加权残值法在钢筋混凝土拱桥非线性有限元分析中的应用

本文用圆弧梁离散拱肋；用圆柱拖带坐标、三次位移插值函数及平截面假定来描述单元位形；用加权残值配点法来消除曲梁单元的剪力与膜力闭锁。按基于连续介质力学的Ｕ．Ｌ．列式建立单元增量平衡方程，以考虑几何非线性。假定钢筋为理想弹塑性材料。按三参数各向同性强化塑性模型，建立混凝土的弹塑性本构矩阵。将拱单元分段分块，根据钢筋及砼的本构特性，建立拱单元及梁段单元的弹塑性刚度矩阵，以考虑材料非线性。用编制的程序对两座模型拱桥进行计算，计算结果与模型测试结果接近

Application of weighted residuals in the nonlinear finite element analysis of R.C. arch bridge

Arch structure is discretized as space curved beam elements. The initial and deformed configuration is described by the cylindrical co\|ordinate system. The Green strian tensor is formed, basically convected co\|ordinate system. The displacement compontents of the arch element is interploated using three\|order polynomials, the axial is specified by linear interpolation. The membrane locking and shear locking are eliminated by method of weighted residuals. In the paper, the incremental equilibrium equation are derived from the continuum mechanics based on updated Lagrangian(U.L.) virtual incremental formulations that the shear deformation is accounted for. Elastic\|plastic stiffness matrices are computed according to C.T.Chen\|Chen W.F concrete plastic model and integreted along the curved beam and in the cross section of beam piecemealy. According to the above\|mentioned approach,the computer program has been drawn up.Good agreement between the computed results and the experiment results is evident.