Critical evaluation of stress/strain estimation methods for fatigue life prediction of an automotive structural component

摘要

The stress and strain histories of two different designs of lower control arms (LCAs) under chuckhole loads are obtained by elastic-plastic finite element analysis and two stress-strain estimation methods based on elastic finite element analysis.Based on the stress and strain histories, the fatigue analysis indicates that the predicted fatigue life of the new design of the LCA is longer than that of the old design of the LCA because of the reduced stress concentration near the smaller centralhole in the new LCA. Two well-known stress-strain estimation methods, Neuber's method and the equivalent strain energy method, are critically evaluated by comparing the estimated stresses and strains with those obtained by the elastic-plastic finiteelement analysis in the critical region of the LCAs under plastic deformation.