地震荷载作用下海上电气平台动力模型实验

DYNAMIC MODEL TEST OF OFFSHORE SUBSTATION PLATFORM UNDER EARTHEQUAKES

基于水弹性相似律,完成相似比尺为1∶30的海上电气平台结构动力实验模型的设计。以实测地震动和人工合成地震动作为激励,开展不同地震波作用下的结构动力模型实验。运用ANSYS开展地震荷载作用下的结构动力时程响应分析。通过实验数据与有限元结果的分析对比得出,在较小地震荷载作用下,结构反应极值与地震峰值加速度之间表现为线性关系。随着地震峰值加速度的增加,水-结构的非线性效应不断增强,导致结构反应极值呈现出非线性变化趋势。因此在极端地震荷载作用下,水-结构的非线性影响不可忽略。由结构的频域反应可知,结构的频域响应与结构自身的动力特性和激励地震波的频谱特性密切相关。

Dynamic model of offshore substation platform is designed based on the hydro-elastic similarity,and the similarity scale of the model is 1∶30. Series of test cases are performed under the synthesized ground motion and the measured seismic excitations. A finite element model of the test model is established using ANSYS,and then the time history seismic analysis is performed. Based on the comparison of the experimental and numerical results,a linear relationship between the maximum structural response and the peak ground accelerations(PGAs)is found. It also should be noted that the nonlinearities of the fluid-structure interaction will influence the structural response at a higher seismic intensity. Therefore,in order to obtain a reasonable structural response,the fluid-structure interaction should be taken into account under extreme seismic loading. According to the structural response,the frequency domain response is closely related to the dynamic characteristics of the structure and the spectrum characteristics of the excitation seismic waves.