基于零厚度粘聚力单元的钢筋混凝土板在爆炸荷载下的动态破坏过程分析

DYNAMIC FAILURE ANALYSIS OF REINFORCED CONCRETE SLAB BASED ON COHESIVE ELEMENT UNDER EXPLOSIVE LOAD

军火库或危险品仓库存在着偶然爆炸的威胁,而钢筋混凝土是这些建筑物的主要构成材料,因此研究钢筋混凝土结构在爆炸荷载下的破坏过程具有重要意义。该文基于LS-DYNA动力有限元程序,利用任意拉格朗日–欧拉(ALE)方法,以及多物质流固耦合方法对混凝土结构在爆炸荷载作用下的动态破坏过程进行研究。为了更好分析混凝土结构在爆炸荷载作用下的动力响应,采用了考虑应变率影响的钢筋和混凝土材料本构模型,并引入零厚度粘聚力单元来模拟混凝土的动态破坏过程,克服基于侵蚀算法单元删除带来的质量损失问题。该文首先介绍零厚度粘聚力单元模型的生成过程并对比试验结果,验证所建立的零厚度粘聚力单元模型的合理性。其次,对比不同爆炸荷载下基于侵蚀算法以及零厚度粘聚力单元两种不同模拟方法的模拟结果,验证基于零厚度粘聚力单元模拟的优越性。最后基于零厚度粘聚力单元模型,分析不同爆炸荷载对混凝土结构动态破坏过程以及碎片抛射的影响。

For arsenal or dangerous goods warehouse,accidental explosion may happen.Since the warehouse is mainly made of reinforced concrete materials,it is therefore essential to study the failure process of reinforced concrete under explosive loading.In this study,based on the LS-DYNA software,the paper studies the dynamic failure process of reinforced concrete under explosive loading,which was investigated by using the Arbitrary Lagrange Euler(ALE)method and the multi-materials Fluid-Solid coupling method.In order to analyze the dynamic response of concrete structure under explosive load,strain rate dependent constitutive models were adopted for the rebar and concrete.In addition,zero thickness cohesive element was introduced to simulate the dynamic breakup process of concrete structure,which can overcome the mass loss problem caused by the erosion algorithm.In this paper,the generation process of the cohesive element model was firstly introduced.The developed model was then verified by comparing the numerical results with the experimental results.To demonstrate the superior capability of the proposed cohesive element model,the simulation results from the proposed model were compared with those obtained from erosion methods.Finally,based on the cohesive element models,the influence of different explosive loads on the dynamic failure process of concrete structure and the debris launching were analyzed.