Check elements: Check angles, orientation, etc.
Some checks on the finite element structure are done. The IDs of all the elements, which haven’t passed these tests, are saved as a new element selection set, these elements can also be graphically marked. This set can be modified later, for example by applying the command Type2Type for converting 4-node elements with very large or very small vertex angles into two 3-node elements.
The dialog remains active until pressing „Cancel“ closes it. After specifying the parameters the check is started using „Apply“.
Following dialog shows the available options:
Vertex angle (min-max): Vertex angles of all selected elements are checked against the smallest and the largest permitted value, that have to be given in the input field.
Distortion (max): Distortion of 4-node elements is checked by calculating the angle between the normals in node 1 and 3 of the element. Maximum permitted value has to be given.
Orientation (vx,vy,vz,cs): The scalar product for the normal of the element and the given vector is calculated and checked for a positive sign. For all elements with negative results it’s asked for turning the orientation in the opposite direction by reordering the vertices. Optional parameter cs can be the ID of a local coordinate system. In this case the orientation is calculated within this system.
Edge length < dmax: All elements are checked against an edge length lower than the given value.
Edge length > dmax: All elements are checked against an edge length greater than the given value.
dmax/dmin > fact: The ratio of the largest and the smallest edge length is calculated and checked against the given value.
Double defined elements: All elements are checked against each other whether there are elements with identical vertices. For this check it’s distinguished between equal (Option “Plus”) or opposite (Option “Minus”) direction. In case double defined elements are found, the IDs of these elements are saved under Set1 and Set2. By selecting one of these sets afterwards the related elements can be removed with the command Delete. Please note that only surface elements are checked.
Box product: Box product (triple scalar product) for solid elements is checked at all corners for equal sign. The sign is taken from the first solid. If option „Correct“ is marked the orientation of elements with a negative box product is automatically corrected.
Input field: Within this input field the numerical values for the above selected check must be given, angles are to be given in degrees.
Only selected elements are checked.
Select the set (1 to 3) into which the IDs of the elements, which don’t pass the checks, should be stored
With this option set all elements that do not pass the check are shown graphically by using a distinct color.
This refreshes the graphics