4- The cross-section of the ABCD element in the figure is a circle with a diameter of 6 cm. The force of P-500 N is in the x-z plane. The CD segment is parallel to the y-axis. In line with the information given, a- Find the most critical points in section A. b- Calculate the normal and shear stresses at the most critical points in section A. c- Calculate the principal stresses at the specified points. d- Check the section with the Tresca Hypothesis. em = 95 MPa 75 cm B 50 cm C 40 cm

(3) The cantilever bar as shown on next page is made of a brittle material. At D, Fx-300 lb. F-250 lb, and F-100 lb. Determine the precise location of critical stress element at the cross section at A. Determine the magnitude for each of the stress components considering the stress concentration at A. Find the principal stresses and the maximum shear stress at this location. 2 in 1-in dia. -in R. 12 in

nc./Johan H σy 7.2-1 The stresses on the bottom surface of a fuel tanker (figure part a) are known to be o = 7750 psi, = 1175 psi, and 7 xy = 940 psi (figure part b). Determine the stresses acting on an element oriented at an angle = 55° from the x axis, where the angle is positive when counterclockwise. Show these stresses on a sketch of an element oriented at the angle 0. (a) PROBLEM 7.2-1 (b) 1175 psi Ţ 940 psi 7750 psi 7.2-5 The stresses acting on element A on the web of a train rail (see figure part a) are found to be 6500 psi tension in the horizontal direction and 18,500 psi com- pression in the vertical direction (see figure part b). Also, shear stresses with a magnitude of 3800 psi act in the directions shown. Determine the stresses acting on an element ori- ented at a counterclockwise angle of 30° from the horizontal. Show these stresses on a sketch of an ele- ment oriented at this angle. Cross Section (a) PROBLEM 7.2-5 B A Side View A (b) 18,500 psi 76500 psi 3800 psi

7.2-5 The stresses acting on element A on the web of a train rail (see figure part a) are found to be 6500 psi tension in the horizontal direction and 18,500 psi com- pression in the vertical direction (see figure part b). Also, shear stresses with a magnitude of 3800 psi act in the directions shown. Determine the stresses acting on an element ori- ented at a counterclockwise angle of 30° from the horizontal. Show these stresses on a sketch of an ele- ment oriented at this angle. Can Stock Photo Inc./corepics Cross Section PROBLEM 7.2-5 Can Stock Photo Inc./scanrail A Side View Sa A 18,500 psi T (b) 16500 psi 3800 psi