Variability Project.” The task force was created to address the issue of test variability and to establish possible ways to improve test-to-test and lab-to-lab correlation. This paper presents the findings from phase 3 of this effort-description of factors influencing test variability based on DOE study. This phase concentrated on both qualitative and quantitative description of the factors influencing friction coefficient measurements during dynamometer testing.

One of the most important means used for suppressing squeal noise in disc brakes is the application of shims on the pad backplates. In many cases this proves a very efficient tool depending on the type of shim applied in the specific cases. Building up knowledge on the effects of shims have been ongoing for several years, and measuring the important parameters characterizing the shims is crucial for understanding how to develop and implement the shims in an optimal way. Several methods are described in literature for measuring the constrained layer damping effect and one method is described for direct measurement of the shear stiffness and shear damping properties. However, up to now no method has been available that can measure and characterize the normal stiffness and damping properties of shims. This is one of the most important properties of shims as it controls the de-coupling effect in the direction of the normal forces.

Modern project management including brake testing includes the exchange of reliable results from different sources and different locations. The ISO TC22/SWG2-Brake Lining Committee established a task force led by Ford Motor Co. to determine and analyze root causes for variability during dynamometer brake performance testing. The overall goal was to provide guidelines on how to reduce variability and how to improve correlation between dynamometer and vehicle test results. This collaborative accuracy study used the ISO 26867 Friction behavior assessment for automotive brake systems. Future efforts of the ISO task force will address NVH and vehicle-level tests. This paper corresponds to the first two phases of the project regarding performance brake dynamometer testing and presents results, findings and conclusions regarding repeatability (within-lab) and reproducibility (between-labs) from different laboratories and different brake dynamometers.

This paper reports the progress that has been made to date on a research program that has as its focus to describe the mechanism of metal pick-up generation on passenger car disc brake pads in correlation with deep rotor scoring. In contrast to other existing generation theories, the new investigation considers other aspects of the initial onset of the metal pick-up.

In the past, each noise shim supplier had its own specifications to describe the properties of their noise shims (often also called as shim or damping shim). Due to that, it was difficult to compare the physical properties of noise shims from different suppliers. The main task was to define common specifications for daily quality/development tests. Traceability in prototype status and production was introduced establishing a clear declaration of noise shim deliveries with batch no. and “use by” date. Harmonization was created through standardized tests and procedures. In addition, a common noise shim database for all noise shim manufacturers was established. A more realistic compressibility test was developed to estimate the additional compressibility of noise shims based on bare pads under cold and hot conditions. These values are important to describe the axial decoupling at low pressure and the maximal displacement at high forces.

Electrically Powered Hydraulic Steering (EPHS) was developed in the early 90s and previously applied to vehicle segments B and C (small and medium-sized passenger cars). Till now more than 10 million vehicles are in the field. The advantages consist of the well known power density coming along with the flexible package. Value is added due to the consequent development and usage of electronic control realized in compact physical units. As a result key features for chassis control systems like controllability, high dynamic performance, and low energy consumption are achieved while maintaining mature and robust hydraulic components. Recent market requirements in other segments, e.g. Sport Utility Vehicles (SUV) and Light Commercial Vehicles (LCV) require higher powered motor pump units and lead to the decision to develop products in this direction.

The intent of this study was to compare the neck responses measured from the Hybrid III 3 and 6-year-old ATDs in laboratory testing to injuries sustained by three children in a field crash and investigate the appropriateness of recommended in-position neck injury assessment reference values (IARVs), and the regulated out-of-position (OOP) IARVs specified in FMVSS 208 for the Hybrid III 3 and 6-year-old ATDs. This paper principally reports on apparent artifacts associated with the Hybrid III 3 and 6-year-old ATDs, which complicated investigating the appropriateness of the in-position and out-of-position neck IARVs. In tests using 3-point belt restraints, these apparent artifacts included: 1) High neck extension moments, which produced the peak Nij values, without significant observed relative head-to-neck motion, 2) Neck tension forces well in excess of the IARVs that occurred when the ATD's chin contacted the chest.

The HYGE impact simulator is designed to reproduce the crash pulse of a real world vehicle impact in the laboratory environment. When a crash pulse is given, it usually takes a substantial amount of works and costs to adjust operating parameters to create the desired pulse on the HYGE machine. To save the operational cost, a mathematical model of the impact simulator using Ordinary Differential Equations (ODE's) was established in the early 70's by Milan and Hegel1. This ODE modeling method provides predictions of the crash pulses generated by the HYGE impact simulator. However, during subsequent years of practice, it has been found that in some cases these predictions are inaccurate. It is because the ODE method over-simplifies the physics. To improve the prediction accuracy, more sophisticated model of the physical process must be developed. The Fluid-Structure Coupled (FSC) modeling technique was applied on this dynamics problem of the HYGE impact simulator output prediction.

Steer-By-Wire will be the steering technology of the future. The mechanical connection between the hand wheel and the front axle will become obsolete. Independent electronically controlled actuators will set the road wheel steering angles and will provide force feedback to the driver. This paper presents the approach to establish a production intended steer-by-wire solution in two steps. In a first step a fail safe steer-by-wire system with a mechanical backup is developed which meets the functional and performance requirements of today's passenger vehicles. In the second step this concept is expanded to a future fault tolerant system architecture without any mechanical backup.

This paper reports the progress that has been made to date on a research program that has as its focus extracting the full spectrum of friction material performance. In contrast to existing friction test specifications, the new program considers the rise of coefficient of friction at each application by using a statistical evaluation. The statistical evaluation allows also a batch to batch control by monitoring statistical values.

This paper provides measurement and analysis on rotor in-plane mode induced squeal. Methodology is presented to simultaneously acquire both temporal and spatial squeal operational deflection shapes (ODS). Rotor accelerations both in the in-plane and out-of-plane directions were measured during squeal along with rotor's normal ODS using a laser vibrometer. Modal measurement and analysis of the rotor and pad in the in-plane and out-of-plane directions were conducted as installed in system condition. The test results indicating rotor modal coupling in the in-plane are provided, and out-of-plane directions, and conclusions on in-plane mode induced squeal are proposed. In addition, the countermeasure for squeal reduction is discussed.

Today's newer friction materials and brake systems are able to operate under extreme conditions that are not normally evaluated with the standard squeal rig procedures. This could cause some discrepancy between the squeal rig test results and the vehicle test results like Los Angeles City Traffic Test (LACT). In some cases the noise behavior of brake systems could change dramatically and take us by surprise with new squeal frequencies being uncovered or get flagged due to high occurrences. This discrepancy could also be a major handicap with respect to developing a noise fix in the lab if the squeal cannot be reproduced. In this paper, we evaluated some case studies where some extreme conditionings especially related to thermal inputs drastically changed the squeal behavior of the brake system.

Injuries to the knee-thigh-hip (KTH) complex in frontal motor vehicle crashes are of substantial concern because of their frequency and potential to result in long-term disability. Current frontal impact Anthropometric Test Dummies (ATDs) have been shown to respond differently than human cadavers under frontal knee impact loading and consequently current ATDs (and FE models thereof) may lack the biofidelity needed to predict the incidence of knee, thigh, and hip injuries in frontal crashes. These concerns demand an efficient and biofidelic tool to evaluate the occurrence of injuries as a result of KTH loading in frontal crashes. The MADYMO human finite element (FE) model was therefore adapted to simulate bone deformation, articulating joints and soft tissue behavior in the KTH complex.

Interaction of the human arm and deploying airbag has been studied in the laboratory using post mortem human subjects (PMHS). These studies have shown how arm position on the steering wheel and proximity to the airbag prior to deployment can influence the risk of forearm bone fractures. Most of these studies used older driver airbag modules that have been supplanted by advanced airbag technology. In addition, new numerical human body models have been developed to complement, and possibly replace, the human testing needed to evaluate new airbag technology. The objective of this study is to use a finite element-based numerical (MADYMO) model, representing the human arm, to evaluate the effects of advanced driver airbag parameters on the injury potential to the bones of the forearm. The paper shows how the model is correlated to Average Distal Forearm Speed (ADFS) and arm kinematics from two PMHS tests.

Electrically powered hydraulic steering systems (EPHS) are in mass production for about 6 years. They have been and still are very successful in the market as they follow the trend of supplying fully assembled and tested steering modules and the increasing demand for engine independent electrically powered systems. This paper illustrates the latest results of research and development in this sector leading to a new EPHS generation.

Injuries of the Occipitoatlantoaxial (Occ-C2) region (also known as atlanto-occipital injuries) are the most common form of cervical injury in children aged ten years and younger. The crash studied in this paper is unique in that there were three children ages 3, 6 and 7 involved in a frontal crash with a delta V of 28mph with each child receiving a nonfatal Occ-C2 injury of varying degrees. The 3 and 6 year-old children were remarkably similar in height and weight to the 3 and 6 year-old Hybrid III ATD's. Also, unique to this case is the fact that the right rear 6 year-old occupant likely sustained an Occ-C2 injury prior to impact with the frame of the front passenger seat. This crash environment was recreated utilizing MADYMO occupant simulation software. The models for the Hybrid III 3 and 6 year-old ATDs were used to represent the occupants in this crash.