The Topological Dynamic Optimization Of Damping And Undamped Structure Based On Bi-deriction Evolutionary Structural Optimization

In the study of vibration and noise reduction of engineering structure,the way of additional damping materials has been widely used,the engineering structure has different performance requirements,too rigid optimization of the target may not be able to get the optimal damping material laying layout;and structural materials And the quality of the special requirements of the engineering field,the original structure itself,the search method can not be ignored.Based on the above problems,this paper proposes the optimal topology optimization algorithm of constrained damping structure and no damping structure under different optimization objectives.The outline of the analysis is as follows:(1)Through the development of BESO(Based on Bi-deriction Evolutionary Structural Optimization)in structural topology optimization,the superiority of this method in structural topology optimization is expounded,and the existing drawbacks of the algorithm are summarized.The method of bi-directional progressive method to optimize the topology of the optimal topology makes it efficient,but it is easy to update suspended in the process.Based on the above problems,a new definition of cell deletion rate and rate of addition in structure optimization process is proposed,which effectively suppresses the oscillation cycle and further improves the optimization efficiency.(2)Based on the principle of virtual work,the finite element model of constrained damping structure is constructed,and the modal parameter expression of constrained damping structure is deduced and the sensitivity formula of modal damping ratio and modal loss factor are solved.And the modal damping ratio of the result configuration is improved,and the optimization process is smooth and no oscillation.The amplitude of the modal parameters under different algorithms and the rationality of the result configuration are verified.The effectiveness of the improved bidirectional progressive method.(3)The kinetic finite element model of the undamped structure is constructed,and the vibration differential equation of the damped structure is deduced.The modal parameter expression of the damped structure is obtained and the frequency,displacement and stiffness sensitivity formula are solved.A multi-objective topology optimization model with minimum optimization target,structural natural frequency constraint and displacement constraint as the constraint condition.By using the improved two-way asymptotic optimization algorithm,the first three frequencies of the damped structure are improved,and the frequency curve of the topology configuration under the frequencyconstraint is smooth and the frequency constrained target is realized.The algorithm is applied to the multi-Optimization of effectiveness.