Answer Happy

A "rigid" beam AD is supported by a smooth pin at D and by vertical steel bars attached to the beam at points A and C. Neglect the weight of the beam. Element (1) was made to the correct length, and when only rod (1) is attached to beam AD, the beam is horizontal (i.e., 0=0°). Element(2), on the other hand, was fabricated shorter, and must be manually stretched to connect to the beam via a pin at C. This all happens before any other loads are placed. Once the bars are assembled to the system, a load P=30kN is added and the temperature of the bars is reduced by AT=30°C. Determine: a) The stresses in the bars (given in MPa). b) The angle of twist of the rigid bar AD (given in degrees, define the sense). For the two rods: L = 0,5 m a = 12 x10-6/°C A = 126,7 mm 8 = 0,5 mm E = 200 GPa a = 1 m a A1 = A2 = A, L1 = L2 = L E = E2 = E, b = 2a (2) L2 L (1) A B jua 9 "Rigid" -b aa