The fatigue life estimation of a product having elasto-plastic behavior

The fatigue life estimation of a product having elasto-plastic behavior which results from preloading and holding of catch and strike has been studied through strain measurements and numerical calculations. The distributions of the plastic zones have been analyzed using finite element method and the loading history has been obtained through strain gage measurements of the different strike thickness and separation. The experimental measurements have been used as input load in the numerical analysis. It has been found that the plastic deformation region can be redesigned to reduce the stress concentrations by adjusting the tension limits and initial catch–strike separation for predetermined product service life.

► This work highlights a low cycle fatigue problem in the case of elongation.
► It shows elasto-plastic loading effect on the notched structure.
► The numerical and experimental methods were coupled for sensitive fatigue estimation.
► The plastic deformation of the hook can be redesigned to reduce stress concentrations.