Design And Optimization Of Sandwich Thin-walled Structures For Impact Resistance

With the rapid development of engineering technology,the requirements for the performance of protective structures in industrial technology are increasing.The thin-walled structure has been widely used in the field of protection and energy absorption because of its lightweight and strong energy absorption capacity.To further improve the mechanical properties of thin-walled structures,this paper proposes a design method of the sandwich thin-walled structures with the corrugated sinusoidal core and four types of sandwich thin-walled structures,triangular,quadrilateral,hexagonal and circular,are proposed based on the above method.Experimental validation,numerical simulation,theoretical analysis,and multi-objective optimization are used to explore the mechanical properties of the sandwich thin-walled structure and the main research contents include the following two aspects:(1)Study on the axial impact resistance of sandwich thin-walled columns.The axial impact resistance of three types of sandwich columns with sinusoidal corrugated core tubes,namely triangular,quadrangle,and hexagonal,were investigated.Firstly,the mechanical properties of sandwich columns with different parameters are investigated by experimental verification and numerical simulation.and it is found that the reasonable increase of the amplitude parameter A and period parameter N of the sinusoidal corrugated core tube can effectively improve the energy absorption of the sandwich column.Furthermore,a theoretical prediction model of the mean crush force under the axial loading of the sandwich column is derived based on simplified super folding element theory and the accuracy and reliability of the theoretical model are verified by experimental and simulation results.Finally,based on the orthogonal test design method,the optimal parameter configuration of three types of sandwich columns and energy absorption characteristics are obtained based on discrete optimization.(2)Research on the bending impact resistance of sandwich thin-walled beams.By varying the arrangement of the sinusoidal corrugated core tube,sandwich beams were introduced with both horizontal and vertical arrangements of the corrugated core tube,and the bending mechanical properties of sandwich beams with three configurations,namely quadrilateral,hexagon and circular,were investigated.Firstly,the bending properties of the sandwich beams with different A and N arrangements were investigated using finite element analysis.It was found that the quadrilateral sandwich beam had the strongest energy absorption capacity and the vertical arrangement of the corrugated core tube was more favorable to the energy absorption of the sandwich beam.Then,the sandwich beams with different parameters of the vertical arrangement of core tubes were ranked by using the technique for order preference by similarity to an ideal solution,and the sandwich beams with the best collision resistance performance were selected and subjected to three types of gradient designs in terms of thickness,amplitude,and period,and it was found that all three types of gradient designs could improve the bending mechanical properties of the sandwich beams.Finally,the wall thickness of the quadrilateral sandwich beam is optimized using the RBF approximation models and the multi-objective particle swarm optimization algorithm to obtain the thickness parameters of the quadrilateral sandwich beams with the optimum energy absorption characteristics.