Gmsh is an open source 3D finite element mesh generator with a built-in CAD engine and post-processor. Its design goal is to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization capabilities. Gmsh is built around four modules: geometry, mesh, solver and post-processing.

Gmsh allows a particularly good link between the mesh generator and the Lagamine solver.

(gtl for Gmsh To Lagamine)

This file contains all the specific informations that are in the '.lag' file, it corresponds to point:

- 1.Title

- 2.Control data of the program

- 3.Nodes ⇒ Add nodes to the list of nodes (they have no condition or mesh), these are usefull for specific fondations that can't be created in Gmsh.

- 5.Degrees of freedom (DOF) renumbering

- ???? 6. Duplicata nodes ????

- ???? 8. ID Matrix ????

- ???? 9-bis. Incremental forming ????

- 15.Constitutive laws

- 16.Fondations and tools

- 17.Elements → This section is a bit particular compare to the .lag file, before defining any type of elements, the word “ELEM” has to be read. Moreover, each element group has to be determined with 2 digits next to their name, which correspond to the name of the physical group used in the '.geo'/'.msh' file.

It represents the geometry of the simulation, from this file it is possible to get the '.msh' file.

In Gmsh, it is possible to create entities that are called “Physical group”, each Physical group has a tag and a name. the first one is automatically given by Gmsh. The name will follow a convention to give the rest of the information that is not contained in '.gtl' file, to compute the '.lag' file.

This convention is based on the Docuwiki numerotation:

They are automatically extracted from the '.msh' file.

For example, to apply gravity along axis x, with a value of 9.81. The name of the Physical group has to be “GRAVI019.81” or “GRAVI019.81000000”.

For more complex problem, it is possible to fix other DOF, it is possible to give a number between 01 and 09 which correspond to the DOF that has to be fixed.

Not yet developped.

Not yet developped.

Not yet developped.

Not yet developped.

Not yet developped.

Not yet developped

BLZ3D is the only possibility for the moment.

For example, if a simulation needs two different type of BLZ3D. Two physical groups have to be determined in GMSH with “BLZ3D01” and “BLZ3D54” as name.

For BLZ3D, it is possible to use initial stresses. To define them, the '.geo' file needs a physical group

For example, to get a group of BLZ3D with 2 initial stresses in direction 02 and 05, we need to define two physical group “BLZ3DIS02250” and “BLZ3DIS050000000010”

The interface calculate the variable that are used to allocate tables in Lagamine. Which are NUMNP, NELTP, MELEM, NDISP, NFOUN, NSEGT, IPILO, NLAW; NMASC, NDAMC, NVEL0, NACC0.

To keep the same format as in the '.lag' file, these numbers have to be filled but their value will be corrected.