Abstract：Based on the elastic beam theory, the failure mechanism of hierarchical corrugated structure with a second order core under local failure defects was studied. Firstly, through the force analysis of the original structural system of the hierarchical corrugated structure with a second order core and the structural system under local failure defects, six failure mechanisms of the structure are obtained, and the corresponding nominal force expressions of each failure mechanism are given.?Then the failure mechanism diagram was drawn according to the dominant relationship between the failure mechanism. The influence of parameter l1/l、θ and α on the failure mechanism diagram was discussed. at the same time, taking the corresponding nominal force of each failure mechanism as the constraint condition and minimizing the amount of structural materials (relative density) as the optimization objective, the structure lightweight optimization formula is given according to the optimization design of specific failure sequences.?Finally, some numerical simulations and experiments are given to verify the correctness of the failure prediction of the corrugated hierarchical structure with a second order core after local failure and the feasibility of the design of the hierarchical failure sequence. It is found that the change of different parameters will lead to different failure modes of the structure, and the occurrence of the failure mode on the secondary transfer path member of the hierarchical corrugated structure can not necessarily be used as the failure criterion of the structure. only when the structural failure mode appears on the main transfer path member, the failure mode can be used as the failure criterion of the structure, and the hierarchical corrugated structure can be used as the failure criterion of the structure according to the loss caused by the occurrence of each failure mode. It can be obtained that the relatively benign failure transfer path sequence of the structure is as follows: the first secondary transfer path component failure, and then the main transfer path component failure. The results of this paper can accurately grasp the change law of hierarchical corrugated structure system and the structural failure mechanism under local failure defects, and provide theoretical value for engineering application.
2021, Vol. 42 
