Failure evolution analysis of end-plate connection joint based on structural stressing state theory

Based on the structural stressing state theory, the structural behavior of four extended end-plate joints under cyclic loading was analyzed to visualize their operational performance and failure evolution. The experimental strain data are modeled as generalized strain energy density (GSED) to characterize the structural stressing state and the corresponding characteristic parameters, and the Mann-Kendall (M − K) criterion is coined to determine the critical loads (P and Q) of the M_j−E_j curves of the joints and derive the starting point of structural continuity damage. Then, the trend of the joint stressing state curves before and after the critical load is reflected by analyzing the parameters of the working state of the joint (hysteresis performance, strain distribution mode at key measurement points, bending and shear deformation development, bolt force and prying force). Finally, the sample point expansion (SPE) method is introduced to effectively extend the joint experimental data, visualize the change process of strain/stress field, and reveal the mechanical response mechanism and evolutionary degradation law behind it in depth. The results of the study provide a new perspective for conducting nodal analysis and a reference for failure analysis of end-plate connection structures.