고체역학 (Beer) — Pure Bending: Problem 4.120

4.120 The four bars shown have the same cross-sectional area. For the given loadings, show that (a) the maximum compressive stresses are in the ratio 4:5:7:9, (b) the maximum tensile stresses are in the ratio 2:3:5:3. (Note: The cross section of the triangular bar is an equilateral triangle.)