Optimization Design Of Constrained Damping Structures Based On Topology Optimization Method

With the development of modern industry in China,energy saving and environmental protection requirements of products in the industry have taken more and more important place,and lightweight has gradually become a significant link in product design.Plate and shell structure can bear very huge load force with asmall weight,but the problems of vibration and noise of plate and shell structure have increased sharply,which directly affect its safety and life.This article mainly with viscoelastic constrained damping structure as the research object,based on the homogenization theory put forward a kind of viscoelastic constrained damping structure topology optimization method,provides a new method to suppress the vibration of the plate and shell structure and increase the utilization rate of viscoelastic damping materials,the paper research content mainly has the following several aspects:First of all,based on the elastic constitutive relation and viscoelastic constitutive relation to establish viscoelastic finite element model of constrained damping plate unit cell,this study considers the effect of boundary representative volume element method to deduce the equivalent stiffness matrix of viscoelastic damping layer and the equivalent mass matrix,and compared with the traditional finite element modeling method to get the inherent frequency.The correctness of the fine-macro dynamics modeling method is verified.Secondly,this study has optimized the viscoelastic constrained damping structure as the optimization goal of maximizing macroscopic modal loss factors of viscoelastic constrained damped structures,at the same time,it has set up the constraint damping structure of viscoelastic damping layer mesoscopic structure topology optimization model and optimization objective function has been deduced on the sensitivity of design variables,then the optimization criterion method is adopted for solving mesoscopic topology optimization model;After that,the cooperative topology optimization model of viscoelastic damping layer and macroscopic structure of constrained damping structure has established.When the sensitivity analysis of its fine and macroscopic structure was completed,the optimization criterion method was used to solve the problem to obtain the meso-topological configuration and macroscopic topology configuration of constrained damping structure.Finally,it makes the experimental sample of constrained damping structure with topology optimization configuration has been made,and builds the LMS vibration testing platform,comparing the natural frequency of the experimental sample from the modal experiment with the natural frequency of the experimental sample from analysing numerical.By the amplitude-frequency response diagram of experimental sample obtained by hammer test samples,it can be seen that laying topology optimization configuration of constrained damping plate on viscoelastic damping materials to reduce,meanwhile,it still has a good vibration damping performance.Topology optimization algorithm proposed in this paper in the process of optimization of the constraint damping structure has a guiding significance,which is verified by experiment.