地震作用的相关性对结构瞬态响应的影响

THE TIME INFLUENCE OF CORRELATED SEISMIC ACTION ON STRUCTURAL RESPONSE

  • 摘要: 地震作用一般分解为水平运动分量和竖向运动分量,在这两个运动分量的作用下,结构发生大变形时,可能会经历由地震运动分量演变的外部激励和参数激励过程。由于运动分量间的相关性,推导出实际上这两个激励过程也是相关的,而且是完全相关的,但在过去的研究中,为了简化分析,常常假设这两个激励过程是完全独立的。该文以高斯白噪声和过滤高斯白噪声过程模拟地震动过程,以某一单层框架结构为研究对象,采用累积矩截断法,分析高斯白噪声和过滤高斯白噪声这两种地震动激励下单层框架结构的非平稳地震响应。同时考虑地震动分量间的相关性,得到更为精细化的结构随机地震响应,并分析这种相关性对结构响应的影响。结果表明:将地震动作用模拟为更接近实际的过滤高斯白噪声过程时,地震作用相关性对结构响应的影响更为明显,更为不可忽略。

     

    Abstract: Seismic action is generally decomposed into horizontal motion components and vertical motion components. Under the action of these two motion components, external excitation and parametric excitation processes may be experienced when the structure undergoes large deformation. Although these two incentive processes are completely related, it is often assumed that the two incentive processes are completely independent in the past research in order to simplify the analysis. A single-layer frame structure is studied. The correlation between external excitation and parameter excitation is considered, and a more accurate structural random seismic response is obtained. The influence of this correlation on the structural response is analyzed. Starting from the vibration equation of the structure, the cumulative moment truncation method is used to solve the non-stationary seismic response of a single-layer frame structure under the excitation of Gaussian white noise and filtered white noise. The results show that when the simulated ground motion is closer to the actual Gaussian white noise process, the influence of seismic correlation on the structural response is more obvious.

     

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