Learning Forum

[AhmedCfx]

Hi all,

 

How can I add damper instead of a bar in Static structural/ workbench as shown in image?

 

Thanks in advance

[peteroznewman]

Do you mean to remove the bar the arrow is pointing at and have a spring/damper that goes between the current ends of the frame?

You would do that by deleting or suppressing that body in the CAD system.

Then in Mechanical, under the Connections folder, you would add a Spring.

Springs have Longitudinal Stiffness and Damping.

However, the Damping is not useful in a Static Structural analysis. 
Damping only generates force when there is velocity between the end points.
Damping is there for use in Dynamics models such as Transient Structural, or Harmonic Response.

 

[AhmedCfx]

Thanx a lot it really works

[AhmedCfx]

 Thanks Mr peteroznewman

If I could ask you another question how can use MRE damper instead that damper ?

 

Thanks in advance 

[peteroznewman]

What are the properties of your magnetorheological elastomer (MRE)?

[AhmedCfx]

MRE sheet 4mm thickness with outer diameter 110 mm and inner diameter 90mm conical-shape, 600 turns maximum current 2A , flux 0.62T 

harmonic inputs with amplitude (- and+0.2mm) and frequency 0.5 under different current 0.5 , 1, 2, 3, 

[peteroznewman]

Please complete the geometric specification. You say an OD and ID and conical-shape.  What is the length? What is the OD at that length?

Please complete the elastomer specification. What material model do you have to describe the elastomer? There are many available in the Engineering Data library.

Please complete the magnetic particle specification? Are the magnetic particles polarized? What direction? What is the magnetic field strength?

Please complete the definition of the coils. How are the coils arranged relative to the cone?

The above would allow you to build a model to simulate the force-displacement data for the spring/damper at different currents. Alternatively, you could put a physical prototype into a Tensile/Compressive testing machine and test at the set of currents you mention. Do you have any test data?  You can use that in a nonlinear spring definition.

Do you have any research papers on MRE damper simulation?

This paper has a diagram of an MRE, it has no cone.

[AhmedCfx]

Dear Sir
I want to add MR damper instead of two members. This damper depend on deformation feedback, when deflection increase damping ratio increase too.

[peteroznewman]

Okay, but you didn't answer any of the questions in my last post.

[AhmedCfx]

Mr peteroznewman I’ve changed it to the new one as shown in the attached image

[peteroznewman]

I suggest you characterize your model of the MR damper without the structure you want to assemble it into. Just fix one end and move the other end. Please show your model of that.