Element distortion check

Element distortion check

Ver: 0

DESCRIPTION

This menu allows to make the solver to use a warning or to stop when the quality of the finite element mesh degrades. This mesh quality is measured by one of the criteria defined in this menu. By default, none of those criteria is enabled. OPTIONS

-1
Accept the current set-up

1
No action if distortion limits exceeded

Make the solver to nothing special when the quality of finite element(s) goes beneath criteria.
That's the default.

2
Warning if distortion limits exceeded

Make the solver to print out a message when the quality of finite element(s) goes beneath criteria.

3
Stop if distortion limits exceeded

Make the solver to stop when the quality of finite element(s) goes beneath criteria.

4
Modification of the minimum interior angle

Sets the value of the minimum interior angle. Any element having a smaller interior angle triggers the action (warning, stop or nothing).
Interior angles are simply the angles measured between element edges that form a corner.

5
Modification of the maximum interior angle

Sets the value of the maximum interior angle. Any element having a greater interior angle triggers the action (warning, stop or nothing).

6
Modification of the maximum aspect ratio

Sets the maximum aspect ratio that is defined as follows :
        max. aspect rat. = max (Li/Lj), i,j=1,nb segments
        Li = length of edge i of the element
The max aspect ratio is always greater than or equal to 1. The aspect ratio should be limited to ten or less.

7
Modification of the maximum bend

Sets the maximum bend that is defined as follows :
       bend = 1 - n1.n2
If we cut a quadrilateral face of an element diagonally, we obtain two triangles. n1 is the normal to the first triangle, while n2 is the normal to the second triangle. A face or an element that is flat has a zero bend. Triangular faces and elements have zero bend by definition. Quadrilaterals have two bends defined by the two possible diagonal cut. The max bend is defined by the max value of the set of all bends in an element.

8
Modification of the maximum skew

Sets the maximum skew that is defined as follows :
       max. skew = max( [( abs(J) * S ) / ( integral( abs(J) ) dxi)] - 1 )
where J       is the Jacobian matrix for the transformation between the
                    actual coordinate system and the local coordinate system
abs(J) is the absolute value of J
S is the surface (volume) of a 2D(3D) element
xi is the local coordinate system
integral( abs(J) ) dxi is the integral over the element of the absolute value of J
For an optimal element, the skew is zero. As the element deviates from the optimal, the skew increases. A negative skew indicates a concave element.

SEE ALSO

remeshing (UM)

-1	Accept the current set-up
1	No action if distortion limits exceeded
	Make the solver to nothing special when the quality of finite element(s) goes beneath criteria. That's the default.
2	Warning if distortion limits exceeded
	Make the solver to print out a message when the quality of finite element(s) goes beneath criteria.
3	Stop if distortion limits exceeded
	Make the solver to stop when the quality of finite element(s) goes beneath criteria.
4	Modification of the minimum interior angle
	Sets the value of the minimum interior angle. Any element having a smaller interior angle triggers the action (warning, stop or nothing). Interior angles are simply the angles measured between element edges that form a corner.
5	Modification of the maximum interior angle
	Sets the value of the maximum interior angle. Any element having a greater interior angle triggers the action (warning, stop or nothing).
6	Modification of the maximum aspect ratio
	Sets the maximum aspect ratio that is defined as follows : max. aspect rat. = max (Li/Lj), i,j=1,nb segments Li = length of edge i of the element The max aspect ratio is always greater than or equal to 1. The aspect ratio should be limited to ten or less.
7	Modification of the maximum bend
	Sets the maximum bend that is defined as follows : bend = 1 - n1.n2 If we cut a quadrilateral face of an element diagonally, we obtain two triangles. n1 is the normal to the first triangle, while n2 is the normal to the second triangle. A face or an element that is flat has a zero bend. Triangular faces and elements have zero bend by definition. Quadrilaterals have two bends defined by the two possible diagonal cut. The max bend is defined by the max value of the set of all bends in an element.
8	Modification of the maximum skew
	Sets the maximum skew that is defined as follows : max. skew = max( [( abs(J) * S ) / ( integral( abs(J) ) dxi)] - 1 ) where J is the Jacobian matrix for the transformation between the actual coordinate system and the local coordinate system abs(J) is the absolute value of J S is the surface (volume) of a 2D(3D) element xi is the local coordinate system integral( abs(J) ) dxi is the integral over the element of the absolute value of J For an optimal element, the skew is zero. As the element deviates from the optimal, the skew increases. A negative skew indicates a concave element.