A GENERALIZED LOCAL STRAIN APPROACH TO CONSIDERING THICKNESS EFFECT ON FATIGUE PERFORMANCE

摘要

Firstly stress concentration factors for single-edge-notch tension (SENT) specimens under different thickness-induced stress states are expressed in an explicit form by fitting the three-dimensional finite element analysis results. Then a generalized local strain approach is developed to incorporate this 'thickness effect'. Also machining technique influence factor is introduced to consider the specimen machining quality. Validation against calculation and fatigue test result for SENT specimen shows the calculation obtained by the proposed approach is in better agreement with experimental result than traditional prediction. Also the generalized local strain approach can be further applied to fatigue life prediction of other type specimens under different thickness-induced stress states.