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.

Prediction of fatigue life and estimation of its reliability on the parts of an air suspension system

“…Consequently, an evaluation of the component's life cycle is required from the initial design stage. In particular, studies using a computational model to estimate component fatigue have been actively developed because of the low cost and time savings associated with the estimation (Yim and Lee, 1996;Lee et al, 2000;Yoo and Haug, 1986;Kim et al, 2002;Jung et al, 2005). Also, an evaluation of the reliability of the expected fatigue life using an experimental design has been investigated (Hahn and Shaprio, 1967;Seo, 2001).…”

“…To estimate fatigue life, the required Dynamic Stress Time History (DSTH) can be calculated using a flexible body dynamics analysis and the Modal Stress Recovery (MSR) method (Yoo and Haug, 1986;Jung et al, 2005). To evaluate the reliability of the fatigue life estimate using the S-N method, the fatigue life curve is selected as a random variable.…”

Dynamic Analysis of an Automobile Lower Suspension Arm Using Experiment and Numerical Technique

“…Hosseini et al (2007) performed experimental modal analysis of crankshaft to validate the numerical results. In particular, studies using a computational model to estimate component fatigue have been actively developed because of the low cost and time savings associated with the estimation (Yim & Lee, 1996;Lee et al, 2000;Kim et al, 2002;Jung et al, 2005). Recently, Choi et al www.intechopen.com (2007) used the damage index method to localize and estimate the severity of damage within a structure using a limited number of modal parameters for steel plate girder and other highway bridges.…”