Structures, such as bridges, pipelines which are supported at multiple places, will be subjected to differential excitation. A significant change in the correlation of the motions between the two supports is due to the combined effects of wave passage, coherency loss and local soil conditions. In the classical formulation, the response is divided into quasi-static and dynamic components and the latter is usually evaluated by time history methods or modal analysis for a linear system. In this work, the feasibility of Proper Orthogonal Decomposition (POD) vectors as a replacement for the conventional eigenvectors has been discussed. The performance of POD modes has been assessed for the uncoupled system, system having closely spaced modes. The null space vectors of the POD modes generated from the response of the structure subjected to correlated input motion were able to predict the responses of the structures subjected to spatially varying input motions. The efficiency of using the POD vectors has also been verified with the help of an experiment conducted on a steel control and safety rod drive mechanism (CSRDM) which is an example of multi-supported and differentially excited structure.

中文翻译：

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使用 POD 向量对遭受空间变化地震的结构进行地震分析：实验和分析研究

多处支撑的桥梁、管道等结构将受到差动激励。两个支撑之间运动相关性的显着变化是由于波通过、相干性损失和当地土壤条件的综合影响。在经典公式中，响应分为准静态和动态分量，后者通常通过时间历史方法或线性系统的模态分析来评估。在这项工作中，讨论了使用适当正交分解 (POD) 向量替代传统特征向量的可行性。POD 模式的性能已针对非耦合系统进行了评估，系统具有紧密间隔的模式。从受到相关输入运动的结构的响应产生的 POD 模式的零空间矢量能够预测受到空间变化输入运动的结构的响应。在钢控制和安全杆驱动机构 (CSRDM) 上进行的实验也验证了使用 POD 矢量的效率，该机构是多支撑和差动激励结构的一个例子。