GRID MODEL STRUCTURE OF THE EXPERIMENTAL STUDY OF MODAL ANALYSIS

Experimental modal analysis is the integrated use of linear vibration theory,dynamic testing technology,digital signal processing and parameter identification methods,the system identification process.Modal analysis is an effective structure monitoring and safety assessment method,which is based on measurement of modal parameters(natural frequencies,damping ratios,mode shapes,modal stiffness,modal mass)relative to the normal changes resulting.And through correlation analysis and identification to determine the structural safety of an advanced method.This article describes the theory of modal analysis,and the grid model the structure of experimental modal analysis of the experimental modal test in the practical application of methods and means to identify the modal parameters of the system and with the finite element analysis were compared.Finite element results with the measured frequency has some different,but the difference percentage of first four modal frequencies is less than 9%,indicating that the measured results with finite element simulation is more consistent.