| Opening Geometry | Collapse Load (kN) | Difference in Strength (%) | |
| Beam without Stiffeners | Beam with Stiffeners | ||
| Rectangular | 206.07 | 648.48 | 214.7 |
| Square | 434.06 | 906.64 | 108.9 |
| Circular | 1.034.85 | 1.238.76 | 19.7 |