空间钢框架精细塑性铰法高等分析  

REFINED PLASTIC HINGE ANALYSIS OF SPATIAL STEEL FRAMES

作　　者：刘永华[1] 张耀春[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150090

出　　处：《工程力学》2006年第A01期108-116,共9页Engineering Mechanics

摘　　要：几何非线性单元的精度主要决定于单元恢复力的计算方法，刚度矩阵对单元精度的影响很小。建立了考虑剪切变形影响的精细塑性铰法空间梁柱单元。单元二阶效应由稳定函数考虑，采用精细塑性铰模型考虑材料非线性，可考虑截面的逐渐屈服以及由残余应力引起的分布塑性对单元刚度的削弱。单元刚度矩阵包含了轴向、弯曲和扭转位移之间的耦合效应。利用ANSYS软件的用户可编程特性（UPFs）编写了单元程序，通过连接将用户单元添加到ANSYS软件单元库中。算例分析结果表明，采用作者提出的单元时，每根杆件用一个单元模拟分析可达到很高精度，而采用ANSYS中BEAM189单元时，每根柱需3-4单元模拟才能达到合适的精度。分析结果还表明，多高层框架结构中构件剪切变形的影响不可忽略。Method for computing the element restoring force, rather than the stiffness matrix, is the most important factor that determines the accuracy of a geometric nonlinear finite element problem. The formulation of a spatial beam-column element with shear deformation for the purpose of refined plastic hinge analysis of 3-D steel frames is presented. Second-order effects are captured through stability functions. Material nonlinearity is modeled using refined plastic hinge method, which can account for the gradual yielding of the section and the reduction of the element stiffness due to distributed plasticity resulting from residual stresses. The coupling terms between the axial, lateral and torsional displacements are included in element stiffness matrix. Using the User Programmable Features （UPFs） of ANSYS program, the element routines have been developed and successfully incorporated into ANSYS program. The results of numerical examples show that only one proposed element, in contrast to three or four BEAM189 elements of ANSYS program, is necessary to model a column of spatial frames with excellent accuracy. The analysis results also indicate that shear deformation of members must be considered in the analysis of multi-storey frame structures.

关 键 词：空间钢框架 高等分析 精细塑性铰法 单元恢复力 刚度矩阵 剪切变形 ANSYS用户可编程特性 

分 类 号：TU973.13[建筑科学—结构工程]