Study On The Dimensional Variation Law Of Thin-walled Aluminum Alloy Rings

In the field of aviation,the aluminum alloy casing is an important supporting component of the engine,and its dimensional ac curacy is of great significance to the proper functioning of the parts.In this paper,after obtaining the modified constitutive model and damage model parameters of ZL114 A aluminum alloy,the key parts of the casing part is simplified to a ring part,and the influence of ambient temperature on the size change of the thin-walled ring part is analyzed.The main research contents are as follows:(1)The corresponding tests of amount round rods and rings of different sizes are conducted at different temperatures(17～25),which aim to measure the size values.According to the experimental data of the round rods,the mathematical model of the thermal expansion coefficient of the ZL114 A aluminum alloy is established,which effected by the temperature and the rod length.According to the experimental data of the rings,the factors affecting the size deformation of the ring are analyzed and discussed.The mathematical model indicating the relationship between the size deformation of the ring and the factors is established,and compared with the traditional thermal deformation formula,which provides the basis for thermal expansion studies of parts.(2)Quasi-static tensile tests and SHPB and SHTB tests are conducted on ZL114 A aluminum alloy to obtain its stress-strain relationship under high strain rate.The least squares method is used to calibrate the JC constitutive model.The original constitutive model is modified considering the coupling effect of strain and strain rate,and the predictive values of the different constitutive models are compared with the experimental values.Tensile tests are conducted on the notched specimen to discuss the effect of stress triaxiality on material failure,and the JC damage model at different strain rates is established.(3)The modified constitutive model program is writed and embed into the finite element analysis software.The axisymmetric finite element model for simulating quasi-static tensile tests and dynamic compression tests are established immediately.The results are compared with the experimental values to verify the accuracy of the simulated model and subroutine,which provides a basis for subsequent numerical simulations.(4)Aiming at the problem that the software can not accurately simulate the inner diameter deformation of ring parts,a simulation analysis model considering residual stress and ambient temperature is established.The residual stress after the machining of the part is obtained through the cutting simulation model,and the thermal-mechanical coupling analysis model is established in combination with the shape constraint load.The dimensional change of the inner diameter of the ring is obtained and compared with the actual results to prove the effectiveness of the simulation model.