Counter Viscous Pressure Forming And Parameter Optimization Of Aluminum Alloy Hemispherical Parts

Aiming at the large deformation,wrinkling and cracking of aluminum alloy hemispherical parts,a method of counter viscous medium pressure forming of aluminum alloy hemispherical parts is proposed based on viscous medium pressure forming and reverse liquid filling.The forming process uses the counter pressure of the viscous medium to improve the stress state and formability of the hemispherical part,thereby providing a new method for the forming of such parts.Firstly,the forming limit experiment of the LF2 aluminum alloy sheet was carried out.The ultimate strain data in the sheet surface under different strain paths were obtained and the forming limit diagram of LF2 aluminum alloy sheet was established through the hemispherical rigid punch bulging experiment on samples with different width.And it can provide a reliable criterion for the finite element analysis and experiment of the counter viscous media pressure forming of aluminum alloy hemispherical parts.Secondly,the ANSYS/LS-DYNA was used to simulate and analyze the counter viscous medium pressure forming process of the aluminum alloy hemispherical part.The forming process and the distribution of stress-strain and wall thickness of the formed specimen under the conditions of different counter viscous medium pressure and loading path are obtained.On this basis,the process parameters of counter viscous medium pressure forming are optimized.Finally,the counter viscous medium pressure forming experiment of aluminum alloy hemispherical parts was carried out,and the deformation law,wall thickness distribution and quality problems of aluminum alloy hemispherical parts under different counter pressure conditions were given.The accuracy of the finite element analysis results is verified,and qualified parts are formed under the optimized counter viscous medium pressure loading conditions.