Transient numerical simulation on the surface deformation for GAE forming of plastic micro-pipe

Abstract

To ascertain the mechanism of gas-assisted extrusion (GAE) deformation for the plastic micro-pipe (PMP), the transient simulation was done. The geometric model based on three phase fluids and finite element mesh were established. To get the converge solutions, the Crank-Nicolson integration, the interpolation method of elastic-viscous split-stress finite element method combined with streamline-upwind scheme were used. At the reasonable boundary and material conditions, the GAE forming of PMP for different gases flow rates were numerically studied. Moreover, the extrusion profiles of PMP under different transient times were also obtained. To explain the reason of surface deformation for the GAE forming of PMP, the radial and axial velocity, and stress difference of melt under larger gases flow rates at different transient times were all obtained. The transient numerical results can better interpret the mechanism of surface deformation of PMP.