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Although computer models for vehicle and sub-system performance simulations have been developed and used extensively in the past several decades, there is currently a need to enhance the overall availability of these types of tools. Increasing demands on vehicle performance targets have intensified the need to obtain rapid feedback on the effects of vehicle modifications throughout the entire development cycle. At the same time, evolution of the PC and development of Web-based applications have contributed to the availability, accessibility, and user-friendliness of sophisticated computer analysis. Web engineering is an ideal approach in supporting globalization and is a cost-effective design-analysis integration business strategy. There is little doubt that this new approach will have positive impacts on product cost, quality, and development cycle time. This paper will show how Microsoft Excel and the Web can be powerful and effective tools in the development process.

This document applies to webbing used on occupant restraint systems in service on 14 CFR/CS part 23, part 25, part 27, and part 29 aircraft applications. The guidelines presented within this document are intended to be supplemental to the requirements supplied by the OEM in the CMM, ICA, or like document. In cases of conflict between this ARP and the OEM’s requirements, the requirements of the OEM shall be followed. The objective of this document is to establish practical guidelines to help operators in the determining if restraint webbing has reached the end of its service life. The recommendations contained herein are based on test data from in service restraint systems and the continued airworthiness guidelines recommended by restraint system OEMs.

The annual energy potential of a wind site cannot be estimated with the commonly available average wind speed data. It rather involves a detailed knowledge of the probability distribution and a complex computation of its cubic power integral over the year. A site with lower average wind speed can have higher energy potential if the speed distribution is flatter. The wind speed variation with time can be accurately represented by the Weibull probability distribution function, which can be approximated by the Raleigh distribution. Since wind power has the cubic relation with the speed, the concept of the root-mean-cube (RMC) speed is defined and developed in the paper. All sites having the same RMC speed would have the same annual energy potential. An analytical expression has been derived that relates the RMC speed with the average speed. It allows a quick and easy determination of the annual energy potential by using the commonly available average wind speed data.

Design of suspension systems for Heavy Trucks is always challenging due to the heavy loads the system is exposed to and the long life requirements for the total system. Historical solutions were over designed structures to get the needed life and reliability. This always meant heavier parts. In today's economy, the vehicle weight of commercial heavy trucks is a very important feature for our customers and the end user. Lighter, well-designed suspension components provide better ride quality to the drivers through lower un-sprung weight, lower initial costs and greater payloads. The latest available structural optimization techniques are a business requirement for tomorrow's products. This paper describes the developed methodology used by DANA Engineers to design a weight optimized upper control arm for Commercial Heavy Trucks in step by step fashion. The method starts with determining the loads on the component part.

This paper deals with a Valeo proposal to reduce the weight of the front end carrier, especially in the case of steel carrier, whose weight can reach 8 to 10 kg. The technology proposed by Valeo is a sandwich material made of two steel layers and one polymer layer in the middle, developed by Arcelor, a steel supplier. What will be highlighted in this document is the application of this technology to an existing front end carrier design. First of all, static simulations are performed to evaluate the potential weight reduction. Parts stamped with serial tools are manufactured and tested. Correlation with simulation is then performed to confirm the weight saving. This Valeo solution allows a weight reduction of at least 15 % compared to an all-steel carrier.

The motion of vehicles over rough pavement induces random variable stresses in their structures, that may cause fail by fatigue. Fatigue lifetime estimation is a phenomena with great levels of variability, and it may adequately treated through reliability methods, in terms of fail probability or reliability indexes. In this work, a procedure for optimization considering discrete design variables is applied in weight optimization of a mini baja structure, with reliability-based design constrain. The lifetime estimation is based in time-domain approach, using “stress levels vs. Number of cycles” curves, the Palmgreen-Miner Rule to compute the cumulative damage and the Rainflow Method for cycles counting. First Order Reliability Method (FORM) and Monte Carlo Simulation with Importance and Adaptive Sampling are used to evaluate the reliability index.

An important emerging technical area is computer-based modeling of the various manufacturing processes that are used in many diverse industries. These models are used to optimize manufacturing techniques to reduce fabrication costs and improve the service performance. One manufacturing process important in steel fabrication is welding. It can be a useful tool to aid in reducing fabrication costs and service durability by optimizing the weld process and is the subject of this paper.

Discussed in this paper are the aerodynamic features of the Western Michigan University Gamma passenger vehicle. The vehicle was designed and constructed for the 1980 Sea-to-Sea Econorallye II. Incorporated in the design were aerodynamic modifications, with special emphasis on front and rear body shapes. The main objective of the aerodynamic modifications was to reduce the drag coefficient of the vehicle. Methods of analysis were scale model wind tunnel testing and coastdown testing. A series of wind tunnel tests were performed with a 1/15th scale detailed model of the prototype. The forces which contribute to the resistance of the motion are discussed. Wind tunnel philosophy, techniques, and assumptions are also discussed. Coastdown tests were performed to determine the drag as measured on the road. The drag coefficient was determined by statistical analysis of the test data.

Wet clutches drag loss simulation is essentially linked to the clutch friction surface patterns in addition to the main geometry and conditions of the interface (relative speed, separation, inner and outer radius, viscosity and boundary pressures). The clutch patterns promote cooling flow and micro-hydrodynamic effects to aid clutch separation but greatly complicate the simulation of drag loss during separation. These drag losses are important in understanding the system losses as well as finding the most effective clutch cooling strategy. Typical clutch models either only consider simple patterns, such as radial grooves, or require significant simulation efforts to evaluate. Additionally, many simple models require calibration to measurement of the actual clutch they try to model before they provide a useful model.

Abstract Car manufacturers are continuously improving passenger comfort by advancing technologies including highly automated driving. Before the broad introduction of automated driving, specific human factors regarding passenger comfort must be considered, including motion sickness. Therefore, the identification of the frequency of motion sickness and associated factors in the population is needed to extrapolate the effects for future mobility systems. We conducted three surveys between 2015 and 2020, asking people questions about their experience with motion sickness in cars. Based on the responses of 1165 participants, gender and age showed a strong influence on the self-reported frequency of motion sickness. For deeper analysis, a logistic order regression model was used to estimate the frequency of motion sickness for different user typologies.

A brief description of part creation on the computer by solids is presented. The capabilities, use, and benefits of this method in the product development cycle is given. Solid modeling as the basis for downstream C A E work and specific examples are discussed.

Given the myriad of testing options available and the reams of testing specifications that exist today, how do you know what testing process should be used for a given component or system? What information is needed and what is the most efficient means of getting the desired results. This paper compares two accelerated testing methods with more traditional validation tools and examines the relationship between the information goals, the process used, the anticipated failure modes, and the equipment needed. A decision making algorithm will be proposed.

The automotive PowerNet is in the middle of a major transformation. The main drivers are steadily increasing power demand, availability requirements, and complexity and cost. These factors result in a wide variety of possible future PowerNet topologies. The increasing power demand is, among other factors, caused by the progressive electrification of formerly mechanical components and a constantly increasing number of comfort and safety loads. This leads to a steady increase in installed electrical power. X-by-wire systems1 and autonomous driving functions result in higher availability requirements. As a result, the power supply of all safety-critical loads must always be kept sufficiently stable. To reduce costs and increase reliability, the car manufacturers aim to reduce the complexity of the PowerNet system, including the wiring harness and the controller network. The wiring harness e.g., is currently one of the most expensive parts of modern cars.

This design oriented paper provides an introduction to the fracture mechanics parameters controlling below-yield-strength fractures and subcritical crack growth, due to either fatigue loading or environmental attack. Emphasis has been placed on those basic fracture control concepts, which can aid the designer in material selection, to prevent the above mentioned occurrences. The major concepts that have been outlined within the paper are: the elastic crack tip stress field and its magnitude as measured by the stress intensity factor, the relationship between the stress intensity factor and the material's fracture toughness, the small scale yield model and the plastic zone correction, the relationship between the range in the stress intensity factor and the rate of fatigue crack growth, and a quantitative measure of a material's resistance to environmental attack under static loading.

A vehicle converts kinetic energy in heat through the brake system during a typical braking action. The friction between the "brake pad" and the brake disk surface is the physical mechanism that allows this completion of work. The brake disk attached parts are thermally affected by this generated heat. The generated heat flows through the brake disk attached parts, which are thermally affected. The heat flow can negatively affect these parts, specifically, the wheel cover. This article shows a comparative study between numerical simulation and physical test about the brake disk, evaluating heat effect on the wheel cover. The physical test allows previewing damage by excess of temperature on the wheel cover on the road common use of the vehicle. A computational model was developed using commercial software to calculate temperatures in this part based on the physical test. All computational parameters were adjusted trying to fit the computational results with the test results.

Correct simulations of rotating wheels are essential for accurate aerodynamic investigations of passenger vehicles. Therefore, modern automotive wind tunnels are equipped with five-belt moving ground systems with wheel drive units (WDUs) connected to the underfloor balance. The pressure distribution on the exposed areas of the WDU belts results in undesired lift forces being measured which must be considered to obtain accurate lift values for the vehicle. This work investigates the parasitic WDU lift for various configurations of a crossover SUV using numerical simulations that have been correlated to wind tunnel data. Several parameters were considered in the investigation, such as WDU size, WDU placement, tyre variants and vehicle configurations. The results show that the parasitic lift is more sensitive to the width than the length of the WDU. However, the belt length is also important to consider, especially if the wheel cannot be placed centred.

Many different studies have been performed to understand brake roughness, and in particular how brake rotor Disc Thickness Variation (DTV) is generated. The intent of this paper is to analytically explore through non- linear finite element modeling methods the effects of wheel joint variables on brake rotor mounted Lateral RunOut (LRO). The phenomenon of LRO is believed to be a primary contributor to DTV generation and resulting brake roughness. CAE analyses were conducted in non-linear contact mechanics in which real contacts between components exist. Various joint designs were simulated to compare rotor LRO and coning. Several parameters inherent to the design of wheel joints were varied and studied. A comparative approach was used to develop specific design recommendations for LRO reductions.

This paper presents a nonlinear observer and controller based on passivity and sliding mode approach for vehicle traction control. The main contribution is the on-line estimation of the tire force which is needed for control. The concept of relaxation length describes the wheel-slip variation as a first order model. From this concept a differential equation of tire force is proposed to design a controller based on nonlinear observer. Only longitudinal dynamics are considered in this study. Stability analysis in closed-loop is proved by Lyapunov's method. Sufficient conditions for applying sliding mode based control are derived. The proposed control is verified through one-wheel simulation using “Magic formula” tire model. The robustness of control is tested by including errors in the parameters and by changing value of tire adhesion. A comparison of the proposed approach of control with PD control is given.

Abstract The key issues of automatic emergency braking (AEB) control algorithm are when and how to brake. This article proposes an AEB control algorithm that integrates risk perception (RP) and emergency braking characteristics of professional drivers for rear-end collision avoidance. Using the formulated RP by time to collision (TTC) and time headway (THW), the brake trigger time can be determined. Based on the professional driver fitting (PDF) characteristic, the brake pattern can be developed. Through MATLAB/Simulink simulation platform, the European New Car Assessment Programme (Euro-NCAP) test scenarios are used to verify the proposed control algorithm. The simulation results show that compared with the TTC control algorithm, PDF control algorithm, and the integrated PDF and TTC control algorithm, the proposed integrated PDF and RP control algorithm has the best performance, which can not only ensure safety and brake comfort, but also improve the road resource utilization rate.