Hydrostatic extrusion is a manufacturing process in which a billet is completely surrounded by a pressurized fluid to force it to pass through a die of a certain shape and size. The key points of hydrostatic extrusion are:
No friction between the container and the billet.
Low friction between die and billet.
Low power consumption.
Usually increases the material's ductility as high pressure is applied.
Large ingots/billets with large cross sections can be extruded.
No residue of material left on the container walls.
In this problem, the extrusion of a polymer is analyzed. A cylindrical billet is deformed into a smaller radius long cylinder using a conical die. During the extrusion, the billet material exhibits large elastic and plastic deformation. The deformations are modeled via a multiplicative-decomposition-based finite-strain hyperelastic-plastic material model.
Mechanical APDL is used to simulate the hydrostatic extrusion, predicting both the deformed shape after extrusion and the stress and strain distribution.
Fluid-pressure-penetration loading is used to simulate the hydrostatic pressure for the extrusion process. The pressure-penetration load simulates surrounding fluid or air penetrating into the contact interface, based on the contact status. It acts as a load when the contact status is open and is replaced by contact pressure when the contact closes. The fluid-penetration-pressure-loading is path-dependent; therefore, a starting point for fluid-pressure application is either program-selected or user-defined.
For more information about fluid pressure-penetration loading and the starting-point selection, see Applying Fluid-Pressure-Penetration Loads in the Contact Technology Guide.