直接求解多维多点地震动方程的虚拟激励法

PSEUDO EXCITATION METHOD OF DIRECT SOLVING GROUND MOTION EQUATION OF MULTI-DIMENSIONAL AND MULTI-SUPPORT EXCITATION

为解决传统的虚拟激励法多维多点虚拟激励荷载输入繁琐及在通用有限元软件中实现困难的问题,通过在质量矩阵上"置大数"的方法快速实现地震动输入,更快捷地将一维多点激励扩展到多维多点虚拟激励,运用绝对位移直接求解运动方程。相比传统的多维多点虚拟激励法,不必将绝对位移分解为拟静力位移项和动力相对位移项,避免了求解静力影响矩阵的繁琐,能更高效的实现多自由度大跨结构多维多点虚拟激励荷载在通用有限元软件中的输入与分析,不需要编制专门的计算程序,使得虚拟激励法在理论上和工程中的应用得到进一步的拓展。

This work is concerned with the input and implementation issues of the pseudo load in the finite element software for a pseudo excitation method. The input of ground motion is achieved more expediently through a ＂place large numbers＂ approach. Therefore, the pseudo excitation is swiftly extended from one-dimensional and multi-supports （ODMS） to multi-dimensional and multi-supports （MDMS）, and the motion equations are solved directly through absolute displacement. Compared to the traditional MDMS pseudo excitation method, the directly-solving method through the absolute displacement does not decompose the absolute displacement into quasi-static and dynamic relative displacement items, avoids solving the static influence matrix, more efficiently realizes the input of pseudo excitation loading and the analysis of multiple-degree-of-freedom structures in the finite element software, and does not require a special program. The pseudo excitation method is further expanded in theory and engineering applications.