大型爆炸防护结构的动态应力测试与分析

Dynamic stress measurement of a large explosion-containment vessel

对某大型爆炸防护结构进行不同工况的爆炸实验,通过电测法测量了几个典型位置的应力,结果显示:从第1和第2主应力测试结果来看,球壳表面在爆炸冲击作用下的冲击应力峰值除第1次最大外,之后基本以拉压应力状态来回振动,而且振动应力在经过1～2个来回后立刻减小到100MPa以下,土的堆压可以起到削弱球壳振动的作用,因此球壳单次爆炸引起的振动疲劳问题大为削弱;模型的强度满足设计要求;排气孔附近是应力最为集中区域;炸药的形状系数对结构的安全影响很大。

Loading experiments were carried out in a large explosion chamber under different conditions, and the strains and stresses at several typical positions were measured by an electric test method. The experimental results show that： （1） The stress peak for the first time is the highest at the outer surface of the spherical shell under explosion impact, and then the vibration is basically dominated in the states of alternate tensile and compressive stresses, which fall below 100 MPa immediately just after 1-2 cycles, so the vibration fatigue of the spherical shell can be markedly weakened by the soil accumulation; （2） The strength of the model meets the design requirements; （4） The area showing the maximum stress concentration is nearby the discharge port; （4） The shape factor of the explosive charge has a great influence to the structure safety.