一种冲击波作用下结构毁伤算法研究

针对爆炸冲击波与建筑物结构相互作用过程，分析了冲击波与结构碎块作用机理，发展了一种能够模拟建筑物结构破坏及冲击波传播过程的计算模型和方法。采用建筑物结构工程毁伤载荷作为判据，处理结构在冲击波作用下的破坏问题；利用流固耦合界面算法处理结构运动引起的泄压效应，利用“虚拟网格通气技术”处理结构碎块对冲击波的阻碍作用，模拟了冲击波作用下典型建筑物的毁伤过程及冲击波传播过程。结果表明，该模型在模拟冲击波与结构的作用过程中，压力计算结果与非结构动网格模拟结果符合较好；在典型建筑物毁伤过程的数值模拟中，计算得到的建筑物毁伤效果和冲击波超压分布与建筑物物理毁伤特点符合。

An algorithm for building structural damage under the effect of shock wave

A computational model of simulating the structural damage and the propagation of shock wave was developed in order to study the interaction between blast wave and building. A damage-load criteria of building structures was used to evaluate the destruction of the structure under blast wave, with shock wave impulse used as an indicator of structural failure. Then, the mechanism of the interaction between shock wave and structural fragments was investigated via the simulations of unstructured dynamic grid according to the distribution of pressure field. It has been recognized that there mainly exist three categories of physical effects, i.e., the effect of rarefaction wave caused by the motion of fragments; the impediment effect of structure fragments to shock wave; and the effect of plane wave resulting from the realignment of diffraction wave. Based on the aforementioned analysis, an interface algorithm of fluid-structure coupling was employed to assess the first effect in terms of pressure relief, and “virtual mesh ventilation method” is utilized to deal with the second effect of impediment to shock wave. The results show that the developed model can effectively simulate the propagation of shock wave and reduce the computational cost. Compared to the rigid wall assumptions, the developed model reaches relatively closer agreement with the physical reality. Moreover, the model is simpler and more efficient than the strict coupling method of CSD (computational structural dynamics) / CFD (computational fluid dynamics). Reasonable consistence of the pressure prediction was found between the application of the model and the unstructured dynamic grid simulation. The accuracy, therefore, can meet the engineering requirements. When applied to numerical simulations of the damage process of typical buildings, this model effectively leads to the building damage and shock wave overpressure distributions. The results conform well with the structural damage characteristics, which can provide reference and basis for the damage assessment of explosion shock wave and the building structure.