3. B modeling

In this modeling, the crack is not meshed, and the mesh is chosen so that the crack bottom coincides with a node in the mesh.

3.1. Characteristics of the mesh

The structure is modelled by a regular mesh composed of \(6\mathrm{\times }6\mathrm{\times }6\) HEXA8, respectively along the \(x,y,z\) [Figure 3.1-3.1-a] axes. The crack bottom is therefore located at the center of the elements containing the crack bottom. In addition, the crack coincides with the edges of the elements.

Figure 3.1‑ 3.1-a : mesh such that the background coincides with a node

3.2. Tested features

We test the application of Dirichlet conditions via the AFFE_CHAR_MECA command on enriched nodes (here, nodes enriched doubly: by the Heaviside function and by the asymptotic functions). This imposition is done as for the nodes using the keywords DDL_IMPO or FACE_IMPO.

3.3. Tested sizes and results

We test the values of the movements of the nodes on which the conditions have been applied.

As the crack passes through the nodes of the mesh, the conditions were applied to both lips of the crack.

So there is no need to filter the nodes here. All new nodes are tested.

To test all the nodes in the group at once, we test the min and max values.