Simufact introduced the first version of its special module for ring-rolling simulation in 2008. This module made it easy for process engineers to set up the complex kinematics of a ring-rolling process, and then to perform a full 3D simulation in less CPU time than ever before. Simulations that used to take several weeks of CPU time now ran within 1-3 days. The new module was recognized as a breakthrough capability in simulation because, for the first time, it was possible to use simulation as a practical approach to reduce development costs and shorten time to market.

The program’s ring mesher accurately represents the shape with a minimal number of elements.
Ring subdivided into eight domains, to run in parallel on a computer with eight cores.
A schematic view of the RAW ring-rolling process.
An elastic mandrel in ring-rolling simulation.

One of the most important capabilities included in the initial version of the ring-rolling module is its so-called “ring mesher”. During a finite element simulation, the geometric shape of the ring is subdivided into small “elements,” and it is critical to do this in the most efficient manner possible. The ring mesher was developed to represent the ring most accurately with a minimal number of elements — which is necessary to reduce the required CPU times to complete a full 3D simulation.

To reduce the required CPU time even further, parallel processing is used. During the simulation, the ring is subdivided into multiple “domains’ and then each domain is simulated on a different CPU. Because the simulation of each domain is done simultaneously, or “in parallel,” the results will be available much sooner. Most of today’s desktop computer hardware employ quad-core, or even sixcore, CPUs. On a computer with two CPUs, each with four cores, it is possible to split the model into eight domains. Simufact.forming is a registered Intel Cluster Ready solution, guaranteeing adherence to the industry standard implementations for High-performance computing.

In order to earn industry acceptance it was critical for the ring-rolling module to be transparently integrated within the regular Simufact.forming environment. This is important because almost all manufacturing processes for a rolled ring consist of multiple steps.

The ring-rolling process typically starts by heating a round or square billet to the forging temperature. Then, this heated billet is upset and a center hole is punched. When the billet is round, these stages of the process can be simulated using the 2D capabilities of Simufact.forming. If the billet is square, these stages are simulated in 3D, but symmetry conditions can be taken into account.