半刚接钢框架的动力分析

DYNAMIC ANALYSIS OF STEEL FRAMES WITH SEMI-RIGID CONNECTIONS

  • 摘要: 推导了半刚接钢框架动力有限元的质量矩阵和刚度矩阵. 建立了具有不同节点初始刚度的半刚接多层钢框架及相应刚性框架的计算模型. 采用ANSYS软件进行数值模拟分析,研究了节点刚度对结构自振频率的影响以及结构在谐振荷载作用下的响应,对地震波激励下的结构进行了时程分析. 分析结果表明不半刚接框架节点的柔性对结构自振频率产生较大的影响,节点柔性越大,结构自振频率降低也越大,结构的抗震设计应考虑节点柔性的影响;半刚接钢框架顶点位移和柱底剪力时程曲线在地震波激励时间内表现出良好的稳定性,柔性连接可以代替刚性节点用于抗震区的钢框架设计中.

     

    Abstract: Mass matrix and stiffness matrix of semi-rigid frames fordynamic finite element analysis are deduced.Multistory frames with semi-rigidconnections of different initial stiffness are constructed together with thecorresponding rigid frame. Finite element analysis software ANSYS is used toperform the numerical analysis. The influence of connection stiffness on naturalfrequencies of structures is analyzed. The response of different framesaccording to harmonic loading with different frequencies is studied.Further,by adopting a time--dependent method, structures under excitation of seismicwaves are analyzed. Analysis results show that the connectionflexibility has agreat effect on structure's natural frequencies. The naturalfrequency decreases with the increase of connection flexibility. It isnecessary to consider theconnection flexibility in the seismic design of steel structures. Timecurvesof top point lateral displacement and column base shearing force ofsemi-rigid frames behave stably during the excitation time. Flexibleconnections can be used instead of rigid connections in seismic design ofsteel frames.

     

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