Ansys Workbench Displacement

panthalas

Hello, I am a new user both in Ansys and in the forum and I am sorry if my question is silly, but I cannot find the solution by myself.

I am using Ansys Workbench v.12 static structural in order to find the displacement of various parts of a robotic arm, that are caused by different loads.

I have successfully imported the geometry, made necessary changes, defined the connections, the load, the supports etc but I cannot find a tool that can calculate the Displacement of a certain part(the robot consists of many parts) .

I thought that the tool named Position which can be found in
Solution-->insert-->probe-->position would be the one I need, but the results it gives ,min and max value of a coordinate system (one I have placed on a face of the object whose displacement i want to find), are the same as if it didn't move at all.

Could someone please help me? Is this the right tool and I use it in the wrong way or is there another tool for that? I have attached a photo of the robot.

Thanks a lot

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Mech_Engineer

Just right-click the solution object and select "Insert - Deformation - Total". This will calculate deformation and displacement for all of the bodies in the system. You can also calculate diplacements along certain axes, and for specific bodies or features.

You're going to want to look into simplifying that geometry too, it's way too complex for the simple calculation you're trying to do (things like bolts can be removed for example). Also pay special attention to contact conditions- fixed conditions may not be what you're looking for at certain interfaces...

panthalas

Thanks for answering Mech_Engineer.

I have checked the contact conditions (rotations, fixed) and I think they are ok.

In order to simplify, I cut off unnecessary, conserning the strength, things like the bolts you told me.

Consider the fact that when the part I have indicated in the picture is loaded, the biggest deformation is that of the lowest and biggest joint. That deformation-most of all- results in the displacement of the indicated part (whose displacement I want to measure) . That's why I am asking for displacement and not for deformation.

You told me that the ''Total Deformation" tool calculates not only the deformation of the material in that place, but also the displacement of that. So, if I got it right, is that number the sum of deformation and displacement in a place? Does the same apply in the tool called "axial deformation" (in order to calculate the displacement in z-axis)?

About the position tool: is it irrelevant with what I am searching?

Thanks again!

Mech_Engineer

To get a pure deflection, you need to apply a result to a single point. Otherwise as you say, the deformation result is a function of deformation and deflection.

Mech_Engineer

By the way, what kind of a computer are you solving this on, and how big is your mesh?

panthalas

Ok then, I'll use the total deformation tool then. I am trying to calculate the sum of deformation and deflection at the part I showed in the picture.

The computer is strong: windows 7 ultimate x64, amd athlon II X3 425 processor 3,29GHz, 6GB ram, ATI radeon HD 4200.

The mesh I am using is the automatic Mechanical .I have changed the element size but I don't know what else to change. Check the attached picture. Is there anything you think I should change?

I have experimental data for this robot ( deflections in certain positions with certain loads). I am trying to make a model in Ansys that will have a close behaviour.

Thanks

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