A6C16 Dynamic Mechanical Property And Fracture Failure Analysis Of Aluminum Alloy For Automobile

Aluminum alloy sheet is one of the most critical materials in vehicle light-weight process,in the article,the A6C16-T4 aluminum alloy is selected as research object,and base on mass experiments,analysis how the strain rate affects flow stress of aluminum alloy and how stress triaxiality affects fracture failure of aluminum alloy.The main content is:First,in the article,base on the quasi-static uniaxial tensile test and dynamic impact tensile test the effect of strain rate upon dynamic mechanical property of A6C16 aluminum alloy is analyzed.The result shows: A6C16 aluminum alloy has remarkable plastic deformation capacity,and distinct strain rates have diverse influences on mechanical property in different strain rate range,and under the relatively lower strain rate(0.00033⁰.033s^-1)condition,tensile strength decreases in some degree as strain rate increases.Under the medium stain rates condition,the aluminum alloy shows positive correlation-as strain rate increases its tensile strength and yield strength also increases: as strain rate increases fracture strain also increase,and strain rate can improve the plastic deformation capacity,however,the fracture strength does not change too much.Base on Johnson-Cook simplified constitutive model,create stain rate relative plastic constitutive model of the aluminum alloy,finally by utilized LS-DYNA finite element software the numerical simulation of dynamic impact tensile experiment is conducted,and the simulation result match well with experimental result.Secondly,in the article,base on plate test,shear test,notch test and opening test,get the strain of 2mm gauge length in sample fracture location,it is analyzed how stress triaxiality affects fracture failure of aluminum alloy,moreover,the stress triaxiality of the above specimens are simulated by using finite element software.The results show: the state of stress on specimens has angreat effection on fracture failure of aluminum alloy A6C16.In shear test,stress triaxiality approaches 0;fracture strain could reach 95.17%,as the stress triaxiality increases fracture failure strain decreased,when the stress triaxiality is 0.48,the fracture strain decrease to the minimum value around 46.32%.Then,fracture failure strain increases again as stress triaxiality increase.At last,by utilized LS-DYNA finite element software the numerical simulations of above test are conducted,and the simulation result match well with experimental result.At last,in the article,it conducts the finite element simulation of notch,verifies material parameter by using LS-DYNA finite element software.The simulation result match well with experimental result,and the deformation process and fracture geometry of specimens are similar.The material parameters can be used in whole vehicle crash model directly.