Jump to content

Help with FEM analysis


Naraic

Recommended Posts

Hey

 

I am currently sitting with a model of a robot i am planing to build for a project at school. It has been a while since i have used SolidWorks and i have never really used the FEM part.

 

I am trying to simulate stresses and the deflection when a force of 500N is applied to the tool part of the robot. But i keep getting errors in SolidWorks when running the simulation. I know that something is not properly defined and would like if someone with some knowledge in the field could give some guidelines/tips on how i can get this simulation running?

 

I have made on version with the tool modeled up very basic and one that is close to what we want (without the belt system and motor)

 

https://www.dropbox.com/s/9pnz1h1lthbouyy/Basic_tool.zip?dl=0

 

https://www.dropbox.com/s/4tq019za2hiriz8/Std_tool.zip?dl=0

 

Every tip will be greatly accepted as i learn more and more.

Link to comment
Share on other sites

Naraic, i took a quick look at the file and there are definitely some concepts that would help you out.

 

I assume the base of the L_arm, the angled pieces get welded(stoettenbein) onto the L and then onto the base(sokkel_plate) right? Under "connections advisor" you can add edge welds as a Connector between bodies. If you want to assume they are all ridged then you want to "bond" them with a bonded contact set at the faces where they meet. Right now the way you have it with Contact sets it is telling Solidworks that everything is a solid body, the base is fixed but the load is essentially just pushing objects around. nothing else is really located.

 

Also the simplified files aren't realistic. How are the components attaching to each other? I would start by analyzing an individual body like the "tool" and work on restraining it. There are way too many degrees of freedom in your assembly and i think you need to start from one end and work your way down. If the tool fails without considering the rest of the assembly it's not use running a long simulation. Solidworks has to mesh and solve all the degrees of freedom. You can run a simulation and simply omit other bodies or exclude them. I used toolfeste as a fixed body with a contact set between faces. Added bolted connections between it and the tool with a torque preload. I left your external load of 500N.

 

When i ran a 500N load on the tool(detailed model) with the above connections/fixes the part failed not taking into account the rest of the assembly. The end of the tool deflected over 50mm. The FoS at the bottom corner where the load bar meets the vertical bar was below 1 in several places.

 

I didn't spend the time looking at the assembly as a whole but the part carrying the load, i believe, needs a redesign if you are planning on 500N load.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...