Strength analysis and optimization of three-bridge rigid frame for mining dump truck using finite element stress linearization method

A finite element stress linearization method is introduced into the structural verification of the three-bridge rigid frame, a newly designed frame for the wide-body mining dump truck. This method successfully captures the potential local failure around the structural-discontinuity zone. The results indicate that the suspension supports experience high-level stress under six operating conditions and the most dangerous location of the frame always lies at the weld bead between the suspension support and frame. The stress intensities of the original frame under six operating conditions are all smaller than the allowable value, manifesting that the strength of the original frame can meet the strength requirements. The local modifications greatly reduce the local stress and thus improve the reliability of the frame, manifested by the reduced stress level and stress intensity along dangerous paths. The primary plus secondary stress intensity along the most dangerous path decreases by 16.69% under the condition of free-hanging left front wheel, and by 59.91% under the condition of free-hanging right rear wheel. The present work provides a sound method to evaluate the local failure of the frame for the mining dump truck containing many structural-discontinuity zones, and the result is helpful for the continuous improvement of the frame for the wide-body mining dump truck and provides a guideline for designing a new frame.