(b) Figure 1 shows, the tensile engineering stress-strain curve for an aluminum alloy. Based on Figure 1, determine; (i) Yield strength (o) (ii) Ultimate Tensile Strength (ors) (ii) Young Modulus (E)

A component made of 7075-T6 aluminum alloy has an edge crack of 1.4 mm in length. Plane strain fracture toughness of this alloy is given as 27 MPavm. Geometrical factor of the crack is given as 1.2. (a) If this alloy is subjected to uniaxial tensile stress of 380 MPa, determine whether sudden brittle fracture occurs or not. (b) Calculate the maximum allowable crack size for this component in order not to be failed in brittle manner under a stress of 1000 MPa (Density of steel 7.85 g/cm³, 9.80665 N = 1 kg). Modulus of elastisity, GPa Ultimate tensile Yield strength, Alloy strength, MPa MPa 2014 Al alloy Bronze (92Cu-8Sn) High carbon steel Pure Titanium 97 186 380 72 110 152 380 615 215 240 330 107

Question 1 You are working on a design team at a small orthopaedic firm. You have been asked to select a cobalt- chrome-molybdenum (CoCr) material that will not experience plastic deformation under a specific mechanical test, as follows... A tensile stress is applied along the long axis of a solid cylindrical rod that has a diameter of 10 mm. An applied load of some magnitude F produces a 7x10-³ mm change in diameter (see figure below, original shape is blue, elongated shape is unshaded). Q1A-B: Calculate the transverse strain in the x-direction (Ex) associated with the reduction in diameter. Calculate the axial strain in the z-direction (₂) associated with the length increase.

(b) A cylindrical rod made from an unknown metal is 350mm long and has a diameter of 10mm. The rod is subjected to a tensile load. It experiences only elastic deformation and elongates by less than 1.0mm under an applied load of 19,800N. Could any of the four metals listed in the table below could be the unknown metal? If so which ones and why? Material Modulus of Yield Ultimate Elasticity / GPa Strength / MPa Tensile Strength / MPa Aluminium 70 255 420 alloy Brass 100 345 420 Copper alloy Steel 110 250 290 207 450 550

Calculate the ductility of this steel alloy in %EL.

In an engineering application, the material is a strip of iron with a fixed crystallographic structure subject to a tensile load during operation. The part failed (yielded) during operation and needs to be replaced with a component with better properties. You are told that two other iron strips had failed at yield stresses of 110 and 120 MPa, with grain sizes of 30 microns and 25 microns respectively. The current strip has a grain size of 20 microns. The diameter of the rod is 1 mm and the load applied is 100 N. What is the yield stress of the new part C and would you recommend it for operation? Select one: a. O b. 129.5, yes C. 133.5 MPa, yes e. 120.5 MPa, no d. 140.5, no 123.5 MPa, yes

Determine the tensile strength, yield strength and percentage elongation (% ductility) for an iron- carbon alloy with 0.76 wt % carbon composition. O Yield strength - 60000 psi : Tensile strength - 110000 psi: Ductility - 15% O Yield strength - 130000 psi : Tensile strength - 68000 psi;: Ductility - 10% O Yield strength - 68000 psi : Tensile strength - 130000 psi; Ductility - 10% O Yield strength 50000 psi: Tensile strength - 100000 psi: Ductility - 20% O Yield strength - 86000 psi : Tensile strength 150000 psi: Ductility 25%