Having problem when turn on the large deflection

- October 24, 2019 at 2:09 pm
  
  MubasherAli
  Subscriber
  
  Hi everyone!
  
  I am doing a static structural simulation for Spring using PA 12 materials. When I apply the load on the top of the spring and fixed with the bottom, also on the large deflection, it shows me such a warning message. I don't know what to do because I wanna use large deflection to analyze the stiffness variability
- October 24, 2019 at 2:23 pm
  
  Sandeep Medikonda
  Ansys Employee
  
  All of the nodal loads (forces, displacements, etc) in Ansys are applied in the Nodal Coordinate Direction. The "Large Deflection Key" tells Ansys to rebuild the stiffness matrix base on the current shape of the element. However, the Nodal Coordinate System does not get re-aligned: it stays in its original direction.
  
  Therefore, the geometry may have its shape altered, but the load stays in the original direction. This allows the potential for error.
  
  There are two methods that can be used to for this issue.
  
  -- Look and the maximum value of the displacement, if this value is "large" there is a potential problem. Now you need to define how large is too large. I typically use a value of 5 to 10%.
  
  -- Highlight the Solution Branch in the tree, and under Stress, you will find an error term. This will guide you to locations where the answers aren't very good.