cohesive simulation problem 1

[CKJK]

Hello, I am trying to simulate two spheres cohesive process, I watched a tutorial on YouTube about cohesive visualization. But something went wrong, got a error in job submission:

A boundary condition has been specified on node set assembly_set-1 but this node set is not active in the model
Node set assembly_set-1 has not been defined

Can anyone take a look what I did and give some advices?

Thanks in advance!!

 

[FEA way]

You applied a boundary condition to the reference point without connecting it to the sphere. That's what causes the error. Apart from that, you should also fix the other sphere and add Cohesive Behavior to contact property.

 

[CKJK]

Hello, I have no idea how to connect the reference point to my sphere. I watched a tutorial video on YouTube "Abaqus Standard: Contact Tutorial: Plane Stress", and did not see what else he did, do you mind to teach? Thanks!!

 

[FEA way]

You can use kinematic coupling constraint to connect reference point with the geometry of the model. But in this case it would be better to apply initial velocity (predefined field) to the whole sphere.

 

[CKJK]

But I the errors cannot be solved? Even though applying a velocity on the sphere with reference point. Do you mind edit on my file? Thank you!

 

[CKJK]

I searched and tried kinematic coupling constraint method, but an error: Too many attempts made for this increment

I guess there might be some settings I gave that were not reasonable?

 

[FEA way]

Change the step type to dynamic explicit, apply initial velocities to the spheres and add Cohesive Behavior to contact property (in Abaqus/Explicit you have to use general contact with individual property assignment to utilize surface-based cohesive behavior). This will eliminate errors and the analysis should work fine.

 

[CKJK]

Oh thanks a lot! It seemed to be working, I totally forgot about the cohesive behavior, I saw that in tutorials but I assumed it was created in this file.