模拟流体冲击致结构破坏问题的SPH-PD耦合方法  

SPH-PD coupled method for simulation of structure failure impacted by fluid

作　　者：时浩天 郭力[1] SHI Haotian;GUO Li(School of Civil Engineering,Southeast University,Nanjing 210000,China)

机构地区：[1]东南大学土木工程学院,南京210000

出　　处：《振动与冲击》2022年第17期170-176,203,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(51578142)。

摘　　要：流体冲击致结构破坏在自然灾害、海岸及近海工程中广泛存在,是典型的流固耦合问题。基于网格的方法在捕捉流体自由表面、模拟结构开裂破坏的过程中存在固有的困难。针对此类问题,发展了一种基于光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)和近场动力学(peridynamics,PD)耦合求解冲击破坏问题的数值方法。采用动态边界条件的思想,利用SPH和PD在数值计算过程上的相似性,通过设置恰当的光滑长度,自动识别流固界面并进行数据交换,高效实现了耦合计算过程。该方法一定程度上规避了无网格法在施加本质边界条件上的困难,综合了SPH在处理自由表面流、PD在处理材料断裂失效上的优势,可以实现一定规模复杂流固耦合问题的模拟。最后,采用提出的SPH-PD耦合方法,模拟了溃坝冲击下游弹性挡板问题,成功捕捉到结构经历大变形直至断裂失效的行为。Structural damage caused by fluid impact is a typical fluid-structure interaction problem,it widely exists in natural disasters,coastal and offshore engineering.Mesh-based method has inherent difficulties in capturing fluid free surface and simulating structural cracking and failure.Here,to solve these problems,a numerical method based on coupling of smooth particle hydrodynamics(SPH)and peridynamics(PD)was developed to solve impact failure problems.Using the idea of dynamic boundary conditions and the similarity of SPH and PD in numerical calculation process,the coupling calculation process was realized efficiently by setting the appropriate smooth length,automatically identifying fluid-structure interface and exchanging data.This method could avoid difficulties of meshless method in imposing essential boundary conditions to a certain extent,integrate advantages of SPH in dealing with free surface flow and PD in dealing with material fracture failure,and realize simulation of complex fluid-structure interaction problems on a certain scale.Finally,the proposed SPH-PD coupled method was used to simulate dam break impacting downstream elastic baffle,and the behavior of the structure undergoing large deformation until fracture failure was successfully captured.

关 键 词：流固耦合 光滑粒子流体动力学(SPH) 近场动力学(PD) 动态边界条件 无网格法 结构破坏 

分 类 号：TH113[机械工程—机械设计及理论]