Defining Revolute joints for 1D line bodies (beam type)

- July 16, 2025 at 12:23 pm
  
  shaikosmanpasha
  Subscriber
  
  Hey Hi!
  How do I define a revolute joint for 1D beam elements. Is it through End Release or by the Connections>Joints>Revolute in Mechanical. I want to simulate one beam revolving around the vertex of another beam element.
  And how to simulate a four bar mechanism (line bodies) in Ansys Mechanical. If possible any video links for the same or Your thoughts on how to proceed would be appreciated.
  ThankYou!
  
  #End_Release #1D_Element_Model
- July 16, 2025 at 4:00 pm
  
  peteroznewman
  Subscriber
  
  If all you need is the freedom of movement about one axis and that axis aligns with one of the beam cross-section axes, you can achieve that using a beam end release, but I would not bother with that.
  There are many benefits of using a Revolute Joint insead. One is the ability to add loads to that joint such as a torque or displacement load. Furthermore, it is easy to orient the revolute joint axis independent of the beam cross-sections and to visualize the orientation to verify it is correct. Another benefit of the revolute joint over an end release is the ease of obtaining output data at the joint such as forces and torques.
  - July 17, 2025 at 5:48 am
    
    shaikosmanpasha
    Subscriber
    
    Thanks Peter for the reply. I am unable to get a result for the above. What are all the constrains that I am missing out for a Static Analysis. I wanted to simulate a pendulum type mechanism(One beam is fixed, another one revolves around the vertex of the first beam).
    - July 17, 2025 at 11:53 am
      
      Erik Kostson
      Ansys Employee
      
      Hi
      
      Can you post some screenshots of the issue or errors you are getting (show also BC and loads), so we can try and help.
      All the best
      
      Erik
    - July 17, 2025 at 12:08 pm
      
      shaikosmanpasha
      Subscriber
    - July 17, 2025 at 12:19 pm
      
      Erik Kostson
      Ansys Employee
      
      Hi
      That is great.
      
      Think the problem is a bit unstable and hence it can not solve espec. if a y force is applied and rotate it (static can not cope with that – transient is ok).
      
      Try and add a x-displacement instead of x-force (set also y=z=0), see if that solves. We can look at reaction to get x force after.
      
      Finally look at adding substeps to aid convergence.
      
      Of course feel free to open a support request (ACSS) and we will be happy to help (it is easier that way as we can look at your model, as we are not allowed to download any files here in the forum).
      
      All the best
      Erik