A-type frame fatigue life estimation of a mining dump truck based on modal stress recovery method

Cracks of A-type frame of a mining dump truck have occurred before exceeding structural fatigue design life. In order to accurately predict location of cracks and fatigue life of this component and find the reasons, a fatigue life analysis method combined with experiment and simulation is presented. Compared with the tested peak stress and simulated maximum stress of A-type frame under full loadings, the difference is acceptable so that the accuracy of finite element model of A-type frame is guaranteed. The rigid and flexible hybrid model of whole truck is built to get the stress situation based on modal stress recovery method, taking flexible body of A-type frame into account. Compared with the tested acceleration, the vertical simulated acceleration of the seat is acceptable, which ensures the validity of rigid and flexible hybrid model of this mining dump truck. According to the linear Palmgren–Miner hypothesis and S–N curve, fatigue life of A-type frame is assessed. The results show that the predicted cracks location and fatigue life of A-type frame is well accordance with the practical situation. To extend life of A-type frame, a modified structure is presented in this paper.