A METHOD TO DETERMINE THE SAFETY COEFFICIENT IN FATIGUE OF COMPRESSOR VALVES

摘要

This paper proposes a method of evaluating the fatigue life of a refrigeration compressor reed valve, given the applied stresses as might be computed by a valve simulation. Mean and alternating values of equivalent stresses (e.g. Von Mises) are plotted in the Haigh diagram. Various choices of models are considered for the safe area of the diagram. This method takes into account surface finish, thickness, ultimate tensile strength and residual stresses related to the strip valve material and process used to obtain the parts. For a given level of confidence, it is possible to predict a safety coefficient, the ratio between admissible stress and applied stress.