Bonded contact not working

- July 21, 2022 at 7:39 pm
  
  greena18
  Subscriber
  
  I'm trying to make a bonded contact between two bones in explicit dynamics so that when I impact one bone, the other will move with it/be affected by that impact. I started experimenting in static structural to see if this would work (picture attached), and it did. Then I moved to a simplified version of my scenario in explicit dynamics using beams instead of bones (picture attached), and this worked as well. But when I used two bones in explicit dynamics, made the bonded contact, and applied the force, the sim went crazy (picture attached). Does anyone know why this might be happening, and how I can recreate my results from static structural in explicit dynamics? Something to note is that I got the message "time step too small" when I ran that third simulation
- July 22, 2022 at 6:29 pm
  
  Chris Quan
  Ansys Employee
  
  In Static Structural system, force is static. In Explicit Dynamic system, force is dynamic (impact) and thus will cause higher stress and larger deformation than the same force applied in Static Structural system.
  How did you apply the force? Was it a step load? If yes, can you ramp up the force with time from 0 to its full magnitude in the force BC?
  What is the material model used for the bones? Does the same material model works with both Static Structural & Explicit Dynamics systems?
  If you found that two bodies were not bonded together at their interface, you can increast its Offset in the bonded contact to make them bonded. Then you can use user-defined results Bond_Status to verify if they are bonded (Bond_Status > 0).