Dear all,
I am working on create a zero thickness COH3D6 element in Abaqus. Part of the issue is to correct numbering the COH3D6 element. I tried one algorithm below to check the node numbering:
And the code I created based on this algorithm is below:
A1_A2 = Coor(A2,2:4) - Coor(A1,2:4); A1_A3 = Coor(A3,2:4) - Coor(A1,2:4); Bin_normal = cross(A1_A2, A1_A3); CACB = El_Cen_B - El_Cen_A; Bin_dot = dot(Bin_normal, CACB); if Bin_dot>0 NewCohEl=[A1 A2 A3 B1 B2 B3]; end if Bin_dot<0 NewCohEl=[A1 A3 A2 B1 B3 B2]; end
However, when I used these created COH3D6 elements to run the simulation, the Abaqus gave me an error below, and this error message applied to 30% of the COH3D6 elements I created.
"The thickness calculated from geometry is negative for element 267 instance instance-1. Check if node
numbering is correct. This message will be printed a maximum of 5 times.
THE THICKNESS CALCULATED FROM GEOMETRY IS EQUAL TO ZERO FOR ELEMENT 267 INSTANCE INSTANCE-1. THIS IS NOT ALLOWED IN Abaqus. A NON-ZERO THICKNESS VALUE SHOULD BE SPECIFIED IN THIS CASE. THIS MESSAGE WILL BE PRINTED A MAXIMUM OF 5 TIMES."
If somebody know the reason or could give me some hints regarding on this, it is much appreciated!
Thanks a lot for your time,
Bin