Mesh Control Parameters
The section called Mesh Controls is for the mesh generated for semirigid diaphragms (note that any change in this section also affects the mesh generated for walls).
| Setting | Description |
|---|---|
| Max. Distance between Nodes on Mesh Line | it allows the user define the maximum distance between nodes on wall edges and nodes on semirigid diaphragm edges. The program may generate additional nodes closer than user entered value, but it is never allowed to be larger than that value. The user can generate coarse or fine mesh by setting Max. Distance between Nodes on Mesh Line. Usually, a coarse mesh gives conservative results since the walls and diaphragms are stiffer. A finer mesh leads to more flexible walls and diaphragms, which leads better results but it may significantly increase analysis time. The following figure demonstrates an example, which shows how this parameter affects generated mesh density: (a) shows a mesh generated with 16 feet whereas it is 2 feet in (b). |
| Merge Node Tolerance | Once meshing process for walls and semirigid diaphragms is completed, the program generates a finite element model for analysis, which is basically composed of nodes and elements (columns, beams, braces and shells in walls and meshed diaphragms). During this process, it is possible that several nodes are very close. To have a good (and valid) analytical model, these nodes are merged to a single node and elements connected to this node are adjusted accordingly. The Merge Node Tolerance is used in such a way that if distance between any 2 (or more) nodes are found to be smaller than the Merge Node Tolerance, then they are treated as a single node (i.e., these close nodes are merged together). |
| Geometry Tolerance | This is mostly used in geometry calculation as a threshold tolerance value. This should not be confused with a merge (close) node tolerance. Examples are as follows: it is used as a tolerance to check a node is on a line or to check a point is inside a polygon, etc… |
