Evaluating Nodal Stresses in LS-DYNA — Lesson 3

How do you retrieve nodal stresses from LS-DYNA calculations?

By default, LS-DYNA stresses are element mean stresses located at the element center. If nodal stresses are required in output, for example, comparing the LS-DYNA solution with the Ansys Mechanical software’s Static Structural results, you must extrapolate the element stresses to nodes.

The attached archived project shows an example of retrieving the nodal stresses. In the example, the von Mises stress at the selected node in Mechanical software’s Static Structural system, which always output the stress components at nodes, is 37.954 MPa. Refer to the attachments to access the solution.

The LS-DYNA results show the stress at the same node is 36.972 MPa in Mechanical GUI. If the keyword snippet is used to ask for the output of nodal stress and specify the element ID of the node, LS-DYNA software will create the output file eloutdet, which can be either opened in LS-PrePost or a text editor. The final stress at the selected node is 37.046 MPa, which is in better agreement with Mechanical results.

You can access the relevant file here – Download File