ANSYS Mechanical APDL Error regarding COMBIN39 element
 

Hello,


I have a problem using ANSYS 19.2 Mechanical APDL. I am trying to create a model using Beam 188 elements and non-linear Spring elements (COMBIN39). The spring elements require a specific force-deflection curve. These curves can be implemented using real constants. I have different real constants for the 1D COMBIN39 Springs. Some of these real constants cause the following error: "The last input displacement for element X must be positive."


I don't understand the error because all last input displacements of the real constants are positive. Also the error occurs only for R,3, in my script.



I have attached a text-file with the srcipt of a reduced version of my model.



I hope I have provided all information to help you understand my problem.



Thanking you in anticipation and with kind regards
MadBean

Hi Florian,



Your input and problem definition are correct. This is a tricky one if you didn't encounter it once before. The problem comes from the Real constant definition. You can only define up to 6 constants (see APDL reference manual > command reference > R) :


"Use RMORE command if more than six real constants per set are to be input."


This was causing your problem.



I've attached the corrected .txt version bellow.


Have fun ;)