Parameter determination of constitutive relationship of 3004H24 aluminum alloy based on ductile damage model

Abstract

Under the action of long-term wind load, the aluminum alloy roof plates inevitably produce damage accumulation, and even fatigue failure. In order to develop the damage constitutive relationship of aluminum alloy and to study the structural response of roof plates under wind load, tests of 15 3004H24 aluminum alloy specimens were carried out under monotonic loading and many kinds of cyclic loading, and the cyclic loading tests were simulated based on the ductile damage model in ABAQUS. Firstly, the monotonic behavior, hysteretic behavior and macroscopic failure modes of the material were compared and analyzed based on the test results. The results show that the ductility of 3004H24 aluminum alloy is poor. The fracture of the specimen is very sudden and the fracture surface makes a 45° angle with the tensile stress direction. In the cyclic loading tests, there is obvious necking before the material is broken, and the stiffness degradation and strength degradation occur when the displacement reaches 1.25 mm. This indicates that the constitutive relationship of the 3004H24 aluminum alloy under monotonic loading cannot be used for fatigue analysis. In addition, the parameters of the ductile damage model under various cyclic loading were determined according to the agreement between the test curves and the numerical curves, and finally the general constitutive relationship of 3004H24 aluminum alloy based on ductile damage model was obtained by least square fitting. The constitutive relationship established in this paper provides a basis for the subsequent accurate calculation of the response of aluminum alloy roof plates under dynamic loads.