Strength of Perforated Metal Sheet & Panels

materials
panel-shapes

 

Perforating sheet metal reduces the yield strength of the sheet metal significantly.
For a typical ‘T’ pattern perforation at 40% open area , e.g. 10mm dia at 15mm staggered pitch, the strength will be approximately 27% of solid when measured parallel to the straight rows of the perforated pattern, and 33% of the strength of solid sheet measured perpendicular to the straight rows of holes.

Obviously any plain margins around the perforated area will increase the overall strength of a perforated panel and folded edges will add further rigidity.

The graph and table below show guidelines for estimating strength of perforated sheet metal for standard T pattern /60 degree stagger perforation at various open areas.

standard T perforated pattern2
yield-strength-ratio-perforated-sheet2

Strength of Perforated Metal

% open areaS*x/S parallel to straight rowsS*y/S perp to straight rows
200.5300.465
230.5000.435
300.4280.363
320.4000.334
330.4000.334
360.3750.310
400.3330.270
440.3000.239
460.2880.225
480.2730.214
500.2580.200
510.2500.192
540.2310.175
580.2000.147
S – Yield strength of solid (unperforated material)
S*x – Yield strength parallel to straight rows of holes
S*y – Yield strength perpendicular to straight rows of holes