Study On Dynamic Mechanical Properties And Cutting Model Of Anisotropic Aluminum Alloy

Aeronautical aluminum alloy is widely used in high-end equipment of aerospace.Before it is finally formed,the aluminum alloy plate should be conducted through several forming processes such as rolling,pre-streching etc.Because of these forming processes and the different components added,there will be great differences in the structure of the matrix formed,which will cause complex effects in the actual processing and application process.High speed cutting is commonly used in the aerospace industry with high material removal rate and high quality.Compared with traditional cutting,the higher cutting speed shows more obvious characteristics such as high local strain rate,large strain,instantaneous high temperature and material embrittlement in the material cutting deformation zone,which will increase the difficulty of building accurate description of material mechanical properties.Due to the limitations of test methods and modeling methods,the constitutive model of materials is not suitable for high-speed machining,which directly affects the cutting accuracy of aerospace high-speed aluminum alloy.In this paper,anisotropic 7050-T7451 aluminum alloy is used as the research material,focusing on different dynamic mechanical behaviors of aluminum alloy sheet under dynamic loading of different orientations(rolling direction,normal and transverse).Through studies on the workpiece deformation data of dynamic mechanical performance,cutting force and temperature under dynamic loading,with the help of material experiments,cutting experiments and numerical simulation as well,the constitutive model of materials which can preliminarily show anisotropic is established respectively.The samples prepared along the rolling,normal,transverse directions of 7050-T7451 aluminum alloy plate was conducted under the Hopkinson pressure bar experiment at room temperature.After that,the dynamic mechanical properties of these three oriented samples were analyzed as well;The J-C constitutive parameters of three orientations were established with experimental data.The results were input into the DEFORM 3D finite element software,and the dynamic impact compression finite element model was established.The numerical simulation and experimental results was compared.As a result,the validity of the obtained constitutive parameters was verified.Based on the Oxley orthogonal cutting theory,high speed orthogonal cutting experiment of three kinds of orientation sample was conducted with focus on analyzing the experimental cutting force,cutting temperature and shear angle in different cutting speed and feed speed.Oxley orthogonal cutting ? model and J-C constitutive model are combined.With the experimental data results of three oriented samples and the orthogonal cutting inverse method,the material orientation parameters obtained by Hopkinson pressure bar experiment are modified.Finally,the J-C constitutive para meters under high speed cutting conditions are obtained.By introducing the high speed cutting constitutive parameters into the AdvantEdge FEM cutting software,the two-dimensional finite element model of high speed cutting was established.And the numerical simulation of high-speed cutting process was carried out,and the data change rule of cutting force and cutting temperature in the process was analyzed emphatically and compared with the experimental results.At the same time,the effect of material anisotropy on the cutting properties of the material was analyzed.The results showed that the established material model can meet the requirements of high speed cutting process simulation and ensure accuracy.