Tools › Structures › Stress Concentrations › Row of Holes › Example
Infinite row of holes under tension across the row, D/s = 1/3: K_tn 2.031 against the Pilkey fit 2.032
| Tool | Row of Holes |
| Source | Pilkey, W. D. (2005). Formulas for Stress, Strain, and Structural Matrices, 2nd ed. John Wiley and Sons, Hoboken, NJ. Table 6-1, case 5 (fits to Schulz 1941 and Meijers 1967); Pilkey, W. D., and Pilkey, D. F. (2008). Peterson's Stress Concentration Factors, 3rd ed. John Wiley and Sons, Hoboken, NJ. Charts 4.57–4.59. |
| Level | Professional |
Problem
A 0.1 in plate carries 5,000 lb/in in y and contains an infinite row of 0.25 in holes along x at a pitch of 0.75 in. Find the gross and net stress concentration factors, the net-section stress and the stresses at mid-ligament.
Inputs to Enter
- N_xx = 0, N_yy = 5000 lb/in, N_xy = 0, t = 0.1 in (σ_yy∞ = 50 ksi)
- D = 0.25 in, s = 0.75 in (λ = D/s = 1/3)
- r = 0.125 in (hole edge), θ = 90° (on the row axis)
Answers
- K_tg = 3.0466 at θ = ±90° (series order N = 14); σ_edge at θ = 0: −37.28 ksi
- σ_n = σ_yy∞ s/(s − D) = 75 ksi; K_tn = 2.0311 (Pilkey fit 2.0318)
- Mid-ligament σ_yy = 59.82 ksi (0.798 σ_n), σ_xx = 16.03 ksi
Notes
The tool's default inputs are this case. Pilkey's Table 6-1 labels its cases (a)/(b) in conflict with its nominal stresses; the net-section polynomial is the load across the row.