Rigid element - young's Modulus - density

[matthiaslaga]

Hello,

I'm a new member of Abaqus and I want to model a solid rigid body part (revolution) (steel: E-modulus = 210*10^9MPa and v=0.2) and deformable part (revolution) (sand). (See attachment bucket with surrounding soil).

http://files.engineering.com/getfile.aspx?folder=34d6966a-da6a-49e3-b6a3-1fb091f22704&file=rigid.jpg

However, I is not possible to give a rigid part section assignments? I already tried to give the rigid part a nonstructural mass - total mass but then I get the error:
"MASS PROPORTIONAL DISTRIBUTION OF NONSTRUCTURAL MASS IS NOT ALLOWED WITH ELSET ASSEMBLY_BUCKET-1_SET-2 AS NONE OF THE ELEMENTS HAVE A STRUCTURAL MASS. PLEASE DEFINE A DENSITY TO GENERATE STRUCTURAL MASS OR, IN ABAQUS/Explicit ONLY, USE VOLUME PROPORTIONAL DISTRIBUTION."
How can you define a density to the rigid part if it's not possible to use section assigments?

many thanks in advance
Matthias

 

[Mustaine3]

What kind of rigid are you using? Usually a deformable part (regular elements) is made rigid. On such a part you can apply a solid or shell section with reference to a material.

 

[DrBwts]

Rigid parts dont need section assignments.

If you want a rigid body on Abaqus CAE you have to select that option when creating the geometry for the part.

The mass is taken care of when you assign the parts inertial properties.

 

[matthiaslaga]

Is it also possible to make a deformable part (+ give my part section assignments) and than with constraint - rigid body - body elements make my part Rigid after pointing a Reference Point (RF)?
Let me know
Matthias

 

[DrBwts]

I am finding your question confusing.

I dont think its possible to do what you are asking. If you want a rigid body then you have to construct the geometry as rigid to start with.

If the part is rigid then assigning something like Young's modulus has no meaning as the stress state of the part is not calculated for rigid bodies.

Does that make sense?

 

[Mustaine3]

It is possible and very common to have the part type Deformable and apply a rigid body constraint in the interaction module. So you have a regular section and material assignment on that part, which can be used to calculate the mass and inertia later.

 

[DrBwts]

Thanks Mustaine3 I had no idea you could do that. Are the parts then just treated as rigid in the analysis?

If so this could solve a nagging problem I've been thinking about.

 

[Mustaine3]

They behave like rigid elements (can't deform, have no element results, refer to a reference node, ...).