马场坪收费站汽车爆炸破坏的数值模拟分析

Numerical simulation for damage of Ma Chang Ping highway toll station under lorry-blasting

应用LS-DYNA有限元程序建立马场坪收费站在汽车爆炸作用下的数值计算模型,对空间网架结构在爆炸作用下的冲击波超压、破坏过程和破坏模式进行了数值模拟计算。提取网架结构内表面有限测点的爆炸冲击波超压并将其进行本征正交分解(POD),得到冲击波压力场的显性表达和主本征模态。对模拟计算结果与收费站实际破坏情况进行比较分析,揭示了空间网架结构的爆炸破坏机理和原因。数值结果表明,LS-DYNA非线性有限元模型与POD法的结合,能够准确地模拟空间网架结构在爆炸作用下的破坏过程和模式,充分泄爆可以防止空间网架结构在爆炸作用下的破坏倒塌,避免人员损伤。提出在空间网架结构的抗爆和防爆设计中,应采取"强结构弱围护"的设计原则。

A numerical simulation model for damage of Ma Chang Ping highway toll station under lorry-blasting was established by employing the FE fluid-structure coupling algorithm LS-DYNA. The shock wave overpressure, failure process and failure modes of the spatial truss structure subjected to explosion were numerically simulated. In order to get the explicit expression of shock wave pressure field and the principal eigenmodes, the blast overpressure data of finite points at the internal surface of the spatial truss structure were extracted and were decomposed with the proper orthogonal decomposition （POD） method. Through a comparative analysis between the simulation results and the actual destruction of the toll station, the failure mechanism and causes for the explosive damage of the spatial truss structure were revealed. The numerical results showed that LS-DYNA nonlinear finite element model combined with the POD method can accurately simutate the destruction process and damage models of the spatial truss structure under blast, and adequate venting can prevent the spatial truss structure under explosion from collapsing and can avoid people wounded. Finally, the design principle of strong structure and weak envelope was proposed for blast-resistant and explosion-proof of spatial truss structures.