Q1. a. True or false? Marks: 2 (i) Fracture can occur from both fatigue and creep (ii) Crack propagates if applied stress is above yield stress which is also called critical stress (iii) The fracture toughness, KIC values are relatively large for ductile materials (iv) for cyclic stress, the cycles to fail increases as the stress amplitude increases Q1. b. Define the different terms of the equation below, where flaws and stress concentration are related as: (Marks: 1 ) m=2o(ta)1/2=Kto Here, t= o= Q2. If you design an engineering structure, will you prefer ductile fracture or brittle fracture? Write down at least two reasons why. (Marks: 3) Q1. c. A Steel rod of 78.5mm2 cross sectional area is subjected to a tensile load of 80855N, it has Klc of 54.8 MPa(m) - a handbook value. If it has a 'largest surface crack' .5mm(.0005m) long will it grow and fracture? What crack size will result in failure? K1C=Ya Marks: 4