BiQuad

This failure model uses a simplified nonlinear, strain-based, failure criteria with linear damage accumulation. The failure strain is described by two parabolic functions calculated using curve fitting from up to 5 user-defined failure strains.

1. Select BiQuad from the Select Failure list.
   • The chart changes to rupture strain vs triaxiality and plots the BiQuad curve. This failure criteria uses five parameters. Here you can select a material set it with default parameters. Shift the curve only by the rupture strain. The characteristic curve always remains the same, only the rupture strain changes.
   • Select Advanced and the five fields can be manipulated by value and slider. The characteristic of the failure curve will change.
2. Define the failure criteria in the Select Outcome list and create the material card. If created, strain rates are taken into account.

   
   
   Figure 1. Failure BiQuad