{"id":302982,"date":"2023-08-24T01:34:29","date_gmt":"2023-08-24T01:34:29","guid":{"rendered":"\/forum\/forums\/topic\/undetectable-error-mostly-combat-instabilities\/"},"modified":"2023-08-24T01:34:29","modified_gmt":"2023-08-24T01:34:29","slug":"undetectable-error-mostly-combat-instabilities","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/undetectable-error-mostly-combat-instabilities\/","title":{"rendered":"Undetectable Error – mostly combat instabilities"},"content":{"rendered":"

Hello,<\/p>\n

I’m trying to model a full RC bridge using LS-DYNA. In this model, one of the pier columns is subjected to the impact of a Single Unit Truck. After that, an explosion charge is detonated. <\/p>\n

I’m using the ALE approach to model the Air, Soil, and Explosive, and all structural elements are modeled using solid elements (except steel reinforcement which is modeled using beam elements). Unfortunately, I’m encountering some issues that I couldn’t resolve over the last two weeks. <\/p>\n

All Lagrangian solid elements are deleted at the very beginning (first two to three time steps), and I get error termination even without an explicit error message. I’ve tried several things to resolve the problem, as summarized below, but nothing changes:
1- reducing time step scaling factor (TSSF) and (DT2MS).
2- Changing solid element type to constant stress (Elform = 1).
3- Using Types 4 and 5 hourglass controls with a coefficient ranging between 0.01 and 0.05.
4- Reconstructing the mesh.
5- Using IMASCL = 2 in the Control ALE option.<\/p>\n

Any recommendations?<\/p>\n","protected":false},"template":"","class_list":["post-302982","topic","type-topic","status-closed","hentry","topic-tag-an-unknown-error-occured-1","topic-tag-ansys-ls-dyna-1","topic-tag-instability","topic-tag-negative-volume-detected","topic-tag-warnings"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t