On The Compressive And Fracture Properties As Well As Finite Element Analysis Of Aluminum Foam

The compressive mechanical property and fracture toughness of aluminum foam are of great reference value in the practical application.By means of experiment and finite element simulation,this paper aims to study the compressive mechanical property and fracture toughness of aluminum foam which is utilized by industrial sector.The compressive experiments for two kinds of aluminum foams that are from industry and laboratory was conducted,the results showed that the elastic modulus,yield stress and energy absorption properties of aluminum foam were obtained.ABAQUS software was used to simulate the deformation of aluminum foam specimens.The constitutive equation is verified and the deformation process of aluminum foam in quasi-static compression process is analyzed.Based on the J integral theory,the value of aluminum foam is measured and calculated and the fracture toughness of aluminum foam is evaluated.The fracture process for aluminum foam is carried out by ABAQUS software,we calculated the area affected by the crack tip.The main conclusions are as follows:(1)XRD and SEM results showed that the main phases in aluminum foam specimens are Al-Ca-Ti compounds?small amount of Al-Ca compounds?Al20CaTi2?Al4Ca?Al-Ti compound and ?-Al.(2)The quasi-static compressive stress-strain curves of aluminum foam are divided into elastic region,platform segment and compaction zone.The porosity of the aluminum foam prepared by industrial production changes from 84.13 percent to 77.84 percent,and the elastic modulus,collapse stress and 50%strain energy absorption increase from 135.32,4.66 MPa and 2.08 MJ/m3 to 286.31,11.79 MPa and 5.14 MJ/m3 respectively.According to the analysis,the compressive mechanical property and energy absorption property of aluminum foam are negatively correlated with the porosity of aluminum foam and positively correlated with the density of aluminum foam.(3)According to the order of the whole specimen,single deformation band and single cell model,I initiate the quasi-static compressive simulation to aluminum foam,verifying the deformation mechanism of aluminum foam during compressive.The deformation band of aluminum foam is localized in the compressive process,and the deformation of the foam cell is accompanied by the buckling of the hole wall and the formation of plastic angle.(4)The single sample test method of three point bending specimen is used to measure the fracture toughness of aluminum foam based on the J-integral theory.Through the analysis and calculation of the JR-resistance curve,it concludes that the J1C value of foam aluminum is 0.204 kJ/m2,and the K1C value is 7.79 MPam0.5.(5)I stimulate two 2D models,which are 45×30 mm 2D solid fracture model,and 180×40 mm 2D three-point bending model.The area of 2D solid model affected by fracture stress is 2.48 cm2,accounting for 18.4percent of the total area.Moreover,there are 62 holes that are affected by fracture,accounting for 19.7percent of the total holes.In the 2D three-point bending model,the longitudinal length of the crack extending out of the plastic zone is 4 mm.There are 2 holes in the longitudinal extension line of crack in plastic zone affected by fracture.