i try to modeling of layered shell (composite) S8R connected with spring element at edge faces, however it’s not working and throw some error message. these problem does not occurs with non composite shell element.
*ERROR in changekon: element type unknown: element: 32 type: ESPRNGA1
while trying to recreate the issue → everything worked fine for that simple problem. so its not necessarily a general issue. i will look for other reasons, but the error warning is the same for me in my original modelling.
there seems to be no connection between the error and the spring being placed on the edge of the shell. i just tested it and for both cases(on the edge and on not on the edge) i get the same error.
the model you are mentioning is a composite(layered shell). i havent tested it yet for non composites. but i can confirm that the same error occurs when truss elements are used instead of spring elements.
what i have experienced so far is that if you use composite with one layer it will work. if you use composite with more than one layer it wont work. if you use a noncomposite it will not work. it doesnt make a lot of sense but thats what ive experienced so far.
futhermore in your whole shell modelling there has to be ONLY one layered composites. if you have one face which has multiple shell layers even if it is not connected to a spring, the error will occur.