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Spatially varying displacement boundary condition-Analytical field

Spatially varying displacement boundary condition-Analytical field

Spatially varying displacement boundary condition-Analytical field

(OP)
Hello community,

I have the following simulation problem.
I want to simulate the motion of a rigid body along another deformable body.
The rigid body moves along a curve that is given by a function.
I need a way to implement this curve to Abaqus.
I insert the function via the analytical field toolset but it does not work.
Plus if I use a rigid body constraint no analytical field can be used because I
get the message that the displacement equals to 0 due to the analytical field.

Any ideas?
Any help would be most appreciated.


Thanks in advance.

RE: Spatially varying displacement boundary condition-Analytical field

(OP)
Thank you very much for your answer.
Problem is that this time I can not simulate the curve via many lines because my tool is a lot smaller than the
previous one and I also need the tool to be vertical to the curve at the same time.
This is why I need a new method to apply my spatially varying displacement BC and the tool I need is analytical fields.


Thanks in advance.

RE: Spatially varying displacement boundary condition-Analytical field

Sorry, I'm not getting what you want to do. Try to explain it better and maybe with an image.

RE: Spatially varying displacement boundary condition-Analytical field

(OP)
If I use two different amplitudes to describe the displacement in the two axis, as you have advised, I virtually give many (as much as the lines of the amplitudes) linear displacements along the two axis.
My goal is however, to insert to the program a displacement boundary condition that is not uniformly distributed but rather follows a curve that can not be simulated accurately by many linear displacements.
So, I am now looking into the analytical field toolset to insert the curve's equation right into the the boundary condition.


Again, any kind of help would be highly appreciated.
Thanks in advance.

RE: Spatially varying displacement boundary condition-Analytical field

Use Amplitudes of type Smooth Step. It creates a 5th order polynom. See Manual for more details.

A user subroutine DISP or VDISP would also be an option.

RE: Spatially varying displacement boundary condition-Analytical field

(OP)
I am aware of the smooth step amplitude but in the manual it clearly states that the smooth step definition cannot be used to interpolate smoothly between a set of data points.
Also I was looking for a way to avoid using subroutines but it seems it is unavoidable.

Thank you very much for all your answers.

RE: Spatially varying displacement boundary condition-Analytical field

I didn't say that a interpolation is happening.

When you create a table with many time points and use a smooth step amplitude with that, I cannot believe that this is not good enough. What procedure are you using, what is the time period and what's the typical increment size in there?

RE: Spatially varying displacement boundary condition-Analytical field

(OP)
I created a table with 100 time points for each displacement axis along with a smooth step amplitude and I get the error :
'The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element'
If I use less points the job is working but not at the required curve precision.

My step time period is 0.01 seconds and the maximum size increment is 10^(-6)

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