The Structural Optimization Design Of Composite Laminates Based On Reanalysis

Composite material has high strength,high stiffness,low density and other significant advantages.Therefore,it has been widely used in aviation,vehicle,ship and other fields.To optimize the design of composite laminates,the design variables of composite laminates need to be modified continuously to obtain better material properties.In the traditional optimization design of composite laminates,complete simulation analysis and calculation are needed for each modification of design parameters,which will greatly prolong the optimization design cycle.Reanalysis method is a method to use the information obtained from the initial structure analysis to quickly calculate the response of the modified structure,so as to avoid the complete analysis and solution of similar structures for many times,so as to improve the calculation efficiency.In order to solve the problem of low efficiency in the optimization design of composite laminated plate structure,this paper introduces the reanalysis method instead of the complete finite element simulation analysis to analyze and solve the modified structure quickly.The main research contents and conclusions of this paper are as follows:(1)According to the constitutive relation of single layer plate,classical laminated plate theory and first-order shear deformation theory,a composite laminated plate model is established.Based on the first order shear deformation theory,the finite element analysis and derivation of the laminates were carried out,which mainly included quadrilateral element coordinate mapping,stiffness and mass matrix calculation.The finite element analysis program was programmed with MATLAB,and the static analysis example of composite laminates was realized.Compared with the results of ABAQUS,the relative error was very small,which verified the accuracy of the program.The effects of different element sizes on the iterative convergence of finite element are also studied.(2)According to the basic theory of combinatorial approximation method and inverse iteration method for solving structural modes,the static analysis and modal analysis of the structure are carried out.The axial shifting method is introduced to improve the iterative convergence rate.The finite element modal analysis program and the reanalysis method program were programmed by MATLAB.Three examples were used to verify the accuracy of the program and the efficiency of the reanalysis method.(3)The differential evolution algorithm was used to optimize the structure design of composite laminates,and the new mutation strategy and mutation strategy selection method were introduced to improve the search ability and convergence rate of the traditional DE algorithm;Introduction analysis method to the differential evolution algorithm,instead of a complete finite element analysis method,improving the overall computational efficiency,studied the analysis method of base vector selection influence on calculation accuracy,at the same time in order to avoid the cumulative error results caused by inaccurate,after a certain number of iterations are a complete finite element analysis was carried out on the structure,in order to eliminate cumulative error;Two numerical example is used to compare the convergence rate and operation results of the adaptive differential evolution algorithm based on reanalysis and the differential evolution algorithm based on finite element method.It is proved that the proposed algorithm can improve the efficiency of structural optimization design of composite laminates.