Research On Envelope Forming Method For Thin-walled Cylindrical Components With High Ribs

Thin-walled cylindrical components with high ribs are widely used in transportation,energy,aerospace,defence-related science and technology owing to its lightweight,high stiffness and high bearing capacity.The features of thin-walled cylindrical components with high ribs such as thin wall,high and grid-like ribs make manufacturing thin-walled cylindrical components with high ribs difficult.At present,the traditional methods of manufacturing thin-walled cylindrical components with high ribs mainly include casting,cutting and welding.However,the traditional forming methods for thin-walled cylindrical components with high ribs have some limits such as low material utilization,low component performance and low production efficiency.In order to realize the highperformance,high-efficiency,and low-cost manufacturing of thin-walled cylindrical components with high ribs,an innovative envelope forming process for thin-walled cylindrical components with high ribs was proposed in this paper,and it was researched by theoretical calculation,finite element simulation,experiment as follows:The forming principle of thin-walled cylindrical components with high ribs was put forward,and the geometry and kinematic model of envelope forming for thin-walled cylindrical components with high ribs were established.Based on proposed geometry and kinematic model,the accurate design method of enveloping roll was proposed,which realizes non-rotating thin-walled cylindrical components with high ribs being formed by rotating envelope forming processing.The interference determination criterion between the enveloping roll and thin-walled cylindrical components with high ribs was proposed,the enveloping roll correction model was established,and the enveloping roll modification method was proposed.The simulation and experiment of the envelope forming for thin-walled cylindrical components with high ribs were carried out and it was testified that the proposed design method and modification method of enveloping roll are promising.The static and plastic mechanical models were established for envelope forming for thin-walled cylindrical components with high ribs,stable forming condition of envelope forming for thin-walled cylindrical components with high ribs was derived,and critical friction coefficients were obtained.The comparison of the theoretical calculation results with the finite element simulation results shown that the stable forming condition proposed in this paper was reliable.Based on the results of finite element simulations,the filling of high ribs,equivalent stress field,equivalent strain field,metal flow rule and forming load change rule in the process of envelope forming for thin-walled cylindrical components with high ribs were further analyzed.And finite element models of envelope forming for thin-walled cylindrical components with high ribs under different process parameters were established.The effects of the feeding speed,friction coefficient and diameter of the enveloping roll on the filling of high ribs,equivalent strain distribution,metal flow velocity,damage factor and maximum forming load in the process of envelope forming for thin-walled cylindrical components with high ribs were researched in detail.