Research On Mechanical Products Dynamic Performance Modeling, Analysis, Optimization And Application

Dynamic performance is a important performance characteristic of mechanical products .About modern complex ,high speed ,heavy load, precise mechanical system, dynamic performance is a important factor to determine working performance behavior .Based on mechanical dynamics ,with mechanical dynamics design theory and three supporting techniques : finite element method(FEM) technique , experiment model analysis(EMA) technique and structure optimization technique, the dynamic performance analysis and optimization theory system was researched in the paper. Based on the theory, following works had been achieved:To the new large module curved-tooth bevel gear generator, a dynamic performance analysis theory system that combined FEM, EMA and dynamic response analysis was proposed. Based on FEM, and certified by EMA, the dynamic characteristics of the machine were analyzed, and the finite element model was fixed. With the dynamic response experiment, the dominant resonance modes, the dominant resonance frequencies and the spectrum characteristics were obtained.Based on the dynamic performance analysis theory, with structure optimization method ,three primary structure optimization principles for machine tools were put forward .By variation analysis method ,to the relation of machine tool column between dynamics performance and structure shape form and parameter was researched .The actual curved-tooth bevel gear generator column were optimized ,and its dynamic performance increased 10%.For typical cantilever example, the influence of structure model characteristic by vertical constraint stiffness, rotational constraint stiffness and above two constraints stiffness in the fixed end was analyzed. The first three"constraint stiffness-nature frequency"relationship curves, surfaces and polynomial functions were obtained, and the errors of which were less than 2% by finite element method. In the actual applications, model analysis errors were less than 1.5%, and in reverse application constraint stiffness identification average errors were 5%.To the piecewise stiffness mechanical vibration system, a method of confirming amplitude——frequency characteristic by working condition excitation was proposed. To the typical equipment-the nonlinear resonance screen, the stiffness of key elastic cell and the nature frequency characteristic of linear section was tested and researched. Using the working condition excitation method, the amplitude-frequency curves, the synchronism and the frequency element of several test points were tested and analyzed.To analyzing and optimizing the large vibration equipment, a universal meaning multi-body three-dimensional space all degree of freedom dynamics model with elastic connection elements was built. Applying the dynamics model to analyze nonlinear resonance vibration screen, the nature frequency characteristic of linear section and the amplitude and movement locus on several points were analyzed, and the amplitude-frequency characteristic curves were simulated, and the maximum amplitude-frequency value and the reason of odd frequency multiplications generation were obtained , and the results of above conformed to the test results. Moreover, to the new working condition, the design parameters of the nonlinear resonance vibration screen were optimized.