Constitutive model of structural aluminum alloy under cyclic loading

This paper investigates the hysteretic behavior of aluminum alloy by means of experimental study and theoretical analysis. Three different cyclic loading cases, including cyclic ascending, cyclic alternating and cyclic tensile were adopted for the 6082-T6 and 7020-T6 aluminium alloys. The failure modes, stress-strain curves under monotonic and cyclic loading were obtained. The test results indicated that the 6082-T6 and 7020-T6 aluminum alloy materials have good hysteretic behavior and the ductility of 7020-T6 is weaker than that of 6082-T6. Subsequently, the expressions of monotonic tensile curves, hysteretic curves and skeleton curves were fitting based on the piecewise Ramberg-Osgood model. Finally, the uniaxial hysteretic constitutive model regarding Chinese aluminum alloy was proposed. The test data were used to validate the reliability of the proposed hysteretic constitutive model. The results showed that the uniaxial hysteretic behavior of Chinese aluminum alloy can be accurately described by the proposed model.