阻尼矩阵选取对核电厂结构地震响应的影响分析

已有研究表明时程动力法中阻尼矩阵的确定对复杂结构工程的地震响应有明显的影响,而核电厂安全相关结构在抗震分析时通常采用时程动力法。为研究阻尼矩阵的选取对核电厂结构的地震响应的影响,从比例阻尼拟合的精度出发,基于结构不同振型对结构产生的影响程度入手,建立更为精确的结构阻尼模型,即等效比例阻尼,并进一步考虑结构自振特性以加权最小二乘法拟合确定等效比例阻尼系数,提出了核电厂结构地震响应分析相应的计算方法。计算结果表明,该方法较传统比例阻尼的方法更接近精确解,是核电工程抗震分析的一个实用参考应用。

Effect of damping matrix selection on seismic response of nuclear power plant structures

It shows that determination of damping matrix in the dynamic time-history analysis method strongly affects the seismic response of complex engineering structures, and the safety related structures of nuclear power plant in dynamic analysis usually adopts the dynamic time-history analysis method. To study the effect of determination of damping matrix on the seismic response of nuclear power plant structure, we consider the proportional damping fitting accuracy of nuclear power plant structure, and the influence of different shape of structure based on structural damping, to set up a more precise model, an equivalent proportional damping model. Furthermore, a corresponding method of the seismic response analysis of the nuclear power plant structure is proposed by taking consideration of structural vibration characteristics, which is, determining the proportional damping coefficient by weighted least square fitting method. The application and analysis show that the method is more consistent with the exact solution than the method with traditional damping coefficient, and it is suitable for the seismic response of nuclear power plant structure.