摘要
针对传统的谐波合成法模拟超高层建筑脉动风速场存在计算量大的问题,提出了考虑互谱密度矩阵为复数矩阵的一般情况,使用插值精度较高的样条插值技术来减少Cholesky谱矩阵分解的次数,再使用FFT技术进一步加快模拟计算速度的改进谐波合成法。为了阐明改进谐波合成法具有较好的模拟精度和较快的计算速度,运用该方法模拟了一栋225m高的超高层建筑脉动风速场,并与仅使用FFT技术的谐波合成法即传统谐波合成法的模拟结果进行了对比分析。模拟结果的对比分析表明:尽管改进后的谐波合成法对谱分解矩阵采用了插值近似措施,但模拟的随机风速样本仍具有很好的精度,计算效率比传统的谐波合成法有了较大的提高。
In order to cope with large computational efforts needed in traditional harmony superposition method(referred here to as THSM),an improved harmony superposition method(referred to as IHSM)was proposed to simulate the fluctuating wind speed fields of super tall buildings.Taking into consideration that the elements of cross-power spectral density matrix are complex values,the proposed IHSM introduces the spline interpolation technique to reduce the number of Cholesky decomposition of spectral density matrix,subsequently uses fast Fourier Transform(FFT)to further accelerate computation for simulating the fluctuating wind velocity fields.In order to demonstrate the superiority of the IHSM,the simulations of the wind velocity fields for a super tall building with 255 m height were carried out using both IHSM and THSM.The numerical results indicate that although IHSM introduces the spline interpolation approximation in decomposing the cross-power spectral density matrix,the simulated wind velocity samples based on IHSM are of very good precision with reference to THSM.Likewise,the computational efficiency based on IHSM is much higher than that based on THSM.
出处
《振动与冲击》
EI
CSCD
北大核心
2008年第12期151-156,共6页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(No.50578092)
上海大学研究生创新基金(No.A.16-0118-08-002)资助项目
关键词
数值模拟
超高层建筑
脉动风速
谐波合成法
样条插值
FFT技术
numerical simulations
super tall buildings
fluctuating wind velocity fields
harmony superposition method(HSM)
spline interpolation
FFT technique
