Tools › Structures › Stress Concentrations › Row of Holes › Example
Infinite row of holes under tension across the row, D/s = 0.5: K_tn 1.621 against the Pilkey fit 1.628
| 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; 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
The same plate (5,000 lb/in in y, t = 0.1 in) has 0.25 in holes at a pitch of 0.5 in. Find the gross and net stress concentration factors.
Inputs to Enter
- N_xx = 0, N_yy = 5000 lb/in, N_xy = 0, t = 0.1 in
- D = 0.25 in, s = 0.5 in (λ = 0.5)
- r = 0.125 in, θ = 90°
Answers
- K_tg = 3.241: σ_edge,max = 162.1 ksi
- σ_n = σ_yy∞ s/(s − D) = 100 ksi; K_tn = K_tg (1 − λ) = 1.621 (Pilkey fit 1.628)
- Series K_tg across the row for λ = 0.1 … 0.9: 3.000, 3.006, 3.031, 3.096, 3.241, 3.546, 4.204, 5.755, 10.706 (fits within 0.5 % to λ = 0.7, +2.4 / +3.2 % at 0.8 / 0.9)
Notes
Change the default spacing to 0.5 in. Equal biaxial tension at the same ratio gives K_tg = 2.855; s = 1000a recovers Kirsch (3.0000 / −1.0000).