7644x
003160
2019-09-26

Question

I get error message 30420 saying that the tolerance (epsilon) for the integration of a node into a line is too large. What can I do?


Answer:
The tolerance epsilon can be found in the FE mesh settings in the "General" section of the dialog box. It controls the behavior of the FE mesh generator when nodes are very close to lines. Image 03 shows the difference. If the tolerance is greater than the distance of a node to a line, this small local difference in the mesh generation is neglected. In the case shown, the mesh of the line is deflected towards the node. In this case, the line is no longer ideally straight. If the tolerance is smaller than the distance, a separate FE node is generated for the node.

The error message appears if the distance between two adjacent nodes is smaller than epsilon and they are connected by a line (see Image 03). In most cases, this is due to an inaccuracy in the modeling. Since the error message contains no information about the node numbers, you can use the "Identical Nodes" model check. The program searches for nodes whose distance meets the tolerance delta. Now, you can set the tolerance value to the value of epsilon. The nodes are then listed in the upper part of the dialog box.

As described below, the descriptions differ depending on the case. If there is an inaccuracy in the modeling, it can be adjusted. In other cases, it is possible to further reduce the tolerance of epsilon, of course.