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ANSYS Mechanical APDL Error regarding COMBIN39 element

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Old   May 2, 2019, 07:29
Default ANSYS Mechanical APDL Error regarding COMBIN39 element
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Florian Zapf
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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
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File Type: txt Reduced_model.txt (2.5 KB, 20 views)
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Old   July 28, 2019, 16:47
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Gwenael H.
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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
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File Type: txt Reduced_model_Corrected.txt (2.5 KB, 22 views)
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ansys 19.2, combin39, mechanical apdl, real constants

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