Building a model
Elements
The element types you can add, with their arguments in 2D and 3D.
Elements are in the Elements group. Click an element in the viewport or its row to edit it. The form changes with the model dimension.
| Element | Nodes | Main arguments | Model |
|---|---|---|---|
Truss | 2 | area, material, optional -rho | 2D, 3D |
elasticBeamColumn | 2 | 2D: A, E, Iz, transformation. 3D: A, E, G, J, Iy, Iz, transformation. Optional -mass | 2D, 3D |
dispBeamColumn | 2 | transformation, beam integration, optional -mass (uses a fiber section) | 2D, 3D |
ShellMITC4 | 4 | section | 3D |
ShellDKGT | 3 | section | 3D |
zeroLengthSection | 2 | section, optional -orient | 2D (skipped with a warning in 3D) |
Other OpenSees element names exist in the generated schemas but are not available in the element form.
Shells
Shells need a 3D model and an ElasticMembranePlateSection. List the nodes counter-clockwise; the normal follows the right-hand rule. Loads on shells can be nodal, self-weight or pressure. See Load patterns.
Fiber beams
In 3D a dispBeamColumn needs torsional stiffness (-GJ) on its fiber section and a Linear transformation.