how a normal human being can understand this formulas. i am a civil engineer working in India. prepomax is a really good software to learn, while learning contacts topic I saw this formulas. i worked 20 years in civil engineering bridge design, i can understand normal things like force/area, Moment of inertia, direct stress strain , but understanding these formula requires something different mental capacity i guess.
What is the source of this screenshot ? Are you looking for some specific theoretical aspects such as contact formulations ? I can recommend you the most recognised literature in this area.
Since PrePoMax is a pre- and postprocessor, its manual doesn’t cover theory. This is on the CalculiX side and you can find some details in its manual: https://www.dhondt.de/ccx_2.23.pdf
But the most comprehensive theoretical guide for CalculiX is the book written by Guido Dhondt (CalculiX developer) titled “The Finite Element Method for Three-Dimensional Thermomechanical Applications”.
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This is actually the ccx manual.
@OP, we as simulation engineers are indeed happy of every kind of documentation of the ccx source code (as shown by this page). This gives us the ability to understand, what the solver is going to achieve. Nevertheless, this is a down-side for the casual user. Tutorials (e.g. Youtube) / Examples / Workshops on the other hand might be more convenient for those kind of users.
Best regards,
Patrick
Theory guides (such as section 6 of the ccx manual, also including a lot of practical information, or Guido’s book) are needed, even though they sometimes use rather non-intuitive notation. A good example is Theory Guide of Abaqus. I wouldn’t recommend it if someone just wants to learn about basics of FEM, but it can still be very helpful when there’s a need to dig deeper into the solver procedures or write some subroutines.
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it’s node to face contact related document, each parameter in formula needs to clearly be showed by graphics and definition. Nonlinear spring element required for numerical stability when infinite rigid is used. Complex form as shown in documentation raised due to non-orthogonality i.e arbitrary plane and iteration during movement to find stable position meaning convergences. More math geometry behind this formulation instead of engineering. Contact is basically simple like dead element of soil foundation spring working in compression only, another example but opposite is tension only in brace of building or bridge.
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The standard literature when it comes to contact mechanics in FEA is the book by P. Wriggers (Computational Contact Mechanics) who developed the traditional master-slave algorithm. Of course, there are many other publications on this topic.
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This isn’t a program for the average engineer. It has too many advanced analysis options and is very sensitive to modeling errors.
Same as Abaqus, apart from some extra limitations you have to be aware of in CalculiX. Designers can easily run simple linear analyses as preliminary checks, but going any deeper requires much more effort. Most importantly, the old GIGO rule always applies.
or did it expect the document to be merged with PrePoMax manual? i don’t think so. Theoretical background is in solver domain not the interfaces, even large commercial ones made it separation. Provide basic information in manual and menu seems to be enough, added a bit more detail in the future can helpful indeed but not to compete with official solver or mesher manual.
specific problem related to solver recommended post in official CalculiX forums responding to the authors and team. PrePoMax looks focusing on user interface, extending features not available in solver also.
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Exactly, I was going to add that too - it would be best to discuss the contents of the ccx manual and other solver/theory aspects on the CalculiX forum. Guido (ccx dev) still apears there from time to time.
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