Learning Forum

[Bandoro Yudhistira]

Hello,

I am currently experiencing an error in my underwater explosion (UNDEX) analysis using ANSYS Explicit Dynamics, and unfortunately, I have not been able to resolve this issue for almost three months.

Basically, I am trying to perform an underwater explosion analysis using the Coupled Eulerian-Lagrangian (CEL) approach in ANSYS Explicit Dynamics. My model consists of three main components: TNT, modeled using an Eulerian domain; Water, also modeled using an Eulerian domain; and the ship structure, including its internal structural components, modeled using the Lagrangian approach.

 

For the Eulerian domain, the Water and TNT geometries are combined using Share Topology so that they form a single connected Eulerian domain. On the other hand, the ship hull and its internal structural components are also combined using Share Topology to form the Lagrangian structural model. There is no Share Topology connection between the Eulerian domains (Water/TNT) and the Lagrangian ship structure.

However, when I attempt to solve the analysis, I consistently encounter the following error:

"ERROR: There are 37 shell parts that are joined or merged together in their plane. The Fully Auto Interaction method cannot handle this situation correctly; only shell parts that are joined or merged along their edges can automatically be thickened."

 

I have tried several approaches to resolve this issue, including repeatedly rebuilding and modifying the geometry, checking the connections between the shell bodies, and recreating the structural geometry. Unfortunately, the same error continues to appear during the solution process.

At this point, I am unsure whether the problem is related to the way the Lagrangian structural geometry is constructed, the Share Topology configuration, shell-body connections, or the interaction/contact settings between the Eulerian and Lagrangian domains.

I would greatly appreciate any advice or guidance regarding the possible cause of this error and the correct modeling approach to avoid it. If anyone has encountered a similar issue when performing a CEL-based UNDEX analysis in ANSYS Explicit Dynamics, I would be very grateful if you could share your experience or recommended workflow.

I have been working on this problem for almost three months and am starting to run out of possible approaches to troubleshoot it. Any suggestions regarding geometry preparation, shell connectivity, Share Topology, contact/interaction settings, or other relevant ANSYS Explicit Dynamics settings would be greatly appreciated.

[Sami jan]

It may be related to overlapping or merged shell parts in the geometry. Check the shell connectivity and Share Topology settings.