基于初始压力间断的冲击波模拟方法

Simulation method of shock wave based on initialized pressure discontinuity

冲击波是引起结构破坏的首要因素,抗爆结构性能分析通常有两种方法,一是把冲击波以压力函数的形式直接加于结构上;二是通过分别建立炸药与空气的网格模拟得到冲击波,然后将冲击波荷载以节点速度或加速度的形式耦合到结构结点上进行计算。前一种方法基于许多假定,不够真实,而爆炸模拟存在的问题较多,主要是炸药网格单元较小,由此考虑炸药单元与空气或结构单元网格的协调性会导致单元较多,计算量较大,峰值压力和作用时间的可调整范围有限。为解决上述问题提出用初始压力间断的原理直接生成冲击波的方法,并对决定冲击波峰值压力和作用时间的因素进行了分析。

Shock wave is the chief factor that causes the damage of the structure. Two methods can be used to analyze the anti-blast performanee of the strueture.the first is direet infliet shoek wave pressure on the strueture;the seeond is through building the grids of detonator to obtain the shoek wave, then eoupling shoek wave load in the format of node veloeity or aeeeleration on the node to proeess numeration. The first method is based on many assumptions, whieh are not authentie. However, many problems often emerge in blast simulation by using the latter. The root eause is that the size of the detonator grid is very small,and eonsidering the harmony of detonator and air or strueture grid eell will lead many eells, then workload beeomes very big. In addition, the peak value and aetion time of shoek wave pressure can only be adjusted in limited bound. In order to solve the above-mentioned problems, a new method was presented, whieh ereates shoek wave on the foundation of initialized pressure diseontinuity, and analyzes the faetors whieh ean influenee the. peak value pressure and aetion time of the shove wave.