Finite Element Analysis And Experimental Study On Thermal Deformation Of Aluminum Alloy Ring Parts

The aeroengine is a thermomechanical part that integrates complexity and precision.Under the working state of the aeroengine,the casing is affected by the inertial force and the external air pressure,as well as the thermal load caused by the temperature difference.And the casing is a key bearing component of the entire aeroengine device.For the large-size light alloy ring-shaped casing part,its processing is complicated,its material removal amount is large,and its processing time is long.The cutting heat generated by the machining process and the change of ambient temperature will cause the accuracy of the produced parts to be substandard.In this thesis,the casing is abstracted as the ring.The detailed research has been carried out on the thermal deformation of the ring part itself.The change rule and the influence degree of thermal deformation are explored through theory,simulation and experiment,which can be used as a reference for improving product qualification rate and machining efficiency,and reduce production cost of the casing.The main research contents of this thesis are as follows:(1)The thermal deformation of the aluminum alloy ring part under different temperature fields is studied.Based on the basic theory of thermodynamics,the theoretical solution formulas of the radial thermal deformation of the ring under the steady uniform temperature field and the steady non-uniform temperature field are derived.The theoretical results are compared with the finite element thermal deformation simulation results under these two temperature conditions.The result shows that the traditional thermal simulation analysis method of steady-state uniform temperature field cannot reflect the non-similarity characteristics of the thermal deformation of the parts.(2)The ZL114A aluminum alloy rings are chosen as the research object,and the thermal deformation simulation method based on conversion of heat into force is proposed.Experimental study on the thermal deformation of aluminum alloy rings of different sizes at different ambient temperatures is carried out.The change rule among radial thermal deformation and inner radius,outer radius,wall thickness and temperature difference is explored.The multiple regression fitting analysis is carried out on the thermal deformation test values.The multiple regression fitting results and the simulation results are compared to verify the correctness of the thermal simulation model.(3)Taking the two-dimensional model of ZL114A aluminum alloy parts as the simulation object,the temperature distribution of the surface layer and the deep layer of the workpiece under the moving heat source model and the orthogonal cutting model are compared and analyzed.The results show that the moving heat source model has the same temperature simulation effect as the orthogonal cutting model.It provides support for the subsequent thermal deformation simulation research of the aluminum alloy ring parts under local heating.(4)The inner diameter?278.85₀^+0.032of ZL114A ring part is chosen as the simulation object.Based on the moving heat source model,the temperature field distribution and the radial thermal deformation displacement field distribution of the surface layer of the workpiece are simulated.The law of the thermal deformation is explored.It provides important reference and guidance for the elimination of thermal errors in the processing of precision parts such as the casing.