Appendix B - Helius PFA Result Outputs

This appendix provides a description of the results produced by a Helius PFA analysis. Currently, only the PFA Damage State variable is available for post-processing. This variable is computed or updated at each integration point within each finite element.

PFA Damage State

PFA Damage State is a real variable that represents the discrete damage state of the composite material. It assumes a finite number of discrete values between 1 and 3. The number of discrete values assumed by this variable and the interpretation of those discrete values depend upon the type of composite material (i.e. unidirectional or woven) and the specific set of material nonlinearity features employed to describe the material's response. The following tables provide the interpretation for each allowable discrete value of PFA Damage State for each possible combination of composite material type and set of material nonlinearity features.

Note: For analyses with progressive failure turned off (MATPFA field 14), the PFA Damage State variable is not available for post-processing.

Unidirectional Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (deactivated)
  • Energy-Based Degradation (deactivated)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
2.0 Failed Matrix, Undamaged Fiber
3.0 Failed Matrix, Failed Fiber

Unidirectional Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (activated)
  • Energy-Based Degradation (deactivated)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
1.25 Matrix Pre-Failure Degradation Level 1, Undamaged Fiber
1.5 Matrix Pre-Failure Degradation Level 2, Undamaged Fiber
1.75 Matrix Pre-Failure Degradation Level 3, Undamaged Fiber
2.0 Failed Matrix, Undamaged Fiber
3.0 Failed Matrix, Failed Fiber

Unidirectional Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (deactivated)
  • Energy-Based Degradation (activated)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
2.0 Matrix Post-Failure Degradation Level 1, Undamaged Fiber
2.038 Matrix Post-Failure Degradation Level 2, Undamaged Fiber
...
2.923 Matrix Post-Failure Degradation Level 25, Undamaged Fiber
2.962 Failed Matrix (Crack Saturation), Undamaged Fiber
3.0 Fiber Post-Failure Degradation Level 1
3.038 Fiber Post-Failure Degradation Level 2
...
3.923 Fiber Post-Failure Degradation Level 25
3.962 Complete Fiber Failure

Unidirectional Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (activated)
  • Energy-Based Degradation (activated)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
1.25 Matrix Pre-Failure Degradation Level 1, Undamaged Fiber
1.5 Matrix Pre-Failure Degradation Level 2, Undamaged Fiber
1.75 Matrix Pre-Failure Degradation Level 3, Undamaged Fiber
2.0 Matrix Post-Failure Degradation Level 1, Undamaged Fiber
2.038 Matrix Post-Failure Degradation Level 2, Undamaged Fiber
...
2.923 Matrix Post-Failure Degradation Level 25, Undamaged Fiber
2.962 Failed Matrix (Crack Saturation), Undamaged Fiber
3.0 Fiber Post-Failure Degradation Level 1
3.038 Fiber Post-Failure Degradation Level 2
...
3.923 Fiber Post-Failure Degradation Level 25
3.962 Complete Fiber Failure

Woven Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (deactivated)
  • Post-Failure Nonlinearity (not supported)
  • Energy-Based Degradation (not supported)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
1.4 Fill Matrix Failure, Undamaged Warp
1.6 Warp Matrix Failure, Undamaged Fill
2.0 Matrix Failure in Warp and Fill
2.2 Fill Fiber and Matrix Failure, Undamaged Warp
2.3 Warp Fiber and Matrix Failure, Undamaged Fill
2.7 Fill Fiber and Matrix Failure, Warp Matrix Failure
2.8 Warp Fiber and Matrix Failure, Fill Matrix Failure
3.0 Completely Failed

Woven Composite Material

  • Progressive Failure Analysis (activated)
  • Pre-Failure Nonlinearity (activated)
  • Post-Failure Nonlinearity (not supported)
  • Energy-Based Degradation (not supported)
Allowable Discrete Values for PFA Damage State Discrete Composite Damage State
1.0 Undamaged Matrix, Undamaged Fiber
1.057 Matrix Pre-Failure Degradation Level 1, Undamaged Fiber
1.114 Matrix Pre-Failure Degradation Level 2, Undamaged Fiber
1.171 Matrix Pre-Failure Degradation Level 3, Undamaged Fiber
1.229 Matrix Pre-Failure Degradation Level 4, Undamaged Fiber
1.286 Matrix Pre-Failure Degradation Level 5, Undamaged Fiber
1.343 Matrix Pre-Failure Degradation Level 6, Undamaged Fiber
1.4 Fill Matrix Failure, Undamaged Warp
1.6 Warp Matrix Failure, Undamaged Fill
2.0 Matrix Failure in Warp and Fill
2.2 Fill Fiber and Matrix Failure, Undamaged Warp
2.3 Warp Fiber and Matrix Failure, Undamaged Fill
2.7 Fill Fiber and Matrix Failure, Warp Matrix Failure
2.8 Warp Fiber and Matrix Failure, Fill Matrix Failure
3.0 Completely Failed
Parent topic: User's Guide for Autodesk Nastran