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Estimation and prediction of residual life and reliability are serious concerns in life cycle management for aging structures. Laboratory testing replicating fatigue loading for a typical military aircraft wing skin was undertaken. Specimens were tested until their fatigue life expended reached 100% of the component fatigue life. Then, scanning electron microscopy was used to quantify the size and location of fatigue cracks within the high stress regions of simulated fastener holes. Distributions for crack size, nearest neighbor distances, and spatial location were characterized statistically in order to estimate residual life and to provide input for life cycle management. Insights into crack initiation and growth are also provided.

As global automobile manufacturers prepare for the phase-out of R134a in Europe, they must address the issue of using the new refrigerant for European sales only or launching the product worldwide. Several factors play into this decision, including cost, service, risk, customer satisfaction, capacity, efficiency, etc. This research effort addresses the minimal vehicle-level hardware differences necessary to provide a European solution of R1234yf while continuing to install R134a into vehicles for the rest of the world. It is anticipated that the same compressor, lubricant and condenser; most fluid transport lines; and in most cases the evaporator can be common between the two systems.

A coupled vibration and pressure loading procedure has been developed to perform a CAE virtual test for engine air intake manifolds. The CAE virtual test simulates the same physical test configuration and environments, such as the base acceleration vibration excitation and pressure pulsation loads, as well as temperature conditions, for design validation (DV) test of air intake manifolds. The original vibration and pressure load data, measured with respect to the engine speed rpm, are first converted to their respective vibration and pressure power spectrum density (PSD) profiles in frequency domain, based on the duty cycle specification. The final accelerated vibration excitation and pressure PSD load profiles for design validation are derived based on the key life test (KLT) duration and reliability requirements, using the equivalent fatigue damage technique.

Modern automobiles utilize stabilizer bars to increase vehicle roll stiffness. Stabilizer bars are laterally mounted torsional springs which resist vertical displacement of the wheels relative to one another. A stabilizer bar is constructed in such a way that it will meet package constraints and fatigue requirements. In order to design a robust stabilizer bar, Taguchi's “Design of Experiment method” is used. The objective of this paper is to develop a robust stabilizer bar design that will maximize the fatigue life and the roll stiffness while minimizing weight. This study is based on results obtained by CAE analysis.

Plastic air induction system (AIS) has been widely used in vehicle powertrain applications for reduced weight, cost, and improved engine performance. Physical design validation (DV) tests of an AIS, as to meet durability and reliability requirements, are usually conducted by employing the frequency domain vibration tests, either sine sweep or random vibration excitations, with a temperature cycling range typically from -40°C to 120°C. It is well known that under high vibration loading and large temperature range, the plastic components of the AIS demonstrate much higher nonlinear response behaviors as compared with metal products. In order to implement a virtual test for plastic AIS products, a practical procedure to model a nonlinear system and to simulate the frequency response of the system, is crucial. The challenge is to model the plastic AIS assembly as a function of loads and temperatures, and to evaluate the dynamic response and fatigue life in frequency domain as well.

Evaporators for automotive air-conditioning systems are being coated externally to improve corrosion resistance, water drainage, and reduce potential odor concerns. The coating durability and efficiency in achieving its corrosion resistance depends on the coating uniformity and adhesion characteristics. Good coating adhesion on aluminum surface can be achieved after freeing the surface from the oxide and flux residues. Evaporators manufactured by the Controlled Atmosphere Brazing (CAB) process have flux residue remaining on the surface, the presence of which interferes with the coating process and also affects the performance of coated components. A methodology to quantify the effect of high Nocolok flux residue on heat exchanger coating uniformity has been presented.

There are benefits of using ultra thin wall (UTW) substrates (i.e., 900/2, 400/4, etc) in lowering cost and emission level. However, the more fragile mechanical characteristics of the UTW present a challenge to design and manufacture of robust catalytic converters. This paper describes a method of canning trial, where a combined Design of Experiment / Monte-Carlo analysis method was used, to develop and validate a canning method for ultra thin wall substrates. Canning trials were conducted in two stages-- Prototype Canning Trial and Production Canning Trial. In Prototype Canning Trial, the root cause of substrate failure was identified and a model for predicting substrate failure was established. Key factors affecting scrap rate and gap capability were identified and predictions were performed on scrap rate and gap capability with the allowed variations in the key factors. The results provided guidelines in designing production line and process control.

This paper describes two electronic throttle controllers of Visteon Corporation with one already in production and the other currently under development. Analysis and tuning of the two controllers are described. The general structure of the controllers consists of a reference shaping subsystem and a proportional-plus-integral-plus-derivative(PID) controller supplemented with additional terms that deal with the nonlinearility of the electronic throttle body. Due to a friction cancellation term in the controller that minimizes the nonlinearity of the system, linear system analysis techniques are applied. The transfer functions of the electronic throttle body at six different operating conditions are derived. Analysis of the closed-loop dynamics is performed based on the plant and the controller transfer-functions. Controller fine-tuning is performed using frequency response techniques, MATLAB simulations and testing on the actual system.

In Brazil the market for plastic parts molds, in last few years had become very competitive, with several Vehicle Operations and a big number of a different models, and with today total market volume it means low volumes productions for each model. This market demands for good toolshops and at the same time a big pressure to reduce investments, one of the most important. Plastic components usage in the car, is increasing overtime, with new applications for Exterior, interior and powertrain, requiring new technologies for Injection molding processing and making molds to be more complex. The development of plastic parts in Brazil has its own characteristics, strengths and weaknesses. In fact a big and heterogeneous market. This paper intends to present an analysis of development of plastic parts in Brazil, considering the development of mold tooling locally, focusing the automotive market.

Automotive gear oil development has expanded beyond the historical requirements of emphasizing wear protection to encompass modern needs for fuel economy and limited slip frictional properties. This paper describes the development process of a new generation, fuel efficient gear lubricant for use in light duty vehicles. A systematic formulation approach was used, encompassing fluid viscometrics and additive optimization. Performance testing in both laboratory and vehicle tests is described. Though standard GL-5 tests were used to confirm oxidation, wear and corrosion performance, emphasis is given to those methods used for optimizing fuel economy.

Evolutionary Operation (EVOP) experimental design using Sequential Simplex method is an effective and robust means for determining the ideal process parameter (factor) settings to achieve optimum output (response) results. EVOP is the methodology of using on-line experimental design. Small perturbations to the process are made within allowable control plan limits, to minimize any product quality issues while obtaining information for improvement on the process. It is often the case in high volume production where issues exist, however off-line experimentation is not an option due to production time, the threat of quality issues and costs. EVOP leverages production time to arrive at the optimum solution while continuing to process saleable product, thus substantially reducing the cost of the analysis.

A major part of product development is to validate robustness to the environment (e.g. temperature, vibration, EMC). Although much time and expense is spent doing so, using traditional approaches often leads to “feel good” results since the product “passes”. Such a false sense of security is misleading since such validation methods can have serious deficiencies. Presented is a Design Assurance process (Accelerated Stress Assurance Plan - ASAP) to validate modules that addresses these deficiencies. It places major emphasis on the analysis and development stages. It does not require large sample sizes, and overall test time and facilities is reduced (30-50% possible).. Just as for electronic modules, new and major changes to IC's need a shorter validation process. As an example, a relatively fast procedure for the production and application release of improved molding compounds for IC's is presented.

Visteon has developed a CAE procedure to qualify plastic door trim assemblies under the vehicle door slam Key Life Test (KLT) environments. The CAE Virtual Door Slam Test (VDST) procedure simulates the environment of a whole door structural assembly, as a hinged in-vehicle door slam configuration. It predicts the durability life of a plastic door trim sub-assembly, in terms of the number of slam cycles, based on the simulated stresses and plastic material fatigue damage model, at each critical location. The basic theory, FEA methods and techniques employed by the VDST procedure are briefly described in this paper. Door trim project examples are presented to illustrate the practical applications and their results, as well as the correlation with the physical door slam KLTs.

1.0 During the warm up process of the coolant in automotive heater systems physical properties such as the density, dynamic viscosity, kinematic viscosity, specific heat and thermal conductivity vary with temperature. To conduct any heater analysis, therefore, it is essential that such variations with temperatures be evaluated. In the present paper a comprehensive literature search is conducted for the published physical properties of the automotive coolants ethylene glycol and propylene glycol. The data are analyzed and compared, and equations describing the variation of the above named physical properties with temperature are derived and presented. The effect of the temperature on the internal heat transfer coefficient is discussed. A comparison of the heat transfer performance between the two glycol coolants is presented. The temperature range studied extends from - 35 to at least 125 degree Celsius.