无限元法在重力坝地震响应中的应用

Application of infinite element method in seismic response of gravity dam

采用无限单元与有限单元耦合的方法研究地震荷载作用下重力坝的响应问题。运用ABAQUS对一具有精确解的算例进行有限元、有限元-无限元耦合分析,验证无限元模拟半无限域问题的正确性和精确性。计算结果发现结构在地震荷载作用下的响应均具有延后性,动应力较静力状态增幅明显;大坝的峰值位移和峰值加速度随着地震强度的增大而增大,增大比例与地震波的强度比值大致相同;地震波频率与结构自振频率越接近则引起的结构响应越大。

ABAQUS was used to analyze a numerical example with exact solution by the finite element method and the finite element-infinite element coupling method. It verified the correctness and accuracy of simulating semi-in-finite domain of infinite element. The response of gravity dam under seismic loads was studied using finite element and infinite element coupling method. The results found that the structural responses under seismic loads have post-poned. The dynamic stress of dam has obviously increased compared with the static state. The peak displacement and the peak acceleration of dam has increased with the increase of earthquake intensity. The increase proportion is roughly the same with the seismic intensity. The closer the seismic wave frequency and the natural frequency of structural vibration,the greater the structural response.