I am working for the FE model of cracked pipes. I use Hypermesh to mesh the model, but the element can not be set to the C3D20R type. I donnot kwon why it is. So I can use the C3D15. Then I can th following error message:
***NOTE: THE COORDINATES OF NODES WITHIN THE SAME CLUSTER ARE NOT IDENTICAL.  THIS IS THE CASE FOR NODES 22 1224

***ERROR: TRIANGLES, TETRAHEDRA, AND WEDGES MAY NOT BE USED IN A CONTOUR INTEGRAL REGION. ELEMENT 960 IS WITHIN A CONTOUR REGION

 ***WARNING: NO VALID ELEMENTS FOUND IN CONTOUR INTEGRAL REGION
 
 What's wrong?
 
 Thanks a lots for your time.