Failures

Failures describe material failure criteria to be coupled to material models.

In Radioss, Failure models are defined with the keywords /FAIL.

Failure entities have a display state, on or off, which controls the display of these entities in the graphics area. To hide or show a Failure entity, the “Hide Attached” option in the Model Browser configure window, must be activated. The display state of a Failure entity can be controlled using the icon next to the entity in the Model Browser.

Failure entities also have an active and export state. The active state of a Failure entity controls its display state and its listing in the Model Browser along with its views. If a Failure entity is active, then its display state is available to be turned on or off and it is listed in the Model Browser along with its views. If a Failure entity is inactive, then its display state is turned off permanently and it is not listed in the Model Browser or any of its views.

The export state of a Failure entity controls whether or not this entity is exported when the custom export option is used. The all export option is not affected by the export state. The active and export states of Failure entities can be controlled using the Entity State Browser.

Radioss Cards

Card Solver Description Application Notes
/FAIL/BIQUAD Strain failure model Ductile metal Direct input on effective plastic strain to failure
/FAIL/CHANG Chang-Chang model Composite Failure criteria for composites
/FAIL/CONNECT Failure Connection spot weld Normal and Tangential failure model
/FAIL/EMC Extended Mohr Coulomb failure model Metal Failure dependent on effective plastic strain
/FAIL/ENERGY Energy isotrop Metal, plastic Specific energy
/FAIL/FLD Forming limit diagram Metal Forming Fld
/FAIL/HASHIN Composite model Composite Hashin model
/FAIL/JOHNSON Ductile failure model Ductile metal Johnson-Cook
/FAIL/LAD_DAMA Composite delamination Composite Ladeveze delamination model
/FAIL/NXT NT failure model Metal Forming Similar to FLD, but based on stresses
/FAIL/PUCK Composite model Composite Puck model
/FAIL/SNCONNECT Failure Connection, spot weld Failure criteria for plastic strain
/FAIL/SPALLING Ductile + Spalling Ductile metal Spalling + Johnson-Cook
/FAIL/TAB1 Strain failure model Ductile metal Based on damage accumulation using user-defined functions
/FAIL/TBUTCHER Tuler-Butcher model Ductile metal Failure due to fatigue
/FAIL/TENSSTRAIN Traction Metal, plastic Strain failure
/FAIL/USERi User failure model n/a n/a
/FAIL/WIERZBICKI Ductile material Ductile metal Bao-Xue-Wierzbicki model
/FAIL/WILKINS Ductile failure model Ductile metal Wilkins model
/FAIL/XFEM XFEM (Extended Finite Element Method