A method has been developed which takes a single seed earthquake time history and produces multiple similar seed earthquake time histories. These new time histories possess important frequency and cumulative energy attributes of the original while having a correlation less than 30% (per the ASCE/SEI 43-05 Section 2.4 [1]). They are produced by taking the fast Fourier transform of the original seed. The averaged amplitudes are then pared with random phase angles and the inverse fast Fourier transform is taken to produce a new time history. The average amplitude through time is then adjusted to encourage a similar cumulative energy curve. Next, the displacement is modified to approximate the original curve using Fourier techniques. Finally, the correlation is checked to ensure it is less than 30%. This process does not guarantee that the correlation will be less than 30% for all of a given set of new curves. It does provide a simple tool where a few additional iterations of the process should produce a set of seed earthquake time histories meeting the correlation criteria.
展开▼
机译：已经开发出一种方法，该方法采用单个种子地震时间历史并产生多个相似的种子地震时间历史。这些新的时间历史记录具有原始数据的重要频率和累积能量属性，而相关性小于30％（根据ASCE / SEI 43-05第2.4节[1]）。它们是通过对原始种子进行快速傅里叶变换而产生的。然后，将平均幅度与随机相位角进行比对，并进行快速傅立叶逆变换以产生新的时间历程。然后调整平均幅度随时间变化，以鼓励产生类似的累积能量曲线。接下来，使用傅立叶技术修改位移以近似原始曲线。最后，检查相关性以确保其小于30％。此过程不能保证对于所有给定的新曲线集，相关性都将小于30％。它的确提供了一个简单的工具，在此过程中，如果再进行几次迭代，就可以产生一组满足相关标准的种子地震时间历史记录。
展开▼
