Question

7) A section of 4 inch x 4 inch x .25 inch thick tube steel is used as shown below and is anchored into concrete. Calculate the stresses at A and B as shown on the tube. (10 points) specifications for a 4 inch x 4 inch x 25 structural tube, Area 3.59 in2, 1-8.22 in', Sx-4.11 i SECTION AA 1,500. 16,

Answer 1

Given: A section of (4 times 4 times 0.25) inches thick tube steel is used as shown in figure below Specifications for this is: 4 inch times 4 inch times 0.25 structural tube, Area = 3.59 in^2 I = 8.22 in^4 S_xx = 4.11 in^2 The figure is as shown below The objective is to determine the stresses at A and B which as shown on the tube. Bending moment = 1500 times 36 = 54000 Stress at A: - Stress at point A is calculated as follows: sigma_A = P/A + M/S Substituting the values in above equation sigma_A = 1500/3.59 + 1500 times 36 = -417.827 + 13138.686 sigma_A = 12720.85 Psi Stress at B Similarly now we calculate stress at point B is calculated as follows: sigma_B = -1500/ 3.59 + (1500 times - 36/4.11) = -417.827 - 13138.686 sigma_B = -13556.513 psi