Question

3. Tubular samples of alumina having an inner diameter of 15 mm, outer diameter of 20 mm, and length 150 mm were tested by a uniaxial tensile loading condition. The breaking loads were recorded in kilo Newtons (kN) as 34.3, 28.3, 40.5, 18.2, 19.7, 33.8, 24.7, 16.5, 25.8, 21.9, 29.7, 39.7, 26.1, 28.5, and 17.7. Calculate the Weibull modulus and the breaking load for 50% survival probability. If the testing is result is used for recommending the maximum strength of a 'real-life' componen (a reactor tube) having dimensions of 200 mm outer diameter, 185 mm inner diameter and 1.5 m long, determine the design strength for 50% survival rate.

Answer 1

given di= 15mm L: 150mm do = 20mm dodi = 5mm Tmax = 40.5(KN) amax - 3 Pmax L. T & bn - 3 (40.5) C150 x16 ) I $ x 3 kapoo x 106 4.8xioo kw ama I > E - F L u bha 1-10cm => Ps(x) = I const J where Ps = m= weibull modules Probability of survival. 50 = 7 -om - 1.6989 CX 1.6989 - (1) - .581.6989 - 67m 849