HI, All,
I am new to Pro/Mechanica. I am trying a simple practice problem with composite shell elements.
I have a solid thin plate. Since I can not use "shell pair" as I can not assigned laminate property to a "Shell pair", I try to use the just the top surface. I assign the laminate property...
For Maximum stress and strain criteria, FS = 1/FI
For Tsai-Hill, FS = 1/Sqrt(FI)
For Tsai-Wu and Hoffman, you have to solve a quadratic equation for FS. There is no simple equations between FS and FI.
The default output for composite failure analysis is the "Failure Index". Is there any way to output the "Margin of Safety" or "Factor of Safety"? For Tsai-Hill or Maximum Stress Criteria, we can calculate the Facotr of Safety from failure index. However, with Tsai-Wu or Hoffman, it is not easy...
Thanks a lot. Then how can I calculate the failure index? Using the element stress or element force. I read the Nastran manual and it said that the element stress is, in general, not accrate. Is that true?
I was not able to recover the composite ply stress or failure index when I was running a transient analysis with either SOL 109 or SOL 112. I tried to set NOCOMPS to be 0, 1 or -1. Just no ply stress (I can get element stresses and element forces though). Anybody has this type of experience or...
