Pressure testing of large-scale torispherical heads subject to knuckle buckling

Abstract Two fabricated steel torispherical heads were tested under internal pressure to determine their buckling and rupture strengths. Both models had cylindrical diameters of 192 in, knuckle radii of 32·64 in, sphere radii of 172·8 in and measured thicknesses of 0·196 in (Model 1) and 0·270 in (Model 2). For Model 1, initial buckling was noted at 58 psi. Pressurization was continued to rupture at 229 psi. During the test, 14 buckles formed and a maximum strain of 3·5% was recorded in the spherical portion of the model. For Model 2, initial buckling was noted at 106 psi. Pressurization was continued to rupture at 332 psi. During the test 14 buckles formed and maximum strains of 4·3–4·7% were recorded in the spherical portion of the model.