直接求解多维多点非平稳激励的虚拟激励法

PSEUDO EXCITATION METHOD OF DIRECT SOLVING MULTI-DIMENSIONAL AND MULIT-SUPPORT NON-STATIONARY EXCITATION

为了进一步推广多维多点非平稳虚拟激励法在工程中的应用和解决传统虚拟激励法在通用有限元中实现困难等问题,以一座铁路钢构桥为例,基于ANSYS软件平台,研究了虚拟激励法在实际工程抗震分析中的应用问题,通过在总质量矩阵上"置大数"的方法,将单维单点激励扩展到多维多点虚拟激励,并将非平稳激励转化为一系列确定性外力作用,从而避免了求解静力影响矩阵的繁琐。研究结果表明:所采用的方法具有较高的精度,并能高效地将多维多点非平稳虚拟激励法与通用有限元软件结合,节约了自编程序的时间,使得工程师更容易接受和运用。

To further promote the application of multi-dimensional and multi-support non-stationary pseudo excitation method in practical engineering and overcome the difficulties of implementing this method in general finite element analysis, a typical railway rigid frame bridge is employed for example to study the application of pseudo excitation method in practical engineering based on Ansys software platform. Through the approach of ＂placing large numbers＂ on general mass matrix, the one-dimensional and one-support excitations are extended to multi-dimensional and multi-support pseudo excitations, and non-stationary excitations are converted to series of deterministic external forces to avoid the complexity of solving the static influence matrix. The results show that, the method proposed has high accuracy, and can combine the multi-dimensional and multi-support non-stationary pseudo excitation method with general finite element software efficiently, so that engineers are more likely to accept and use this method without self-developed programs.