【摘要】 在文献［１］高阶钢筋混凝土膜元的基础上，提出了一种具有１４个节点的高阶钢筋混凝土平板单元．钢筋混凝土材料模型仍采用Ｖｅｃｃｈｉｏ的抹平旋转裂缝模型，几何非线性仍采用所谓总体Ｌａｇｒａｎｇｅ列式法，非线性方程采用割线刚度位移增量迭代法．数值算例表明本文的方法是可靠的，高阶平板单元虽然列式复杂，但与低阶元相比，其计算量要少且精度要高更多还原

【Abstract】 Based on the high order nonlinear membrane elements presented in Reference , the formulation of a higher order rectangular 14 noded RC Plate element is proposed for the analysis of RC panel walls. The nodal DOF of the element presented are assumed to be in plane displacements u, v; transverse deflection w and cross section rotations ψ x, ψ y , and their derivatives (with respect to x ). Of the element displacements consequently are 3rd order Hermite polynomial in the x direction and 6th order Lagrangian polynomial in y direction along the element for transverse deflection w , and the full cubic polynomials for all others. Green’s strain displacement relations are used to take into account geometric nonlinear behaviour of the panel walls. The plate element is considered to be composed of a series of layers. Material behaviour of concrete layers and steel reinforcement layers are defined separately on the basis of the smeared, rotating crack model proposed by Vecchio and Collins for RC membrane elements. Usually, according to Di and Cheung, a selective reduced order of integration is employed to improve the shear locking in thin RC panel walls. Based on the constant are length method presented by Crisfield et al., a new constraint equation is developed in this study to trace the complete nonlinear equilibrium paths of RC panel walls under nonproportional loadings. This procedure employs projected length other than arc length as a control variable. The iterative procedures are carried out in the space R n+1 . Both the load factor and displacements are used here as iterative parameters. Hence whether or not the structural failures occur the displacements and associated loads can be calculated without any diffculties. Numerical examples are given in the paper to demonstrate the applications of the proposed method to practical RC panel walls. Comparisons between present results and previous work have shown that the present higher order finite element formulation, including the material models and solution procedures, are more efficient than lower order elements by others, especially for the postfailure behaviours of RC plates.更多还原