Finite Element Mesh
The F.E.M. (Finite Element Mesh) is the basic core of any forging simulation program. QForm uses high order quadratic elements that are completely self-generated by the program. You don't need to know a thing about F.E.M. to ensure that QForm will give you the most accurate results possible. The program puts fine mesh in areas of greater detail and larger mesh in areas of less detail providing the ideal mesh for accurate results and fast speed of simulation. Look at the difference between a linear mesh and a quadratic mesh below.
Five nodes along a curved surface,
Linear vs. Quadratic F.E.M. mesh
LINEAR F.E.M. MESH
Notice the error of approximating a curve with a linear mesh.
QUADRATIC F.E.M. MESH
Notice how the curve in QForm is accurately approximated with quadratic
mesh using the same number of nodes along the curve.
QForm was the first software to use quadratic finite element approximation to solve 3D problems. Quadratic elements give a considerable increase in the accuracy of solution, as well as a reduction in the loss of volume. Quadratic F.E.M. allow for more frequent remeshing, without ‘shouldering’ the surface at tight curves, which is characteristic of linear elements.
In addition to the Quadratic mesh, QForm uses a self generating NON-UNIFORM mesh that uses fewer elements in areas where less is happening and more elements where detail is needed, This gives QForm great speed as well as great accuracy.
You can see that the combination of accurate high quality step geometry input and quadratic non-uniform mesh gives the optimum mesh for the geometry. The non-uniform tetrahedral mesh is very detailed in the areas of small radius and quite large in the areas where little deformation is taking place. This combination ensures an accurate simulation while achieving maximum speed of simulation.
For extreme accuracy, QForm can have up to three concurrent meshes with separate meshes for material flow, temperature, and strain.