Studies On The Properties Of Closed Cell Aluminum Foam And Its Application Based On The Control Of Pore Structure

Closed cell aluminum foam is a new class of porous metal materials,which has a broad application prospects in the field of modern aerospace,automotive industry and transportation by virtue of its characteristics of high specific stiffness,high specific strength,light weight and impact energy absorption.According to the geometric modeling issues of closed cell foam,the aim of this paper is to establish a geometric model with high porosity,uniform pore distribution and adjustable cell wall shape,providing geometric modeling of closing to the actual situation for compressive test and impact energy absorption.Based on this foundation,the paper had studied the impact simulation of bumper filled of closed cell aluminum foam.The main research contents are as follows:(1)A 2D random round model with uniform distribution and adjustable pore wall structure of the foam material,and a 2D Voronoi random model and a 3D Voronoi random model with adjustable cell wall shape were established by utilizing the Matlab platform.In addition,an optimization algorithm for the geometric model of foam cell is proposed.The cell wall shape control equation is proposed by controlling the cell wall shape of the Voronoi polygon centered on seed points.(2)The closed-cell aluminum foam model with different pore structure were established based on the optimization algorithm of the geometric model of foam cell.Through compressive deformation numerical simulation in ABAQUS,the effects of the size of simple,porosity,the size of hole,the rate of loading and cell wall shape on the stress-strain curve and energy absorption were obtained.Through the compressive deformation numerical simulation of an entity that is given the mechanical properties of foam aluminum,the accuracy of this method is confirmed.(3)Cutting the foamed aluminum material with different porosity by a wire cutter,and the compression test was carried out on the microcomputer control electronic universal testing machine.The stress-strain curves collected are compared with the finite-element analysis results,which turns out be approximate then the reliability of finite element simulation is verified.In addition,thronging the analysis of the simulation results under different speed,confirmed the strain rate within a certain unit does not have the strain sensitivity.(4)Using SolidWorks modeling on the bumper that filled with closed-cell foam aluminum,give the property of good energy performance model material to full filled entity,avoid large deformation problems for the internal complexity of foam aluminium geometric.Taking the collision impact simulation to filled and unfilled bumper respectively based on LS-DYNA platform,and analysing the impact of aluminum foam filling body to the bumper beam energy performance.The optimization model of foam cell geometry model can be applied to the establishment of foam metal model.At the same time,the foam aluminum can effectively improve the energy absorption of the bumper,so as to better protect the safety of passengers.