applying multiple loads using an orphan meshed model

[irishcanadian]

I am trying to apply loads to the distal end of a whole bone model using ex vivo pressure mapped data. I want to apply multiple loads according to the areas of contact in the joint but am having difficulty selecting sections where I want the load to be applied. Is there a way to select an area (multiple nodes) on the surface without having it penetrate the entire model or do i need to select the areas on an element by element basis?

 

[IceBreakerSours]

I am assuming you are a beginner. So, this is how I think you should go about it. This process makes your INP file more readable as well.

1) Tools -> Surface -> Create -> Name it
2) In the message dialog box below where it says "Select the regions for the surface", you can choose "individually" or "by angle" from the drop-down menu. By choosing an appropriate angle (and the manipulating the view), you can select a bunch of elements in one click. Ctrl+left mouse click will unselect elements whereas Shift+left mouse click will select elements.
3) Load -> Create -> Name it -> Choose appropriate step -> Choose the appropriate category and type of load.
4) In the message dialog box below (right corner), click on Surfaces -> Select the surface that you created in step 2 -> Check "Highlight selections in viewport" to make sure you are picking the correct surface.
5) Assign appropriate spatial distribution, magnitude and amplitude.

After you run the job, open the INP and find the surface you created. The more you play with it, the more sense it will make.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[irishcanadian]

Thank you for the response. Yes, I am new to FE modelling and am trying to negotiate my way through the program. This worked well for my model, so thank you again!

 

[irishcanadian]

Re: IceBreakerSours
I've tried creating both surfaces and sets in the parts and assembly modules however when I go to the load module and create a load there is no option to use the surfaces nor the sets I have already defined. I'm currently using Abaqus version 6.8-2 and am wondering if this is occuring because it is not the latest version. Being that I'm using an orphan mesh, this shouldn't be an issue should it?

 

[IceBreakerSours]

When you are at step 4 (above), does ABAQUS ask you for region type in the message dialog box? Since you are dealing with an orphan mesh, I assume you must be selecting "Mesh". In the right corner, don't you see a button which says "Surfaces"? I guess if you aren't seeing these options, then it must be a version related issue. In that case, forget about creating a surface first.

You can simply use "step 2" to select an element surface when you are assigning a load.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[irishcanadian]

RE: IceBreakerSours
Yes I am selecting MESH and no, there is no option in the right corner. There is a Sets.. button but once opened is not recognizing the sets I defined earlier in the parts nor the assembly module. I'm guessing it is because the version I am using is old. Thank you though!

 

[IceBreakerSours]

I don't know why but I assumed you wanted to apply pressure to the distal end of the femur. "Surfaces" button will appear IF you are applying a pressure - which makes sense since pressure must be applied to a surface.

Now, if you are applying, say, a load on a set of nodes, then "Sets" button will appear. If you created this node set previously, then it will appear in the "Sets" list.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083