1. The problem statement, all variables and given/known data The length of a unstressed girder is found to be 1.2m at a temp of 20 oC. A tensile load is then applied and some time later the temp is 50 oC and the length of the girder 1.202m evaluate: (a) the tensile stress due to the applied load in the girder. (b) the factor of safety that is in operation if the UTS for the girder is 550MN/m2 (c) the strain and hence the change in length of the girder, if the temp remains at 20 oC E = 200 GN/m2 coefficient of linear expansion = 12 x 10 - 6 2. Relevant equations X = length x coefficient of linear expansion x change in temp strain = coefficent of linear expansion x change in temp stress = modulus of elasticity x coefficient of linear expansion x change in temp stress = U.T.S/ F.S 3. The attempt at a solution (a) stress = 200 x 10 9 x 12 x 10 - 6 x 30 oC ( this is from 50 oC- 20 oC = 30 oC) = 72 MN/m2 (b) f.s = u.t.s/stress 550 x 10 6 / 72 x 10 6 = 7.63 (c) strain = coefficient of linear expansion x change in temp 12 x 10 -6 x 20 oC = 0.24 x 10 -3 if someone would be so kind to tell me if this correct it will be much appreciated.