空间钢框架结构的改进塑性区模型

为探讨三维结构的高等分析方法 ,给出了基于非线性连续介质力学理论和考虑剪切效应的稳定插值函数所建立的严格三维梁柱单元切线刚度方程 ,并提出了基于三维单元改进塑性区模型的双重非线性刚度方程。在方程中考虑了轴向位移、弯曲位移和扭转位移的耦合效应 ,使用包括几何与材料双重非线性的数值算例来验证本文方法和计算机程序的可行性、有效性与精确度。利用该程序 ,每个构件只需一个单元即可准确预测三维结构的极限承载力与失稳模态 ,可提高结构非线性空间性能的分析效率。

A MODIFIED PLASTIC ZONE MODEL FOR SPACE STEEL FRAME STRUCTURES

For exploring the advanced analysis approach of three dimension structures,a tangent stiffness inquation for stringent three dimension beam-column element is proposed based on nonlinear continous mechanics and stability interpolation function considering shear effects,and the dual nonlinear incremental stiffness equation is induced based on proposed simplified plastic zone model for three dimension beam-column element;the coupling effects between axial,flexural and torsional displacements are considered in the equation.Numerical examples including geometric and material nonlinearities are used to demonstrate the feasibility,validity and accuracy of the proposed analytical method and computer program.The developed computer program can be used to predict accurately the utmost resistance capability and instability modality of three dimension columns and space frames by modelling each physical member as one element in most cases.