The steel plane truss shown in the figure is loaded by three forces P, each of which is 490 kN. The truss members each have a cross-sectional area of 3900 mm2 and are connected by pins each with a diameter of dp = 18 mm. Members AC and BC each consist of one bar with thickness of tAC = tBC = 19 mm. Member AB is composed of two bars [see figure part (b)] each having thickness tAB/2 = 10 mm and length L = 3 m. The roller support at B, is made up of two support plates, each having thickness tsp/2 = 12 mm.
(a) Find support reactions at joints A and B and forces in members AB, BC, and AB.
(b) Calculate the largest average shear stress Ï„p,max in the pin at joint B, disregarding friction between the members; see figures parts (b) and (c) for sectional views of the joint.
(c) Calculate the largest average bearing stress Ï„b,max acting against the pin at joint B.

P 490 kN A 45 3 m 45 Support plate and pin Member AB (2 bars, eachFBC FBC at 45 AB AB Member AB Member BC Support plate Support plate (2 plates, eachP) Pin Load P at joint B is applied (b) Section a-a at joint B (Elevation view) to the two support plates (c) Section b-b at joint B (Plan view)