My euphoria on the topic of principal stresses was premature. I was so pleased to find that the eigenvalue method avoided all the EDividebyZero exceptions in certain test files that I didn't notice it raised a number of EAccessViolation exceptions in entirely different files. The solution was to put the two methods, eigenvalues and poly roots, in series, for version 1.3 of Vtkpost. My latest tests indicate that no nodes in the entire test file group escape from this treatment, (excepting files that fail conversion anyway).
Right after release of version 1.0 I learned it was
tied to a .dll I was not aware of. Cutting this tie
resulted in version 1.1. Shortly afterward I found I was
able to do something I had wanted to do for some time:
calculate principal stresses directly through eigenvalues
rather than solve the cubic polynomial. This new
method resulted in version 1.2. The eigenvalue route does not
offer additional accuracy, but it does make it possible
to calculate principal stresses for nodes which were
not tractable before. For a concise explanation
of the math dealing with principal stresses, see:
So now I feel that Vtkpost is in better shape, and, surprisingly,
is even a bit smaller!
After a test download, I judge the Vtkpost package to be viable.
If you are not familiar with CalculiX, it is the most user-friendly, well-documented, and versatile free finite element analysis application that I know of. The main link for CalculiX is: http://www.calculix.de/
You owe it to yourself to check it out.
CalculiX has its own post-processor, usually referred to as CGX, which in several important respects is better than ParaView. But granting that CGX is indispensable to CalculiX, there are still several nice things about ParaView that are worth having available. ParaView has excellent visual responsiveness, the color mapping is appealing, the viewing space is large, a plethora of customizable features are included, and it offers data analysis tools. ParaView is free software, with ports to several platforms.... read more