Large-scale Structure Of Experimental Modal Analysis Method And Software Development,

The development trend of mechanical products is high-speed, high-precision and portability, which makes the problem of vibration and noise more and more severe. So the technique of improving system performance attracts more attention. One of the main means to improve the performance of products is dynamics study, which plays a quite important role in product designing. Experimental modal analysis is such a method which provides a base for amending system structure by extracting system modal parameters from experiment.On the basis of the theories of modal analysis as well as analyzing the character of experimental modal analysis on large structure, a new global curve fitting method is proposed through the comparison of some identifying modal parameter methods, which applied the experimental modal analysis on large structure. In the integrative development environment of Visual C++, choosing the Matlab tools of mathematics, the arithmetic program is designed anddeveloped, and the software of kernel step on experimental modal analysis-identifyingmodal parameter is completed, which supply the feasible basis for the development of analysis software system of experimental modal.Based on lucubrating the basic theories of experimental modal analysis and analyzing the current research on corresponding software both at home and abroad, a experimental modal analysis software system is studied and developed with OpenGL technology and the tools of Matlab founding on the system platform of Windows.According to the general status of structure, through the measure of force and response, the frequency response function is acquired in practical application. The modal parameters of modal frequency, damp, mode shape and so on are identified with the global curve fitting method, which supply the credible causes for following dynamic optimized design. At the same time, drawing simply the three-dimensional model of structure is completed by using OpenGL technology, which shows the weak points of structure to us through the display of structural mode shape using three-dimensional animated technology.At last, the process and method applying the system is proposed and the notices of experimental modal analysis is summarized by a practical case of experimental modal analysis on a structure. The result is coincided with the modal analysis software of B&K company, which indicates that the software system can be used in experimental modal analysis on large structure and the result is correct, which proves it supplies the credible causes for dynamic optimized design.