【摘要】 为准确、高效地分析钢筋混凝土(RC)梁柱结构在强动载作用下的损伤破坏甚至倒塌,建立了能够描述大变形、大应变的空间纤维Timoshenko梁单元,并将其与考虑率相关效应的钢筋、混凝土材料模型相结合,通过用户显式单元子程序在ABAQUS中实现。基于所建立的应变速率型3D纤维梁显式单元,借助ABAQUS的前后处理及求解功能,对爆炸荷载作用下的RC梁柱构件的动态响应和破坏模式及RC框架结构的连续性倒塌进行分析。结果表明:建立的应变速率型3D纤维梁柱单元能够合理描述RC构件的变形特性及钢筋、混凝土的应变速率效应;可以模拟爆炸作用下RC构件的弯曲、弯剪及直剪破坏模式,以及RC框架的连续倒塌过程;将纤维梁柱单元与率相关模型相结合于ABAQUS软件提供了一种强动载作用下高效、精确的RC结构非线性分析方法。更多还原

【Abstract】 In order to predict the damage,failure and even collapse of the reinforced concrete(RC) structures subjected to severe dynamic loads precisely and efficiently,a user defined 3D fiber Timoshenko beam element model considering large deformation and large strain was established,which was embedded into the commercial software ABAQUS combining with the rate-dependent constitutive model of steel and concrete.With the help of ABAQUS,the efficient finite element method adopting the proposed rate-dependent 3D fiber Timoshenko beam element was developed to investigate the damage mechanism and progressive collapse of RC structures under severe dynamic loads.The analytical results indicated that the developed user defined 3D fiber Timoshenko beam element model could simulate the deformation,and failure modes of flexure,flexure-shear,direct shear of RC members,and even progressive collapse of RC structures under dynamic loads properly.The user defined rate-dependent 3D fiber Timoshenko beam element model embedded into ABAQUS provides a precise and efficient method to analyze the nonlinear dynamic responses of RC structures.更多还原