【摘要】 为了考虑平面框架结构中梁柱构件在变化轴向荷载作用下的P—Δ效应,采用三节点平面梁柱单元,选用三点插值的Hermite多项式作为其形函数,根据最小势能原理推导了单元线性刚度矩阵和初应力刚度矩阵,并分别阐述了应用该单元求解结构屈曲荷载因子及迭代计算荷载—位移反应的方法.通过两个简单算例,验证该单元比常规的二节点常轴力梁柱单元更有效,精度更高.更多还原

【Abstract】 To take into account theP-Δeffects of beam-column members in a planar frame structure subjected to varying axial forces,a three-node planar beam-column element is formulated by adopting three-point interpolation Hermite polynomials as its shape functions,and the elemental linear stiffness matrix and initial stress stiffness matrix are derived according to the minimum potential principle.The procedures of applying this element to solve the buckling load factor and compute iteratively the load-displacement responses of a frame structure are described respectively.It is verified through two simple examples that this element is more effective and more accurate than the conventional two-node beam-column element subjected to constant axial forces.更多还原