Study On Multi-pass Spinning For Thin-walled Aluminum Alloy Parts

In the multi-pass spinning,the core technology is the multi-pass spinning roller trajectory design.Due to lacking a correct evaluation method of wrinkling defects in spinning,the roller loading trajectory design,especially the determination of the number of passes,is still in the experiential trial and error stage.But,the period and cost of the test method are too high for large-scale components.It is necessary to use numerical simulation to realize the digital evaluation of roller trajectory.Therefore,in view of the flange wrinkling phenomenon in multi-pass spinning,based on the energy method,a prediction model for multi-pass spinning flange wrinkling is established,which realizes the accurate determination of the number of multi-pass spinning forming passes and provides technical guidance for the process design of multi-pass spinning trajectory.The main research results of this parper are as follows:1)Taking the second flange forming stage,the first flange preforming stage and the second flange preforming stage of aluminium alloy parts as examples,the flange wrinkling prediction models in non-first spinning stage and in flange preforming stage were established based on energy method.The numerical simulation model of multi-pass spinning process is realized by ABAQUS,which provides stress-strain field and geometric information for wrinkling prediction models.Realized the accurate prediction of flange wrinkling in multi-pass spinning and verified through spining tests.2)Multigroup spinning roller trajectory schemes for aluminium alloy hemispherical components were designed by combining shear spinning with general spinning.Based on the flange wrinkling prediction models in multi-pass spinning,the digital evaluation of the multi-pass spinning process for the aluminium alloy hemispherical component is completed,and the minimum number of process paths aiming at eliminating wrinkling phenomenon is found.The multi-pass spinning test shows that the multipass spinning process planning method for hemispherical components based on wrinkle model is feasible.3)The multi-pass spinning process scheme of fuel tank bottom parts with a diameter of 3350 mm for large launch vehicle is designed based on the multi-pass spinning flange wrinkling prediction models and the studies of multi-pass spinning roller trajectory of alloy hemispherical parts.The feasibility of the scheme in the first spinning stage and preforming stage was evaluated by the flange wrinkling prediction models and numerical simulation technology.The results show that the designed multi-pass spinning process has no wrinkling phenomenon in the first pass.The multipass spinning test of 625 mm diameter reduction parts has been completed,and the test results are consistent with the numerical evaluation.This result provides technical support for the trial production of the fuel tank bottom component.