Old spec Statics Session 19 Example 1TutorialOld spec ENGR2162:210 min

ENGR216 (old spec) Statics session 19 worked example 1 (slides 8-10) official answers

A 2 m long steel column of solid circular cross section with radius r=40r = 40 mm has E=200E = 200 GPa and allowable normal stress σall=100\sigma_{all} = 100 MPa. Using a factor of safety k=2.5k = 2.5 on Euler's critical load for buckling, determine the maximum compressive axial load the column can carry if:

Formulas you may need
  • Euler critical stress σcr=π2E(Le/ρ)2\sigma_{cr} = \dfrac{\pi^2 E}{(L_e/\rho)^2}, ρ=I/A\rho = \sqrt{I/A} (on the formula sheet)
  • Effective lengths: pinned-pinned Le=LL_e = L, fixed-fixed Le=0.5LL_e = 0.5L (on the formula sheet)
  • Solid circle ρ=r/2\rho = r/2 (on the formula sheet: I=πr4/4I = \pi r^4/4, A=πr2A = \pi r^2)
  • Allowable load Pmax=min⁡(σcr/k, σall) AP_{max} = \min(\sigma_{cr}/k,\ \sigma_{all})\,A (learn this)
  1. (a)
    the column is pinned at both ends;
  2. (b)
    the column is fixed at both ends.