Processes Simulated by QForm

Hot / Warm closed die forgingOpen die forging / coggingFasteners / HeadingCold forgingExtrusionReducer RollingCross Wedge RollingRing RollingTrimming /Piercing /ShearingElectric UpsettingPowder FormingHydroformingHeatingMicrostructureHeat TreatingDie / Tool Simulation

Die / Tool simulation

QForm can show die stress on the surface of the die and internally in both 2D and 3D tool simulations.

A tool simulation can be run where the user can see the following properties in the tool:

It is useful to see the effective stress values in your tools to be sure that you are within the yield strength of your tool steel. If you exceed the yield strength of your die steel you will encounter localized plastic deformation in those areas of your dies that will quickly lead to failure. Elevated values of effective stress should be avoided.

Example of die stress simulation benefits

In the following example a forge die for a gear with finish-forged teeth for a PTO Application was cracking after around 400 parts. Improvement was needed for production quantities.

Close up of die crack

Simulation showed local elevated levels of stress where the die was cracking

The problem is solved by separating the die into two parts with the use of an insert so that the die can move freely eliminating the high stress in this area.

Shrink rings

It is very easy to see the effects of a shrink ring on both 2D and 3D tool simulations.
The dimensions and fit of the shrink ring can be easily adjusted to find the optimal values.

Effective stress without shrink fitting

Effective stress with shrink fitting

Die wear

QForm can show a relative die wear factor across the surface of the die. This will graphically show the areas on the die with the most wear and the areas on the die with the least wear.

Die wear factor on die surface

Example of die wear simulation

In this cold headed bolt, the original design yielded a defect free trimmed bolt in four stations.

However the top die cut the workpiece in the third station creating a lap that was later trimmed off.

This created uneven die wear factors on the top and bottom dies

Maximum die wear factor of 20.78 on the top die and 2.8 on the bottom die.
This means that the top die would wear out almost ten times faster than the bottom die.

The design was modified to have more even material flow in three stations

Now there are more even values of die wear on the top and bottom dies (7.28 and 9.9) and the die set will last much longer.

Die deflection

QForm can show die deflection based on the forging loads applied through the workpiece in both 2D and 3D simulations. This allows the user to see where the forces are greatest within the tooling. A magnification factor can be applied to make the deflection more visible.

die deflection in 3D tooling

In 2D tool simulations the inverse profile of the deflection can be exported to CAD so you can build your dies to compensate for the deflection. For instance in the following forging sequence:

A tool simulation of the end of stroke showed that the die deflection was greatest at the center of the die.

The inverse of the die deflection was exported to cad and the forging with the new die showed much more even deflection that was well within the design tolerances.

Coupled simulations

QForm version 7 can perform coupled simulations that simulate the die and the tool together and show their influence on each other. QForm 7 can perform coupled mechanical as well as coupled thermal simulations. In the following example you can see the advantages of a coupled mechanical simulation.

This forging was run with and without a coupled mechanical simulation.

Non-coupled simulation Coupled simulation

You can see the difference in the flash. In coupled mechanical simulation, the die deflects during the forge stroke so that there is more volume for the workpiece to fill. Therefore the flash does not extend out as far in the coupled mechanical simulation.