FRP Load & Span Calculator
FRP Grating Load & Span Calculator
Estimate simply-supported beam deflection for a 1-metre-wide strip of grating. UDL formula: δ = 5wL⁴ / (384EI). Point-load formula: δ = PL³ / (48EI). Molded E = 10,000 MPa; pultruded E = 20,000 MPa. Section I = b·h³/12 per metre width (b = 1000 mm).
1 · Inputs
Mesh size affects open area, fall-through and impact resistance; this simplified deflection model treats the panel as a solid strip, so mesh does not alter the estimate. Certified load/span charts differentiate mesh geometry.
Run the calculation to see a verdict.
Enter your inputs and press Calculate Deflection — PASS / FAIL, computed vs. allowed deflection, utilisation and a recommended next thickness.
What the Numbers Mean
| Output | Definition | How to Use It |
|---|---|---|
| Computed deflection δ | Predicted mid-span sag under the applied load (mm). | The actual sag the panel would show, per the simplified beam model. |
| Allowed deflection | L / deflection-limit ratio (e.g. L/150 = span ÷ 150). | The sag your chosen code permits. Compare computed vs. allowed. |
| Utilisation % | Computed deflection ÷ allowed deflection × 100. | Below 100% = PASS. Approach 100% = no reserve; above 100% = FAIL. |
| Recommended thickness | The next panel thickness that meets the limit at the same span. | If the current panel fails, step up in thickness (or move to pultruded). |
Need the Certified Load Chart?
Send your span, UDL, point load and deflection limit — we return the exact panel and the certified load/span table.
Design basis: ZeAllgrate (Fiberglass Grating Manufacturers Council / ACMA) design guidelines; ASTM D790 (flexural properties), ASTM D638 (tensile), ASTM D648 (heat deflection) and ASTM E84 (surface burning). Resin property data based on Ashland / Reichhold technical datasheets. All outputs are INDICATIVE estimates for specification guidance only — they are NOT a substitute for certified load/span charts, approved resin datasheets or professional engineering judgment. Final design must be verified by ZeAllgrate engineering.