Research On Anisotropic Plastic Constitutive Model Of 2219 Aluminum Alloy

With the development of modern industry and technological progress,the requirements of industrial components grow more stringent.As a high-quality industrial alloy,2219 aluminum alloy is partially better than steel in performance.Because of the low density of aluminum metal elements,2219 aluminum alloy mixed with other elements is light in weight and high in strength.2219 aluminum alloy’s related metal components used in industrial production can greatly reduce the mass of the object to achieve the goal of weight reduction,so 2219 aluminum alloy components are widely used in the field of aviation,such as the skin of the aircraft fuselage and so on.Therefore,this paper analyzes the mechanical properties of2219 aluminum alloy based on its application in real life,mainly studies the mechanical properties of the material in the stage of plastic deformation,and constructs its constitutive equation.The research contents are as follows:(1)2219 aluminum alloy plate is a typical anisotropic metal material.Due to the existence of the anisotropic properties of materials,there are certain differences in the mechanical properties of materials in different directions,and the anisotropy has a variety of manifestations.To accurately describe the anisotropy properties of materials,the relevant mechanical tests are carried out on specimens with different angles: 0° along the rolling direction,90° perpendicular to the rolling direction,30° to the rolling direction,45° to the rolling direction and 60° to the rolling direction.(2)Three test methods of uniaxial tension,uniaxial compression,and shear were designed in this paper.Digital Image Correlation(DIC)was used to monitor the deformation process of specimens under the three test methods.Image processing software obtained the true strain of specimens under the three test schemes.Considering the non-uniform deformation in the transverse and thick direction in the process of uniaxial tensile and uniaxial compression tests,the cross-section factor in the process of the test is calculated by using the formula,and then the true stress in the process of the test is calculated.(3)According to the true stress-strain curve,the translation strain method is used to calculate the yield stress of materials at different angles using different test methods.Based on the true stress-strain relationship,the anisotropy of the material is verified and the properties of tension and compression asymmetry are found.(4)The Voce hardening model was constructed by using the true stress-strain curves of different test methods.By comparing Hill48’s yield criterion and Drucker’s general yield criterion,Drucker’s general yield criterion is selected as the yield criterion of this paper.Through the analysis of Drucker’s general yield criterion,the anisotropic parameters of the yield criterion were calibrated by using the data of different experimental methods and angles.(5)Using the principle of equivalent plastic work,the plastic work under the three test methods was achieved,namely,the graph area of the true stress-true strain curve.Taking the shear test state as the equivalent stress state of the material,the equivalent plastic strain and equivalent stress of uniaxial tension and uniaxial compression could be calculated respectively.The subsequent yield surface and anisotropy parameters related to yield function are obtained by using equivalent stress and equivalent strain.