Distance Visualization

In various fields of preprocessing, for example the visualization of potential flanges or the selective removal of initial penetrations the calculation and following visualization of the minimal node-element-distances of adjacent components plays an important role. To enable an interactive calculation of the minimal node-element-distances within a justifiable response-time every finite element mesh in the internal data-structure is divided using a bounding volume tree

Efficient Distance Calculation

Calculating the minimal node-element-distance between a certain node of the finite element mesh A and the elements of anotherfinite element mesh B the distance between the node and the mantlevolume H0 is calculated first. Only if this is smaller than the minimal distance currently stored at the node, the next layer of the bounding volume tree is regarded. Here there are either a division of the mantlevolume H0 into two smaller mantlevolumes H1 and H2 containing disjunct subsets of elements of H0, or some elements for which the minimal distance is determined successively.

In crashViewer various types of mantlevolumes have been implemted and tested. In doing so mainaxes-parallel boxes have been proved to be more efficient than spheres or object-oriented boxes.
The following picture shows the mainaxes-parallel bounding boxes of a finite element mesh at the first eight steps of division.

By the use of this approach for each node the bigger part of the elements can be excluded immediately and so the calculation is greatly accelerated, because the distance calculation from a node to the mantlevolume can be done faster than to a finite element. Also a big number of elements can be excluded from the distance calculation by a more distant mantlevolume.
The calculationprocedure can be further accelerated by initializing the current minimal distance at each node with a previously determined value that restricts the interessting range from the first.

Fields of Application

• Visualization of Potential Flanges


• Selective Removal of Initial Penetrations