杆件结构几何非线性分析的梁柱单元

采用稳定函数考虑单元P-δ效应，建立了空间弹性梁单元方程．梁单元的内力计算考虑了总量算法、增量算法、总量算法并考虑弓形效应以及增量算法并考虑弓形效应四种不同情况．通过典型算例的几何非线性分析，对比了四种自编梁单元以及ANSYS中的BEAM4和BEAM189单元的精度．进行几何非线性分析时，总量算法优于增量算法；当采用总量算法并考虑弓形效应时，自编梁单元几何非线性分析的精度优于BEAM4单元的，与BEAM189单元相当，甚至略优于BEAM189．

Beam-column Elements of Geometric Nonlinear Analysis of Frame Structures

Formulae of a three-dimensional elastic beam element are developed, by utilizing stability functions to account for the element P-8effect. Four kinds of techniques, namely, total algorithm, incremental algorithm, total algorithm with bowing effect and incremental algorithm with bowing effect, are used to calculate the element internal forces. Geometric nonlinear analyses of typical examples are conducted to compare the accuracy of proposed beam elements with that of BEAM4 and BEAM189 element in ANSYS program. The numerical results show that the total algorithm is better than the incremental algorithm in geometric nonlinear analysis. When total algorithm and bowing effect are considered, the accuracy of proposed beam element is better than that of BEAM4 element, and is comparable to, in some cases even better than, that of BEAM 189 element.