Research on Building Structure Modal and Finite Element Modeling Based on Natural Environment Excitation
Through the field measurement and random vibration analysis of high-rise buildings under environmental excitation, the obtained modal information such as frequency and mode shape is of great significance for the dynamic performance evaluation and seismic design of high-rise buildings. This paper introduces the high-rise building dynamic test project, systematically tests the random vibration signals of 8 high-rise building structures, obtains the cross-power spectrum of the structure through cross-correlation function analysis and Fourier transform, and obtains the step-by-step test by setting the reference point. The working mode of the structure, in order to obtain important parameters such as the natural vibration frequency of the structural vibration. A high-rise building finite element model is built in PKPM software and Sap2000 software to obtain the calculated frequency and mode shape of the structural vibration. In order to study the influence of the stiffness and quality of the infill wall on the dynamic characteristics of the high-rise structure, three finite element models were specially established in the Sap2000 software. Through research, it is found that the fundamental frequency of the structure obtained by the test is more than twice the fundamental frequency of the commonly used design software PKPM. In addition, the shell element is used to simulate the shear wall stiffness and the quality of the infill wall can be accurately estimated. The measured modal value of the structure.