Thin tube (20 mm inside diameter, 1 mm wall thickness and 100 mm long) is subjected to an internal pressure of 10 MPa as shown in Figure 1. If the uniaxial creep behaviour of the material is described by Equation (1), determine the increase in the diameter and length of the cylinder after 10 h. (Neglect end effects). E = 2.5x10 1oʻr4 (1) D P. Figure 1

50 mm PROBLEM 2.55 Brass 37.5 mm A brass link (E, = 105 GPa, a, = 20.9x10/°C) and a steel rod (E, = 200 GPa, a =11.7x10/°C) have the dimensions shown at a temperature of 20°C. The steel rod is cooled until it fits freely into the link. The temperature of the whole assembly is then raised to 45°C. Determine (a) the final stress in the steel rod, (b) the final length of the steel rod. 37.5 mm 0.12 mm -250 mm 30-mm diameter Steel A Section A-A 0, =-36.8 MPa L, = 250.147 mm %3D

A long metal plate (E = 210 GPa) with some cutouts in it is mounted between two rigid plates at 6 am. By noon, the temperature has risen by 20°C. The structure is made from aluminium with a coefficient of thermal expansion of a = 23 x 10-6/°C. Please use the stress concentration chart shown below for any relevant calculations. a10 h L b O Use the following values in your working out: K 3.2 3.0 2.8 2.6 2.4 2.2 2.0 L = 13 m 0 0.1 P 0.2 W W Javg 0.3 2r P (w2r)t 0.4 P ▬▬▬▬▬▬▬ 0.5 h = 5.3 m a = 0.8 m b = 1.6 m a) What is the average normal stress throughout the plate at noon? b) What is the maximum stress at any point in the structure? c) The material the plate is made from has a tensile yield stress of 416 MPa and a compressive yield stress of 200 MPa. Using these values, do you expect the plate to yield at/before noon?

A steel rod is rigidly attached to two walls as shown in the figure. If origin al temperature (T1) is 25°C, what is t he lowest temperature T2 that tempe rature can changed into without ther mal stress? The maximum yield of th e walls is 0.50 mm. A Steel Rod D = 100 mm L = 3.00 m a = 11.70 μm/(m°C) E = 200 GPa B