“Remesh”, the new function in COPRA^® FEA RF

In recent years it has become apparent that the use of Finite Element Simulations will be more and more important in the roll forming industry. Due to growing popularity of light weight construction, the sheet thickness is constantly being reduced, to compensate the loss in stability; more and higher strength materials are being used. More and more profiles are also being rolled with pre-punched material, where the quality of the holes in the final section in terms of correct position and shape are also an important issue.

For all cases, only little experience and trial and error method are available within the roll forming industry. Therefore, the only way to avoid expensive and time wasting experiments is to virtually simulate the process with FEA.

This is the reason why data M Sheet Metal Solutions GmbH has on the one hand focused upon making the roll design faster, and on the other to take away the time wasting modification of the FEA mesh when using pre-punched material, with COPRA^® FEA RF. The target being to significantly reduce the time required for preparing an FEA simulation.

Beside the possibility to “automatically mesh pre-punched material”, a new function was added to COPRA^® FEA RF. The “remesh-functionality” has been listed on the data M Sheet Metal Solutions' wish list of development for a long time now. A technical solution has been realised by now in which the Mesh can be redefined as needed during the simulation.

The current results are interpreted and assigned to the new mesh. The remesh can be performed both locally and globally. The elements must not be refined equally in all directions, but can also be refined in cross sectional direction only, for example when a new bend will be formed in the following station. With this opportunity, the number of elements corresponds with the present bends that are in the cross section and must not be allocated from the beginning of the simulation.

Besides the significant gain in simulation time (about 30-40% for typical roll forming applications) also a clear improve in quality can be faced: The position of existing element-refinements to describe specific bends will be adapted according to the truly occurring deformations (i.e. caused by necking). An optimal description of the bends can be guaranteed through the complete simulation of all roll forming stations with a minimal number of elements and without intervention of the user.

Fig. 2 and 3: Remesh of the simulated tube: refinement of elements in one direction at specific positions in the cross section. Results will be mapped to the new mesh.

        
Fig. 4 and 5: Further forming: round to shaped profile with adequate mesh.

Of course data M Sheet Metal Solutions GmbH will also demonstrate at the BIEMH 2010 exhibition the new features of the latest and very successful roll form software called “COPRA^® RF”.