半刚性连接空间钢框架结构的二阶非弹性分析

将有限单元法与梁柱法相结合，建立了半刚性连接的空间钢框架结构的二阶弹塑性分析方法。该法综合考虑了几何、材料和半刚性连接效应。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建立的严格三维梁柱单元刚度方程，包含了轴向、剪切、双向弯曲与扭转及其各耦合效应。三维单元简化塑性区模型可模拟塑性扩展，利用梁单元两端抗转弹簧来模拟半刚性连接效应。使用包括几何、材料和连接非线性的数值算例来检验文中方法和所编计算机程序的可行性、有效性与精确度。算例表明，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荷载与失稳模态，可提高结构非线性空间性能的分析效率。该程序可用于三维结构的多重非线性全过程分析，为建立高层钢结构的高等分析方法奠定了基础。

Second order inelastic analysis approach for space steel frame with semi-rigid connections

A advanced analysis approach for space steel frame with semi-rigid connections was proposed based on the combination of finite element method and traditional beam-column method, and geometric, material and semirigid connected effects were considered in the approach. The stiffness equation for stringent three dimension beamcolumn element was derived using nonlinear continuum mechanics and stability interpolation function considering shear effects, and the coupling effects between axial, bi-direction flexural and torsional displacements were considered in the equation. A simplified plastic zone model for three dimension beam-column element was established to stimulate semi-rigid connection effect. Numerical examples including geometric, material and connection nonlinearites were used to stimulate semi-rigid connetion to demonstrate the feasibility, accuracy and efficiency of the proposed analytical method and computer program. The developed computer program can be used to predict accurately the ultimate strength and instability mode of three dimension structures by one element per member in most cases, and the suggested triple nonlinear analysis method establishes the base to generate advanced analysis method of high-rise steel structures.