Hi everybody,
I need to run a blast simulation in ABAQUS using CEL technique.
The model need a soil section, a mine (TNT) section, air and the vehicle under study.
I've imported a vehicle CAD model into the workspace, assigned the solid section to the vehicle and have generated the Eulerian part.
So using "Predefined Fields" how should I assign the remaining Eulerian space (excluding the vehicle) as air, or as a general question, how could I subtract any object from an Eulerian part so I could assign materials accordingly ?
Hello,
The CEL is an advanced technique in Abaqus. The way to define the material property for Eulerian part is different from the normal L part. You need to go the interaction section and use discrete field via volume friction control. The rest should be easy to follow.
Regards
Robert
Robert and Rahul, thanks for your quick reply.
Indeed, yes, I have tried to assign materials using volume fraction tool and discrete fields in "Predefined Fields". Here are the steps I take, which lead to the problems:
1. create an Eulerian part, and mesh it.
2. import the STEP CAD file of the vehicle as a deformable solid, and mesh it.
3. create deformable parts (for TNT placement and air filled space) for assigning the up coming TNT and air discrete fields.
4. introduce the materials (steel, TNT, air).
5. create sections accordingly.
7. create independent instances.
8. subtract the vehicle instance from the air instance so the air will not be defined into the vehicle.
9. create discrete filed in predefined fields and assign TNT and air accordingly.
10. no boundary conditions defined
11. apply gravity body load.
13. create normal and tangent (rough) interactions.
14. create steps,
15. create job and run the simulation.
Which ends up in this error:
"The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file."
ps. If I try to not to assign the discrete field for air, the error is gone. But the object will not move either.
ps. I really don't get the point iof defining a TNT material using JWL equations. because firstly, I don't know how defining a material alone would end up in a load. secondly, I use CONWEP for applying the blast load. seems like I misunderstand and confuse two approaches here.
This error normally designates to the inconsistency in the unit system
kindly check properly you have used a consistent unit system. specially for unit of density
Thanks Rahul.
I will report the corresponding result during the Weekend,
Yes, the material properties suffered from inconsistent unit definitions.
First in the section definition,must be add a row under Air(euler) and select the TNT mat.
so,in p redefine(load module) predefined in initial/mass assign, to row with Air and TNT,each row select number "1"(void=0).
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