核能设施地震动模拟中目标反应谱与功率谱转换方法探讨

Relationships between Response Spectra and PSD Functions for Simulation of Artificial Earthquakes for Nuclear Power Plant Design

针对核能设施地震动模拟中合成人工地震动功率谱包络的要求,比较由反应谱计算功率谱的几种常用方法,并分析各方法中相关参数对结果的影响。此外,采用拟合小阻尼反应谱生成人工时程并取各时程功率谱平均值的方法,可得到与反应谱相对应的功率谱。以AP1000和RG1.60的反应谱及其对应的目标功率谱为分析对象,考察由反应谱计算功率谱各种方法的计算精度,并着重对Kaul方法的适用性进行分析。最后给出核能设施地震动模拟时,获得足够精度功率谱的相关建议。

Abstract. The requirements to envelope a target power spectral density （PSD） function compatible with the design response spectra are usually prescribed by seismic codes for generating artificial time series as seismic input. This paper contrasts several methodologies which are most widely used in engineering seismology for defining spectrum compatible PSD. Parameters of these methodologies were analyzed using the RG1.60 and AP1000 design response spectra of safe shutdown earthquake. The emphasis was then placed on the method proposed by Kaul and its applicability was illustrated. Artificial time histories, whose response spectra were in agreement with 2%-damped design response spectrum, were generated and their average PSD would be the minimum PSD requirements compatible with the spectrum. Numerical examples show the accuracy and applicability of those approaches.