Create Solid Mesh Internal Beams in Femap9 Mar, 2014 By: Alastair Robertson
Femap Tips and Tricks: Learn how to set up models that represent rod or beam elements inside solid 3D elements.
Editor's note: This tutorial courtesy of Siemens PLM.
Structures such as reinforced concrete (where steel rebar is encased in solid concrete) can be represented by 1D rod or beam elements for the rebar inside solid 3D tet-elements for the concrete. When setting up such a model you have to ensure that the mesh is contiguous and that the 1D elements connect with the 3D elements correctly.
For clarity, we’ll demonstrate how this may be set up in Femap using a simple model of a solid block that will represent the concrete; it contains three internal curves that will represent the rebar.
First, we need to create mesh points on the surfaces where the internal curves connect to ensure that the surface mesh will create nodes at the internal curve positions. Select Mesh > Mesh Control > Mesh Points on Surface… and pick the first surface to which the internal curves connect. Select Use Existing Points and click OK, then pick all of the curve end points on the selected surface and click OK. Now repeat for any other surfaces that connect with curve end points.
Now we can mesh the internal curves to create rod elements in this case, as they will adequately represent the tension/compression properties of the rebar. Select the Mesh Curve icon, and select all internal curves. Enter an appropriate property type and click OK.
The next step is to mesh the bounding surfaces. Select the Tet Mesh Solid icon, pick all the bounding surfaces, and click OK to close the Entity Selection dialog. In the Automesh Solids dialog, activate the Surface Mesh Only checkbox. Ensure that an appropriate property is entered and click OK.
To verify that the meshing points have been picked up correctly, select the Wireframe icon in the pull-down menu of the View Style icon in the View toolbar.
Click the Undo icon to revert to the previous view style.