3 m B 2 m A D 3 @4m = 12 24 KN E F

The truss below is : a.Unstable internally and unstable externally b.Unstable internally and stable externally c.Stable internally and stable externally d.Stable internally and unstable externally

The pin-connected structure consists of a rigid beam ABCD and two supporting bars. Bar (1) is an aluminum alloy [E = 61 GPa] with a cross-sectional area of A₁ = 810 mm². Bar (2) is a bronze alloy [E = 103 GPa] with a cross-sectional area of A2 = 470 mm². Assume L₁=2.4 m, L₂=3.1 m, a=0.7 m, b=1.9 m, and c= 1.1 m. All bars are unstressed before the load P is applied; however, there is a 5.8-mm clearance in the pin connection at A. If a load of P = 44 kN is applied at B, determine: (a) the normal stresses 0₁, 0₂, in both bars (1) and (2). (b) the normal strains &1, 82, in bars (1) and (2). (c) determine the downward deflection VA of point A on the rigid bar. A Answers: (a) 0₁ = (STVA = a i i B 156.10 0.00256 b C MPa, 0₁ = με, €2 = mm L2 i i D 20.75 0.0002014 MPa. με.

A2