巨型钢框架—索支撑结构中索突然失效的响应

针对巨型钢框架—预应力索支撑结构中拉索突然失效的响应过程这一传统有限元法难以解决的强非线性问题,采用自编向量式有限元程序模拟了典型巨型钢框架—预应力索支撑结构中索从静止到突然断裂的全部动态过程,并与有限元软件ANSYS计算的结果比较,结果表明,断索后结构水平位移主要因侧向刚度突变产生,索卸载冲击的动效应对位移影响不明显,但对内力影响很大,个别构件动内力可达静止后的近两倍。结构内力重分布情况随断索位置不同有很大差别,设计时应考虑不同的预应力荷载组合。

Failure analysis of cable-stayed steel mega frame by using vector form intrinsic finite element method

Abstract： It is difficult to investigate post-damage behaviors of a cable-stayed steel mega frame after cable loss by using the traditional finite ele- ment method due to state nonlinearity. A vector form intrinsic finite element program was developed to obtain structural dynamic response for ca- ble rupture. Internal force redistribution in the remaining structure was investigated by rising both the vector form intrinsic finite element method ANSYS and the finite element method. Results show that structural horizontal displacement is mainly caused by lateral stiffness jump. Dynamic effects have little influence on it wherever the cable fails. However, dynamic effects have great influence on internal forces. The dynamic axial force can approach to nearly twiee of the static axial force. Different internal force redistributions are reached in the remaining structure when dif- ferent cables break. So it is necessary to consider different prestress load combinations for design