Failure mode analysis and validation of hierarchical sandwich structures under compression

Abstract

Based on the elastic thin plate theory, the mechanical properties and failure pattern are studied, considering the local failure defects, and the nominal positive stress expression of the hierarchical sandwich structures with a second-order core were presented. Moreover, the dominant relationship of each failure mode was compared, and the structure failure mechanism diagram is constructed by MATLAB, then the influence law of different local failure defects on the structure-dominant failure mode was discussed. However, for the failure mode of the structure, the emergence of the dominant failure mode of the secondary transmission path component may not be used as the failure criterion of the structure. Only when the failure mode of the structure appears on the main transmission path components, the failure mode can be used as the failure criterion of the hierarchical sandwich structure with a second-order core. In the failure mechanism diagram of the hierarchical sandwich structure with a second-order core, the single dominant failure mode of the structure can be accurately predicted, and for the junction of multiple mixed dominant failure modes, the structure is more prone to structural/component stability failure. At the same time, in order to test the correctness of the theoretical prediction, the verification experiment models were made with photosensitive resin 9000 material and 3D printing technology. Through the uniaxial compression test on the experimental model and numerical simulation, the correctness of the theoretical prediction of structural failure mode and ultimate bearing capacity is verified. The results show that the failure mode of the structure can be accurately predicted by the theoretical analysis, and the relative error is about 20% when calculating the bearing capacity. The experimental and simulation results agree well with the theoretical prediction.