Want to find moment reaction in ansys

- April 18, 2019 at 10:00 am
  
  devendra
  Subscriber
  
  hello everyone,
  
  I want to calculate the moment over a part of a mechanism while applying force on another part of the same mechanism. my mechanism consists of 9 parts as shown below. I have tried to show joints and axis of revolution using a black line I hope you understand.
  
  as shown above, I want to apply force over a part and want to see the moment over another part in this mechanism. I want to know what type of analysis I should choose and what step I should go through. Please help.
- April 18, 2019 at 11:31 am
  
  jj77
  Subscriber
  
  If you have a e.g., bonded contact between parts (or at supports) one can get the total force reaction and moment reaction there.
  
  http://www.padtinc.com/blog/the-focus/using-probes-to-obtain-contact-forces-in-ansys-mechanical
  
  Or one can also get it on a surface cut through the solid body.
  
  See here for details:
  
  https://www.simutechgroup.com/tips-and-tricks/fea-articles/166-fea-tips-tricks-ansys-force-construction-geometry-surface
- April 18, 2019 at 1:27 pm
  
  devendra
  Subscriber
  
  thank you jj77 for your help.
  
  But will it be good to use bonded contact because in this mechanism all joints are revolute. The part where force is applied when rotates it causes rotation in the other part where I want to find moment or vice versa. If I will use bonded contact then the mechanism will not work as I wanted to because (if I am correct) joints will behave like rigid welded joint causing my mechanism to behave like a solid.
  
  please suggest me something...
- April 18, 2019 at 2:08 pm
  
  jj77
  Subscriber
  
  it was just an example not literally. One can perhaps calculate reaction at joints also, using the Joint Probe (never used it but try it).
- April 18, 2019 at 4:51 pm
  
  devendra
  Subscriber
  
  Thank you very much jj77 for all your help. I have one more question, what type of analysis I should prefer? since I can't calculate moment reaction in rigid dynamics. Hence I have to options static structural and transient structural, which one should I use.
  
  Again thank you for trying helping me out.
- April 18, 2019 at 5:30 pm
  
  jj77
  Subscriber
  
  If you do need to account for dynamic effects that include inertial effects, basically mass*acc., (which I doubt), use transient, otherwise use static.
- April 19, 2019 at 12:24 am
  
  peteroznewman
  Subscriber
  
  devendra,
  
  I see you have a mechanism. I would expect that the Rigid Dynamics solver would be useful for this model. If you apply a Displacement = 0 load to the Revolute Joint to hold it fixed, then you can apply the force to the other body. The mechanism won't move, but the Reaction Moment will be calculated on the Displacement load. This computation will be very fast.
  
  If there is some reason why this doesn't work, you could do the same thing in Static Structural, but it will take more time to compute.
  
  If you want to attach a Workbench Archive .wbpz file to your reply, I can try it with your model.
- April 19, 2019 at 5:01 am
  
  devendra
  Subscriber
  
  Thank you very much #peteroznewman, I will try using both.
  
  Actually my main motive behind this analysis is to find minimum torque(will be provided by external motor) required on the part (over which I am trying to calculate moment reaction) to cause my mechanism to work. For this what I did is, first I calculated force due to gravity on the part(part over which I am applying force) and tried to calculate moment reaction on other part.
  
  Am I doing right?. Is this a correct way to approach this problem. If not please tell me the correct approach. (soon I will attach .wbpz file)
  
  once again thank you for replying.