Experimental study on constitutive model of high-strength aluminum alloy 6082-T6

Material constitutive relationship is one of the basic problems for analysis and application of aluminum alloy structures. This paper systematically studied the material constitutive model of the domestic high-strength new grade aluminum alloy 6082-T6. Tensile testing was conducted for a total of 90 coupons that were cut from three cross-section shapes of the aluminum alloy 6082-T6. The measurement and statistical analysis of mechanical parameters were carried out, including non-proportional extension strengths, tensile strength, elastic modulus, breaking elongation, Poisson's ratio, etc. Various methods for calculating hardening exponent n in the Ramberg-Osgood law were discussed. The fast simulated annealing (FSA) method for calculating n was proposed and the FSA code was written to obtain the confidence interval of n. Comparison of results between FSA and other methods indicates that the FSA can provide more stable results than the traditional two-point method. On this basis, the material constitutive model of the 6082-T6 aluminum alloy was obtained. The comparison of this model and the tested stress-strain curve demonstrates that the constitutive model has good accuracy and can be applied to the engineering applications of aluminum structures.