ANSYS Workbench - Spreader - Lifting simulation (Stress)

[SukiLeinen]

I have STEP model of simple spreader (I beam) with two lifting lugs for my home assigment. I want to simulate liffting of 2 ton load with my spreader. How to simulate lifting (lifting chains)in Ansys Workbench 16 only to transfer movment. What constraints to use. I don't need stress in lifting chains or lifting equipment, only in spreader and lifting lugs (When spreader is loaded with 2 ton load).

Thank You very much.

 

[SukiLeinen]

Thank You. I will try to find tutorials on that. One question is it possible to create sketches on imported step file for example ?

 

[L_K]

If you have the model in CAD software, you can create the lines there and include also them in the step file. Or
after importing step file you can do any operations in DM.

 

[SukiLeinen]

Having trouble to import parts with sketched lines. I have imported it but it says volume 0 when trying to calculate. I have added this as command object:

ET,matid,LINK 180 (part LINK ans 180 are without space but if I leve it with space forum adds link )
KEYOPT,matid,3,1
SECTYPE,matid,LINK
SECDATA,area


Also I have figured out how to add spring element. Now I am trying to cope with data that I need to define there

 

[L_K]

When I did a test model using LINK 180 elements, I noticed that I had to assign a cross section to the line body
in DM even though in Mechanical it is defined again in the command object (SECDATA). If I didn't do that there was
a question mark next to the body.

 

[SukiLeinen]

Yes. Same thing here.I also want to try both approaches just to learn. Spring with high stiffness is from my point of view also very good solution for my problem. One silly question, with springs which part defines end of the spring that is going to lug and which part defines end that will be fixed in air - Reference or Mobile.

I have uese Body-Ground Scope, and placed my springs. But when I run analysis springs are not at the initial location, and model is deformed with large deformation. Model deforms sideways not in direction in which force is acting.


When I setup my LINK 180 try I get this error:

If one or more parts of the model are held together only by contact
verify that the contact surfaces are closed. Also make sure that
there are constraints (or friction) in the sliding direction even if
no load is applied in that direction. You can use the CNCHECK command
to check the initial contact status in the SOLUTION module.

Seams I am not constraining it well. I have created two bonded regions between lug inner surface and link 180 element and fixed link elements in
their intersection point but still this error is present.

 

[L_K]

If ground-body scope is used, reference side is fixed.

You should not see horizontal movement if both geometry and loading are symmetrical.
In case of horizontal movement, you can add a constraint to prevent it. In that case you should
check the force reaction of that boundary condition. The force reaction should be insignificant
compared to the loading.

Using LINK 180 element poses many problems. As you can see from VM31, a small initial strain
is input to give some initial stiffness. Also large deflections are activated. In order
to get the elements to work in your analysis, you might have to do the same. Also
the contact modelling might be problematic.

I suggest you to send the model to your local Ansys provider. They are usually really
resourceful when it comes to implementing command objects and new elements
to Workbench. Also the before mentioned xansys mailing list is a good resource.