钢筋混凝土梁非线性有限元分析方法  

AN APPROACH OF NONLINEAR FINITE ELEMENT ANALYSIS OF REINFORCED CONCRETE BEAM

作　　者：周凌远[1] 李乔[1] 

机构地区：[1]西南交通大学土木工程学院,成都610031

出　　处：《工程力学》2011年第1期82-86,共5页Engineering Mechanics

基　　金：国家科技支撑计划项目(2006BA904B03)

摘　　要：针对钢筋混凝土结构有限元分析中,材料进入非线性阶段后,难以通过梁理论准确描述混凝土截面和钢筋应力状态的问题,提出了基于柔度法和分布式塑性理论的钢筋混凝土梁单元材料非线性方法——网格截面法。这种方法采用平面等参单元将梁单元网格化,由单元轴向积分点位置截面网格积分点的混凝土应力描述单元截面应力分布,同时考虑钢筋对刚度的贡献,并通过对截面网格材料的积分计算积分点位置的截面刚度矩阵,再利用力插值函数和能量原理得到梁单元的柔度矩阵,进而对柔度矩阵求逆计算单元刚度矩阵。通过算例验证该方法在钢筋混凝土承载力分析时的准确性。A beam element with a meshed section based on distributed plasticity and flexibility theory is presented for the material nonlinear finite element analysis of a reinforced-concrete framed structure,the sections of a concrete beam element are discretized into the plane isotropic components in this formulation,the stress distribution on the sections is described with the stresses at quadrature points in the mesh,the stiffness matrices of the sections are calculated by integration of the stress-strain relations of the material on the meshes and the contribution of the stiffness by reinforcing steel is also counted,the flexibility matrix of the element is formed by integration of section flexibility matrices with force-interpolation functions,and then it is inverted to obtain the element stiffness matrix.Finally,a numerical example of the ultimate load capacity analysis of a reinforced concrete beam illustrates the accuracy of the formulation.

关 键 词：有限元 钢筋混凝土梁 柔度法 网格截面 极限承载力 

分 类 号：TU375.1[建筑科学—结构工程] O241.82[理学—计算数学]