建筑结构动力特性简化与抗震性能有限元分析

Finite Element Analysis of Building Structure for Seismic Performances Based on Dynamic Characteristics Simplification

在建筑结构动力特性与抗震性能分析中,为了缩短运算时间,经常采用简化三维模型,如何提高计算精度将是最关键的问题。通过ANSYS建立简化三维模型与真三维计算模型,对比分析其结构动力特性和抗震性能时程。计算结果表明:应当分开考虑简化三维模型的质心、形心和剪心几何位置,保证计算结果符合客观实际;并根据材料阻尼比、质量矩阵、振型矩阵直接计算阻尼矩阵,可克服Rayleigh阻尼的不足。在简化三维模型中考虑以上因素,运算效率提高,结果真实可靠。

In calculation of building structure dynamic characteristics and seismic performances,a simplified model is usually used for saving time.By using ANSYS,simplified three dimensional model and real dimensional moolel are built to compare the dynamic characteristics and seismic resistance results,which proved that simplified three dimensional model gives out geometric positions of mass center,figue center,and shear center would make results reflect the practical situation;also,calculating damping matrix directly based on material damping ratio,mass matrix,and mode matrix would resolve the deficiency of Rayleigh damping. However,above considerations in simplified three dimensional model would improve arithmetic efficiency and precision.