Question

Each bar of the truss shown in the figure below has a diameter of 20 mm Suppose that P = 36 kN (Figure 1) Part A Determine the average normal stress in bar BC of the truss. Express your answer to three significant figures and include the appropriate units. Enter negative value in the case of compression and positive value in the case of tension. σ1e* Value Units Submit Request Answer Part B Determine the average normal stress in the bar AC of the truss. Express your answer to three significant figures and include the appropriate units. Enter negative value in the case of compression and positive value in the case of tension. ACVaue Units Submit Part C Determine the average normal stress in the bar AB of the truss. Express your answer to three significant figures and include the appropriate units. Enter negative value in the case of compression and positive value in the case of tension. Figure 1 of 1 σ | Value Units Submit 1.3 m < Return to Assignment Provide Feedback

Answer 1

Given that, d = 20mm p = 36kn at point c, F_Bc cos 36.86 = 36 F_Bc = 45 kN F_Bc sin 36.86 = F_Ac 36/cos 30.86 times sin 36.86 = F_AC at point A, F_Ac = 36 times 15/2 F_AC = 27 KN at point B, F_BC sin 36.86 = R_Br R_By = 27 kn F_AB = 36 kn sigma_AB = F_AB/A_AB = 36 times 10^3/1/4 times (20 times 10^-3)^2 = 114.59 mpa sigma_BC = F_BC/A_BC = 45 times 10^3/pi/4 times (20 times 10^-3)^2 = 143.23 mpa sigma_Ac = F_AC/A_kc = 27 times 10^3/pi/4 times (20 times 10^-3)^2 = 85.94 mpa sigma_AB = 114.59 mpa sigma_BC = 143.23 mpa sigma_AC = 85.94 mpa