InStep - Help

Extract Surface

CAD mesh formats (from STL, OBJ, ...) have a different structure from FE mesh formats (NAS, GEO, OUT, ...). In order to get a CAD compatible mesh from a FE type source, it is necessary to find and extract surface information from the volume/FE mesh. This tool will find any surfaces of the FE mesh and convert them into a CAD suitable format, then load the resultant data as a new CAD data file, making sure that no issues are present in the data.

CAD to Surface Mesh

Similar to the conversion of CAD to FE mesh, the reverse is possible too where a FE mesh is to be constructed from a CAD type mesh. Though the CAD mesh does not contain the necessary information to generate a solid FE mesh, it can be used to generate a planar/shell mesh that can then either be used for structural simulations or inflated to form a 2D mesh thereby allowing CAD packages (where the STL facets are defined explicitly) to act as a low cost mesher.

Mesh Information

This tool provides basic information about the FE mesh loaded such as the types of elements present (does not include 1D elements), bounding box and basic statistics.

Add Surface to Volume Mesh

Some applications require that a surface (planar/shell) mesh accompanies the volume mesh. This tool generates the matching surface mesh and adds the elements to the global data.

Reorder Mesh

Some applications generate node and element IDs that do not start at 1. Other applications require that element IDs start at 1. This tool re-orders the vertex IDs and element IDs.

Inflate Surface Mesh

In some circumstances it can become necessary or convenient to use a surface mesh (or CAD surface) as the source defining the volumetric mesh. This tool allows surface elements (TRI, QUAD) from being thickened into their corresponding prismatic shapes (PENTA, HEXA). The tool allows definition of the number of elements and the total thickness. If the surface mesh is not flat but has curvature to it, the tool can still succeed, provided that the angle between neighboring elements allows the thickening by a vector that is the average of the node surrounding surface normals. If this is not the case, the tool will succeed nevertheless, but the resultant mesh will not be useful.

Delete Surface Mesh

Sometimes the imported mesh consists of both surface as well as volumetric elements. This tool deletes the surface mesh.

Delete Volume Mesh

For cases where the volume mesh is not required, this tool deletes all the volumetric elements.

Delete Unused Nodes

Depending on the source of the mesh, nodes may be present that are not used by any element. This tool deletes unused nodes from the set.

Rotate Mesh

Allows rotation of the volumetric mesh around a point in 3D and three angles which define the rotation around the X, Y, Z axis, applied in that order.

Translate Mesh

Translates a volumetric mesh by a given vector

Scale Mesh

Scales the volumetric mesh by a set of three values defining the X, Y and Z components. Uses a point in 3D to define the center of the scaling. By default the center is the center of the mesh.