고체역학 (Beer) — Pure Bending: Problem 4.112

4.112 A short column is made by nailing four 1 x 4-in. planks to a 4 x 4-in. timber. Using an allowable stress of 600 psi, determine the largest compressive load P that can be applied at the center of the top section of the timber column as shown if (a) the column is as described, (b) plank 1 is removed, (c) planks 1 and 2 are removed, (d) planks 1, 2, and 3 are removed, (e) all planks are removed.