Besides local refinement, global refinement, and several remeshing techniques, also macro regions can be defined which will automatically be divided in finite elements, and furthermore elements which are part of a region (geometry) can be deleted. This can be done at any time, so that assemblage and de-assemblage of parts of a structure in its life time are possible.

In the first example two crossing tunnels are generated in a brick. First the brick is generated. Then the elements belonging to the tunnel are removed. The nodes on the edge of the tunnels are replaced automatically to obtain the exact tunnel geometries. Then the tunnel is reinforced by a network of beams.

In the second example a mesh is generated to model a plate with some cylindrical particles of another material are included. You just need to specify that the particles are three circles, and TOCHNOG automatically adjusts the mesh for that.

Here is the first Inputfile. Here is the second Inputfile.