Contact between steel supports and concrete beam

- October 11, 2019 at 5:58 am
  
  vaibhavtaranekar
  Subscriber
  
  Hello everyone,
  
  I am trying to simulate a reinforced simply supported concrete beam analysis on ansys and would like to know what should be the connections set between the loading and support plates during 3 or 4 point bending test?
  
  Currently i have set all the 3 plates to Bonded + MPC but i am not sure if its correct as the bottom supports is not connected to the concrete can freely bend from there.
  
  What should be the connection set between Loading plate and the supports?
- October 11, 2019 at 11:20 pm
  
  JJ_Thompson
  Subscriber
  
  It depends on how much bending you expect at that bottom edge. If it is small such that you don't get sliding at that interface, then MPC bonded will do allowing for the necessary rotation. I am not sure if the default in workbench includes the rotational degrees of freedom of the target element in the coupling. You can check the ansys contact technology guide for this on MPC.
- October 12, 2019 at 12:37 am
  
  peteroznewman
  Subscriber
  
  Use Frictional Contacts to allow for a gap to open on one side of the pad as the beam bending develops. You could even put a large radius on the pads to allow the center to be a line contact with the beam at the center of the pad instead of two lines at the edges of the pad.
- October 12, 2019 at 4:17 am
  
  vaibhavtaranekar
  Subscriber
  
  Thanks for your reply, i have not seen anyone using frictional contact yet, many of the papers i have seen have preferred bonded only. i also want to ask if only the loading plate should be done bonded+mpc or we can apply it for bottom supports also?
- October 12, 2019 at 4:20 am
  
  vaibhavtaranekar
  Subscriber
  
  I previously tried no separation with mpc contact from dr dalyo's video, it used to work before but now a days the plates just move out of the plane and rotate in random directions. i am not sure which is the correct contact type of this concrete and steel bond.
- October 12, 2019 at 10:50 pm
  
  peteroznewman
  Subscriber
  
  No separation is a frictionless contact, so you need constraints such as symmetry to keep things from rotating away.
  
  No separation and bonded contact are linear contacts, so solve in one iteration while frictional contact is nonlinear and may need several iterations to converge on the correct gap condition.
- October 13, 2019 at 7:25 am
  
  vaibhavtaranekar
  Subscriber
  
  so what should be the correct way to simulate the beam problems? should i go for bonded + mpc for all the three plates? or different for loading plate and different for support plates?