A Study on the Fatigue Life Prediction of OHT Vehicle Structures Using the Modal Stress Recovery Method

Abstract

In this paper, a computer aided analysis method is proposed for a durability assessment in the early design stages using the Modal Stress Recovery (MSR) and the linear damage rule. From a dynamic analysis of the OHT vehicle system with some flexible bodies, modal displacement time histories of vehicle structure components are calculated. From finite element analysis of components, modal stresses are calculated. With the modal displacement time history and the modal stress of the component, the dynamic stress time history at the critical location is produced using the superposition principle. Using the linear damage rule and the cycle counting method, the fatigue life is predicted from the dynamic stress time history. The process of predicting the fatigue life using the proposed computer models in this paper may be applied to structures of various dynamic systems.