Chris Quan
Ansys Employee

Are you using Autodyn Component system? If yes, you need to check if the solid elements are connected with the beam elements in your model for both simulations.

In AUTODYN GUI you can JOIN two parts together from the left navigation bar by click on JOINS -> Join, select parts from dialog window, and then click APPLY to join these parts together.

JOIN acts like bonded contacts in ANSYS Workbench Mechanical GUI. Please be aware that JOIN logic in Autodyn GUI is different between structured (IJK-based) mesh and unstructured mesh. 

For IJK-based mesh, you need to make sure all nodes on the joining interface from each part match each other. Otherwise, parts won’t be joined together. In your model, the beam nodes from line bodies have to match the nodes of Lagrange elements from solid body. You can plot grid of your joined parts to make sure nodes on the interface match each other.  
For unstructured mesh, nodes are not necessarily matching each other at the joining interfaces. You can create Bonded Face Connections to join surfaces together. You can create new groups of faces via GROUPS -> NEW -> POLYGON ADD for bonded face connections. In your model, you need to make sure the line bodies are alingned with the edges of Lagrange elements but their nodes are not necessarily matching each other.
Finally, you can plot the Joined Nodes or Joined Parts using Joins from the left navagation bar and then check the box of "Plot joined nodes" or "Plot joined parts" to confirm the properly setup of Joins.