A rectangular bar of length L has a slot in the central half of its length. The bar has width b, thickness t, and elastic modulus E. The slot has width b/3. The overall length of the bar is L = 560 mm, and the elastic modulus of the material is 68 GPa. If the average normal stress in the central portion of the bar is 210 MPa, calculate the overall elongation ō of the bar. Answer: Ō = b F 2 6/3 mm

Question 1 A steel bar with length of 4.5 m is subjected to forces as shown in the figure: 1. Determine the stress in the square section 2. Determine the elongation of each sections Take the modules of elasticity for the bar is 200 GPa Circular section Square section Circular section Diameter =15 mm Area =20 mm*20mm Diameter =10 mm 50 kN 35 kN 30 kN 45 kN 1 m 2 m 1.5 m

A symmetrical framework consisting of threepin-connected bars is loaded by a force P (see figure).The angle between the inclined bars and the horizontalis α = 52°. The axial strain in the middle bar ismeasured as 0.036.Determine the tensile stress in the outer bars ifthey are constructed of a copper alloy having the followingstress-strain relationship:σ = 18,000ε/(1 + 300ε)        0 ≤ ε ≤ 0.03 (σ=  ksi)