Surface Contact Extension
Surface Contact Extension
(OP)
Hello,
I'm having a bit of difficulty creating surface constraints in ABAQUS. Currently, I have an imported mesh of a knee generated from ScanIP. I set up contacts in ScanIP, and so when I import it, ABAQUS recognizes the contact nodes from the original mesh. However, I'll be putting a load at the top of the knee, and my parts will slide past these predefined contact points. Thus, I want to extend my contact zones to cover entire surfaces (i.e. medial femoral cartilage --> medial meniscus).
I tried to do this by going to tools -> surface -> manager -> edit
I edited each contact area by selecting the entire surface of my parts using the "select by angle" mechanism. However, when I run the model, it's pretty evident I've made a mistake because my femur is not recognizing the contact underneath it and is sliding all the way through my tibia. I'm getting warning messages saying that node constraints are being removed.
If anyone has any advice or insight into this, I would be much appreciative!
Lance
I'm having a bit of difficulty creating surface constraints in ABAQUS. Currently, I have an imported mesh of a knee generated from ScanIP. I set up contacts in ScanIP, and so when I import it, ABAQUS recognizes the contact nodes from the original mesh. However, I'll be putting a load at the top of the knee, and my parts will slide past these predefined contact points. Thus, I want to extend my contact zones to cover entire surfaces (i.e. medial femoral cartilage --> medial meniscus).
I tried to do this by going to tools -> surface -> manager -> edit
I edited each contact area by selecting the entire surface of my parts using the "select by angle" mechanism. However, when I run the model, it's pretty evident I've made a mistake because my femur is not recognizing the contact underneath it and is sliding all the way through my tibia. I'm getting warning messages saying that node constraints are being removed.
If anyone has any advice or insight into this, I would be much appreciative!
Lance





RE: Surface Contact Extension
RE: Surface Contact Extension
RE: Surface Contact Extension
Are you new to this forum? If so, please read these FAQ:
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Surface Contact Extension
RE: Surface Contact Extension
You should avoid selecting regions (for contact surface assignments) that are not expected to come in to contact. Otherwise, the contact solver is forced to keep track of normals on surfaces which will never come in to contact; it is an unnecessary expense. In small models, this is nothing to bother about but, in large or complicated models, one has to pay attention to the details. When it comes to biomechanics, it doesn't take too long before the models become complicated.
Are you new to this forum? If so, please read these FAQ:
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Surface Contact Extension
The problem is, as far as I'm aware of, everything in my model (that I'm concerned with) is disjointed, so there shouldn't be any part in my model that's sharing a node. My cartilage is completely disjointed from my meniscus, so when I select each surface as a contact zone, there shouldn't be any nodes that are "common between 2 contact pairs".
I do not get this error when I keep the original contacts as is from the original imported mesh. Thus, the problem specifically is when I attempt to extend these zones.