Knee Joint Abaqus.
Knee Joint Abaqus.
(OP)
Hi,
I am Aravind working with Abaqus for last few months. I am working on developing a knee implant. I am trying to do FEA analysis with ABAQUS. I am using TIE feature with femur and tibia and implant plates as well. I get the following errors.
The volume of 102 elements is zero, small, or negative. Check
coordinates or node numbering, or modify the mesh seed. In the case
of a tetrahedron this error may indicate that all nodes are located
very nearly in a plane. The elements have been identified in element
set ErrElemVolSmallNegZero.
NODE 26 INSTANCE TIBIAPLATE1-1 IS COMMON BETWEEN THE TIED PAIR
(ASSEMBLY_SCREW, ASSEMBLY_TPLATE2). NO CONSTRAINT IS FORMED FOR
THIS NODE.
***WARNING: 1169 nodes are common between the tied pair. no constraint is
formed for these nodes. The nodes have been identified in node set
WarnNodeCommonTiedPair.
And how to calculate the tolerance from Master to slave?
It would be of great help if you can help me with this, as I am trying for almost a month.
Thanks in advance
I am Aravind working with Abaqus for last few months. I am working on developing a knee implant. I am trying to do FEA analysis with ABAQUS. I am using TIE feature with femur and tibia and implant plates as well. I get the following errors.
The volume of 102 elements is zero, small, or negative. Check
coordinates or node numbering, or modify the mesh seed. In the case
of a tetrahedron this error may indicate that all nodes are located
very nearly in a plane. The elements have been identified in element
set ErrElemVolSmallNegZero.
NODE 26 INSTANCE TIBIAPLATE1-1 IS COMMON BETWEEN THE TIED PAIR
(ASSEMBLY_SCREW, ASSEMBLY_TPLATE2). NO CONSTRAINT IS FORMED FOR
THIS NODE.
***WARNING: 1169 nodes are common between the tied pair. no constraint is
formed for these nodes. The nodes have been identified in node set
WarnNodeCommonTiedPair.
And how to calculate the tolerance from Master to slave?
It would be of great help if you can help me with this, as I am trying for almost a month.
Thanks in advance





RE: Knee Joint Abaqus.
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: Knee Joint Abaqus.
Usually when I see this error it is because the geometry has small slivers. This is especially true if the geometry is from scan data or STLs. Without seeing the model it is difficult to suggest how to fix this though. I hope this helps.
Rob
Rob Stupplebeen
www.optimaldevice.com
RE: Knee Joint Abaqus.
Initially I had a very fine mesh and since I am trying to see the working functionality I have a very course mesh.
Thank you for your support and gesture. Its been a nice learning curve from this forum.
Cheers
Aravind
Link to image
http://files.engineering.com/getfile.aspx?folder=4...
RE: Knee Joint Abaqus.
Do you want to allow contact (i.e., interaction) between two surfaces or do you want to constrain the movement of a surface with respect to another surface?
By the way, if you use the Query tool to figure out the distance between nodes, then a more reasonable number for the tolerance should pop into your mind.
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: Knee Joint Abaqus.
RE: Knee Joint Abaqus.
Try using Mesh>Verify to find the bad elements.
Then Tools>Virtual Topology>Automatic Create. Virtual topology does slightly modify the base geometry typically to combine faces or edges together.
I hope this helps.
Rob Stupplebeen
www.optimaldevice.com
RE: Knee Joint Abaqus.
RE: Knee Joint Abaqus.
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