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为深入掌握结构在地震作用下的可靠性,研究地震激励时间及安全界限对结构抗震可靠性的影响。基于Matlab,首先对结构在高斯过滤白噪声地震动模型(Kanai-Tajimi谱)激励下的随机响应进行了分析,然后分别采用泊松过程法、马尔科夫过程法、瑞利极值分布法对结构随机响应过程超越安全界限的概率进行了计算,三者结果基本接近,较可靠地反映出结构动力可靠度变化规律。结果表明,结构动力可靠度随激励时间的增长而下降,当安全界限大于某确定值时,动力可靠度与激励时间的关系接近于线性,当安全界限小于该值时,动力可靠度与激励时间呈二次非线性关系;结构动力可靠度随安全界限增大而增大,激励时间越长,动力可靠度与安全界限关系曲线越陡,激励时间越短,动力可靠度与安全界限关系曲线越平缓。
In order to further understand the reliability of the structure under the action of earthquake and study the influence of seismic excitation time and safety margin on the seismic reliability of the structure. Based on Matlab, the random response of the structure excited by the Gaussian filter white noise ground motion model (Kanai-Tajimi spectrum) is analyzed. Then the Poisson process method, the Markov process method and the Rayleigh extremum distribution method The random response process of the structure exceeds the probability of safety margin is calculated, the results of the three are basically close, more reliably reflect the structural dynamic reliability variation. The results show that the structural dynamic reliability decreases with the increase of excitation time. When the safety margin is greater than a certain value, the relationship between dynamic reliability and excitation time is close to linear. When the safety margin is less than this value, the dynamic reliability and excitation time The dynamic reliability of structure increases with the increase of safety margin. The longer the excitation time, the steeper the curve of dynamic reliability and safety margin, the shorter the excitation time, the curve of dynamic reliability and safety margin is more curve gentle.