异常荷载下导弹（火箭）级间连接结构失效分析

依据导弹（火箭）级间螺栓法兰连接结构特点，简化制作两组原理性实验件，设计进行了横向冲击和准静态荷载两种工况作用下连接结构失效实验。通过对比两种加载速率下的破坏结果，分析冲击力、加载力、螺栓响应数据和连接界面开缝位移数据，总结了连接结构的失效机理。此外，建立了针对连接结构失效进程仿真的有限元模型，并通过实测数据对其检验校核。研究结果表明：连接结构在横向异常荷载作用下呈序列失效特点，单个螺栓由于法兰盘“杠杆效应“存在明显弯曲变形，实际失效模式为“拉弯耦合”失效；冲击加载下螺栓材料“应变率效应”不显著，在本构模型的选择上可暂时不考虑动态加载的“应变率效应”；与实测数据对比可见，基于Abaqus显式算法的仿真模型，对连接结构失效进程的模拟误差在15%以内，工程中可以认为数值仿真得出的结论是可靠的。

Research on the Failure of Bolted Flange Connection Structure between Stages of the Missiles (Rockets) under the AbnormalLoad

According to the structural characteristics of the bolted flange connection structure between stages of the missiles (rockets), two sets of simplified principle test specimens were manufactured, and the failure experiments of connection structure under impact and quasi-static loads were designed and carried out. The response data of bolts and the slotted displacement of connecting interface are analyzed by comparing the failure results under the action of impact force and quasi-static loading force, and the failure mechanism of connection structure is summarized. A finite element model is established to stimulate the failure process of connection structure, which is verified by the measured data. The research results indicate that the connection structure shows a sequential failure mode under the transverse abnormal load, and the actual failure mode of single bolt is “stretching-bending coupling” failure due to the obvious bending deformation caused by the “leverage effect” of flange. The “strain rate effect” of bolt material under impact loading is not significant, and the “strain rate effect” of dynamic loading can be temporarily ignored in the choice of constitutive model in simulation. It can be seen from the comparison with the measured data that the simulation model based on the explicit algorithm of Abaqus has the simulation error of failure process of connection structure within 15%, and the conclusion obtained by the numerical simulation can be considered to be reliable in the engineering. Key