摘要:风荷载的数值模拟在结构设计中起着非常重要的作用。在土木工程脉动风速时程的各种数值模拟方法中,谐波叠加法最为常用。而且,通过引入FFT和不同插值技术可以在不显著地影响模拟精度的情况下,大大地缩短模拟计算所花费的时间。本文基于两次多项式、三次多项式、以及两种不同边界条件三次样条函数插值技术的谐波叠加法来模拟一幢100米高高层建筑上10个点的脉动风速时程,通过均方根误差( Root Mean Square Error, )和相对误差系数( Error factor, )两项指标来评价不同插值技术与传统谐波叠加法(未引入插值技术)相比较的插值模拟计算精度,并且记录各自所耗费的时间,综合比较模拟效率和精度以找出最为适合的一种插值技术。结果表明:基于第一种边界条件三次样条函数插值技术的谐波叠加法为最佳的模拟方法。
Abstract: The numerical simulations of wind loads are critical in the design of structures. Harmony superposition method is most widely used among all the simulation methods for tall buildings. Likewise, the time expense of harmony superposition method can be significantly shortened by resorting to the FFT technique and various kinds of interpolation techniques without a significant loss of the accuracy. Square polynomial interpolation technique, cubic polynomial interpolation technique, and two kinds of spine interpolation techniques with different end conditions are adopted in the paper to simulate the wind velocity time series at 10 points in a 100-metre building. Two indices, designated as the root mean square error ( ) and error factor ( ), are introduced to measure the accuracy of these four interpolation techniques with respect to the traditional harmony superposition method (without introducing the interpolation technique) and likewise their time expense is recorded. Finally, the best interpolation technique is picked out through comprehensively taking into account both accuracy and time expense.