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The reliability of engine valve springs is a very important issue from the point of view of warranty. This paper presents a combined experimental and statistical analysis for predicting the fatigue limit of high tensile engine valve spring material in the presence of non-metallic inclusions. Experimentally, Fatigue tests will be performed on valve springs of high strength material at different stress amplitudes. A model developed by Murakami and Endo, which is based on the fracture mechanics approach, Extreme value statistics (GUMBEL Distribution) and Weibull Distribution will be utilized for predicting the fatigue limit and the maximum inclusion size from field failures. The two approaches, experimental and theoretical, will assist in developing the S-N curve for high tensile valve spring material in the presence of non-metallic inclusions.

This paper discusses the design and application of a semi-active damping system controlled by a student designed microprocessor that reads accelerations laterally and longitudinally from separate accelerometers to anticipate chassis orientation and responds with an analog voltage to each damper. This dynamically alters the shock oils effective viscosity to keep the chassis movement within desired parameters. The system described will be incorporated into a one-seater open wheeled racecar that is outfitted with a non-parallel, unequal length SLA suspension designed for entry in the 2001 Formula SAE competition. The focus will be more on the damping of low and high frequency obstacles and the resulting chassis (sprung mass) control rather than controller design, since it is an entirely different collection of papers unto itself.

This paper discusses how to effectively design and set-up an ideal spring/damper combination in a low-mass open wheeled racecar to properly control vehicle handling and gain optimum performance of the system. The system that will be discussed is outfitted with a non-parallel, unequal length SLA suspension that was designed and raced at the 2001 Formula SAE competition. The focus of this paper will be more on how to choose an ideal suspension set-up for a low-mass open wheeled racecar, while considering the various variables that can affect the system as a whole. To properly design a suspension, a passive system will be used, and then the performance gains of a semi-active system will be introduced and discussed.