A 6m solid rectangular (50mm wide and 100mm deep) simply supported beam supports two point loads applied centrally in the x and (negative) y direction as shown below There is a 1.5mm gap between the beam and an adjacent rigid wall when the temperature is 15°C. Assume the roller support at A allows free movement in the z direction, but provides translational restraint in the x as well as the y direction. Assume the pin support at B provides translational restrain in all three directions.

1. (a) Determine the maximum compressive and tensile normal stresses that can occur in the beam as a result of the two applied point loads, at a temperature of 15°C.
2. (b) The temperature increases to 45°C. Determine the average normal thermal stress developed in the beam AND the new maximum compressive and tensile normal stresses. Assume Est = 200GPa, st= 12×10-6/oC.