Recall that the smoothed position of a vertex node is only accepted if the
quality of its ball did not get worse. In analogy, the smoothed position of a
mnidnode will only be accepted if the quality of its shell does not get
worse. For the quality measure of a quadratic element the largest difference of the
Jacobian determinant at the integration points will be taken as
measure. Recall that the 10-node tetrahedral element has 4 integration
points. The quality of quadratic element is now defined as:
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(968) |
where if
and
if
. The second term in the above
equation takes precedence as soon as any Jacobian determinant in the element
is negative.