Design and analysis of excavator bucket with movement - doesn't rotate!

[anacffaria]

Hello,

I'm new to Fusion and I'm having a problem I don't know how to tackle!
I mean to model a excavator bucket and do a stress and deformation analysis with the loads and considerations I have.
For that I modelled the bucket and attachments and I want to allow some rotation along a bar that I say it's fixed.
In conception I defined a revolute joint between the bar and the bucket and said the bucket had a range of rotation of -40º to 40º. The thing is that when I simulate there's absolute no rotation and the bucket just deforms in a strange way.
Attached are some images of what I've modeled so far.

Qhat am I doing worng? Is there any way to make it rotate the allowable amount? Is there a more appropriate way of designing this problem?

I really appreciate all the help!

Thanks, Ana

[jhackney1972]

You need to attach your model in order for the forum users to help you.  If you do not know how to attach your Fusion 360 follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save to your hard drive. Then use the Attachments section of a forum post to attach it.

[anacffaria]

@jhackney1972 I updated the post with the file. Thank you

[jhackney1972]

In the Design Environment, you model animates find within the joint limits.  If you are looking for actual rotation in the Simulation, then I am not the one to comment.  From your post I thought your issue was applying Joints.  I will have to leave it up to someone else.

[Ajay_Kumar_Reddy]

Hey @anacffaria,

You need to apply the pin constraint to account for the pivot.

see the attached model and animation video.

Also, there are potential issues with the geometry.

1. There must be no interference

2. Simplify the geometry for such edits

3. make sure that there is contact between parts, attaches, and palle is having clearance.

-40 to +40 degree rev animation can be by using the joints.

when it comes to FEA the loads and constraints will ensure the design safety, displacement, etc.,

[Anonymous]

Hi @Ajay_Kumar_Reddy !

I work with @anacffaria on this project. Thank you very much for your help.

I made some modifications on the design as you had suggested. You will find the file updated enclosed. But we have some questions regarding the modified file that you shared. 

First, about the constraints and the loads: can you explain why you put the constraints as you did on both simulations? And why have you changed the loads that we applied to put only one, that is lower than ours? Because, in our file, the two forces that go out of the bucket represent the force of the pistons and the one that goes into the bucket is the soil load when it is digging.

Also, do you think that we have to consider the gravity in our study? If not, why?

And last thing, when we put our loads, the ones that are more important than the one you put, we can see that the bucket deforms more on one side than the other side. In fact, it happens the same thing in your second simulation. If you adjust the result at x5, you can see this difference between the left and right part of the bucket (see the screenshot attached).

Thanks again for your help!