A Collapse Surface for Perforated Plates with Triangular Patterns for Ligament Efficiencies Between 0.05 and 0.50

Collapse surfaces are developed for thick perforated plates containing a triangular penetration pattern with ligament efficiencies of 0.05, 0.10, 0.15, 0.2, 0.3, and 0.5 using elastic-perfectly plastic FEA analysis. The FEA data was fit to a fourth-order collapse function which is appropriate for the development of an equivalent solid elastic-perfectly plastic plasticity model for perforated plates with triangular penetration patterns. This type of model can be conveniently used to develop a limit load capability for perforated plate analysis. It was shown that the fourth-order function is reasonable for ligament efficiencies between 0.15 to 0.5. Comparing the fourth-order collapse function to FEA data suggests that an alternate collapse function is needed for ligament efficiencies less than 0.15. A linear interpolation method was shown to be appropriate for ligament efficiencies between 0.15 and 0.5