基于扩展有限元、内聚力单元和单元失效的受弯钢筋混凝土梁数值模拟分析

Numerical Simulation Analysis on Bending Reinforced Concrete BEAM Based on Extended Finite Element Method,Embedded Cohesive Element and Element Failure for Explicit Dynamic Analysis

利用Abaqus中扩展有限元法、内聚力单元和显示动力分析模块下单元失效分析钢筋混凝土梁的受弯响应,对比混凝土4点受弯梁试验和有限元分析的整体性能、损伤与失效,提出混凝土的精细化建模方法。根据模拟结果可知:扩展有限元法和内置内聚力单元模拟混凝土整体性能和拉裂行为精度较高;扩展有限元法模拟的混凝土裂纹扩展路径自由,适合对受力或相互作用复杂的混凝土进行精细化建模与损伤分析;内置内聚力单元的裂纹形成与扩展依赖单元网格密度与形状,适合在相关理论成熟或试验数据全面的基础上做影响参数分析;设置单元失效准则可同时模拟混凝土的压溃和拉裂行为,但损伤发展较快,精度偏低。

The bending behavior of reinforced concrete BEAM is analyzed based on the extended finite element method(XFEM),embedded cohesive element(ECE)and failure element for the explicit dynamic analysis(FED)in Abaqus software.Their results are compared with the test on the four-points bending BEAM for assessing the associated prediction of overall performance,damage and failure of concrete.Based on this,relevant finite element model constructions are proposed.The results show that:the XFEM and ECE can lead a relatively high accuracy for the overall performance and cracking of concrete;since the crack growth of XFEM is relatively unlimited,it is appropriate to the simulation or study on the concrete structures under complicated loads or interactions;the crack growth of ECE relies on the element mesh,which is appropriated to the parametric analysis based on the test investigation;the cracking and crushing of concrete can be realized by FED,but its damage development is relatively at a high rate leading to a low accuracy.