Plugin Crack: Connecting Negative and Positive Part of One Physical Group
Hi everyone,
I'm using the Plugin Crack to duplicate degrees of freedom of physical regions. I've realized that the plugin does not work as one might expect when the plugin would need to connect (possibly newly created) nodes of one single physical region. This happens, for example, when one tries to use the plugin to copy the degrees of freedom of spiral turns as shown in the picture below and when no mesh nodes are used in between two turns of the spiral. In this case, for each pair of turns, the nodes of the inner turn would need to be connected directly to the outer turn.
I've attached a MWE consisting of 3 rectangles including GetDP code to solve a 2D Laplace problem on a structured quadrangular mesh. The crack plugin could be e.g. used to disconnect the middle rectangle from the other two completely (using OpenBoundaryPhysicalGroup). When there is no inner node in the middle rectangle, the latter is not completely disconnected as expected but the solution is continuous to the right rectangle. For one or more inner nodes, the middle rectangle is disconnected from both left and right as expected.
I don't know how complicated it would be for the plugin to also handle these cases as expected (or even if what I describe is the expected behavior). However, there is a workaround for anyone running into the same problem, you can simply separate the physical region that is to be duplicated into multiple physical regions. Then, you can use the Crack plugin iteratively on these sub-parts to copy the DoF (seems to work so far).
Many thanks!