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An overstress testing methodology has been developed by Valeo Wiper Systems and followed in order to decrease the project validation time and determine the wiper system mechanism reliability. This methodology could be followed to analyze new projects, as well as quality problems, improvements ideas and to test new materials. The stress levels were calculated by using the cumulative fatigue laws. During the accelerated test the samples were tested until some component or function fail. In order to have representative results, all the failure modes shall be compared with the FEA (Finite Element Analysis) performed with the drawings. The main objective was to verify the possibilities of reliability increasing to have a robust product, and it was necessary to validate the product weak point. The reliability level is determined by using the Life Data Analysis methodology, acquiring the number of the wiping cycles performed until the failure.

Optimizing the wiper system performance motivates the design engineer to create a product as robust as possible against the occurrence of wipe defects related to vibratory phenomena between the rubber blade and the windshield. In some configurations, these vibrations generate visual or audible annoyance for the driver. These instabilities phenomena only appear under specific operating and environmental conditions characterized by windshield moisture and cleanness, contact pressure of the rubber blade on the glass, attack angle of the wiper blade on the windshield, component stiffness, windshield curvature etc. In the process of eliminating all potential instabilities, modeling the wiper system structures can contribute to understand its working dynamics. Therefore, a new computation tool is developed and validated by experimentation on a specific test bench.

An experimental investigation is first carried out to analyze the influence of the geometrical configuration of a wiper system on the chattering occurrence. The measurement results show a combined influence of the load applied on the rubber blade and the attack angle on the vibratory level of the blade. A mathematical four-degree of freedom model, based on the Sprag-slip theory, is developed to simulate the behavior of the rubber blade during the wiping motion. A dynamic analysis is then performed to define conditions for stable motion of the system. The comparison of these theoretical unstable configurations and the experimental chattering cases shows good correlation. This theoretical survey points out necessary conditions for unstable motion, in terms of orientation of the rubber blade to the glass surface.

Semi-solid metal forming processes are of large industrial interest for the production of various components. Reduction of macro-segregation, reduction of porosity, possibility of near net shape are the principal advantages over casting, forging and powder metallurgy techniques. This paper gives a brief description of the Thixomag® process applied to a AZ91D magnesium alloy. As it is well known, special material properties are required for the thixoforming process. It is especially necessary to homogenize the temperature along the billet during the induction reheating. This homogenization of temperature enables to avoid the coarsening of the primary solid phase and defects in the final part. To determine the optimum conditions and to reduce the process duration, numerical simulation has been used. A 2D model, where thermal and electromagnetic are coupled, was built.

The forming of alloys from the liquid state can be realized thanks to various casting technologies where the temperature of the metal is high enough to fill a given die correctly. A variety of casting defects often occur in the final part, such as gas porosity, shrinkage porosity and hot cracking. In the case of the magnesium foundry, all handling of molten metal requires serious safety precautions to avoid explosion and burning. Protective gas mixtures (SF6, SO2, CO2) are used to minimize the ignition risks but have a bad impact on the environment. The semi-solid forming operates using a lower temperature in the solidus-liquidus range and seems to be interesting, in particular, for the quality requests of the die caster and for safety and a clean environment. The purpose of this paper is to present the mechanical results of tensile tests carried out on magnesium standard samples, which are cast by Thixomag® process from the semi-solid state.

This paper presents the potential for rear closure submodules. Side door modules and lightweight rear closures have attracted a lot of attention in recent years. However the characteristics of future liftgates allow the design of specific mechatronic sub-modules (e-modulesTM). Beside structure, rear closures satisfy three main functions: rear vision, rear signaling and rear access. All are undergoing a generation change that will be outlined in the first part of this paper, system by system. Each time the rationale behind modular integration, whether electronic or mechanical, will be reviewed. The second part presents examples of e-modulesTM that illustrate the potential gains in terms of ease of assembly, packaging optimization and network integration.

For wiper systems, rubber-wiping elements are one of the key components ensuring excellent wipe quality and, therefore, satisfying driver visibility, security and comfort. In order to track the rubber element wear precisely and to know when the blades have to be changed, a wear indicator for the rubber element has been developed. The indicator is made of a black plastic material with an adhesive, pressure sensitive, backing located on the main bow. With time and external stresses, the sticker turns a green color at mid life, and yellow at the end of life. Yellow color indicates to the driver, the end of the effective life of the wiper blade.