拱坝随机振动分析中的精细直接积分法

Precise direct integration method for random vibration analysis of arch dams

为了解决传统方法计算拱坝随机振动效率较低的问题 ,将虚拟激励法和精细直接积分方法结合 ,针对虚拟激励法中荷载为振荡函数的特点提出了振荡函数的精细直接积分法并应用于拱坝地基动力相互作用的有限元边界元无限边界元 (FE- BE- IBE)耦合模型中。以某拱坝为例对Wilson- θ法、Cotes积分法和振荡函数的精细直接积分法进行了比较计算。结果表明 ,精细直接积分方法可以在保证计算精度的前提下增大计算时步的步长 ,提高计算效率 30～4 0倍 ;精细直接积分法中振荡函数的精细直接积分法效率更优于

A new method was developed to analyze arch dam- foundation system that combines pseudo excitation with the finite element-boundary element-infinite boundary element coupled model. The pseudo excitation characteristics were used to formulate new integration equations. An example using the Wilson-θ formula, a precise integration Cotes formula and a precise integration oscillating function integration formula illustrated the high efficiency and accuracy of the precise direct integration method. The results show that the precise direct integration method can increase the calculating step length and the calculating efficiency is up to 30-40 times. The precise integration oscillation function formula is more efficient than the precise integration Cotes formula.