基于ANSYS平台非线性分析的RC构件建模方法

Modeling Method for RC Members Based on Nonlinear Analysis of ANSYS Software

分离式模型的建立是钢筋混凝土结构和构件仿真中的关键问题,本文基于A N S Y S平台,以某钢筋混凝土实腹深梁为算例,开展2种共节点建模方法和2种不共节点建模方法下的非线性有限元对比分析,探讨建模方法对于仿真结果的影响。结果表明:节点生成切割法与弱耦合法在极限承载力和变形能力等方面的数值模拟结果较接近且均与试验结果较吻合,而强耦合法得出的极限承载力偏高;基于布尔运算切割几何模型的共节点建模方式,适用于形状规整、配筋简单的构件;在钢筋节点与混凝土节点之间,通过节点位移就近耦合的原则建立刚性连接的强耦合法,以及通过节点位移约束方程建立柔性连接的弱耦合法,都有着更强的通用性,能够完成边界条件或配筋方式复杂的构件建模,但相比之下,强耦合法计算精度略低,弱耦合法实现难度较高,所以在工程仿真中需要根据构件的几何特点和配筋方式选择合适的建模方法。

The establishment of a discrete model is a key issue in the simulation of reinforced concrete structures and components.Therefore,this paper based on the ANSYS software,taking a reinforced concrete solid-web deep beam as an example,conducted a nonlinear finite element comparative analysis using two co-node modeling methods and two non-co-node modeling methods to explore the effect of modeling methods on simulation results.The results show that the simulation results of both ultimate bearing capacity and deformation capacity obtained with the method of node generation through dividing the volume are close to the ones obtained with the weak node-coupling method.The simulation results with the above two approaches are in good agreement with the test results.In the simulation,the ultimate bearing capacity obtained with the strong node-coupling method is too high.Furthermore,the modeling method of common nodes,which is based on volume division with the Boolean operation,is just suitable for the members with regular shapes and simple reinforcement layout.The strong node-coupling method establish rigid connections between concrete nodes and rebar nodes with the principle of coupling nodes nearby based on node displacement,while the weak node-coupling method building f lexible connections between concrete nodes and rebar nodes through the node displacement constraint equations.Accordingly,both of the two approaches exhibit stronger versatility,enabling the successful completion of member modeling with complex boundary conditions or reinforcement layout.By comparison,the computational accuracy of strong node-coupling method is slightly lower,while the implementation of weak nodecoupling method is relatively difficult.Consequently,in engineering simulation,it is necessary to select appropriate modeling methods based on the geometric characteristics of components and reinforcement layout scheme.