고체역학 (Beer) — Analysis and Design of Beams for Bending: Problem 5.145

5.145 Two cover plates, each 7.5 mm thick, are welded to a W460 × 74 beam as shown. Knowing that \(\sigma_{all} = 150 \text{ MPa}\) for both the beam and the plates, determine the required value of (a) the length of the plates, (b) the width of the plates. (From Figure P5.144 and P5.145: Uniform load \(w = 40 \text{ kN/m}\), beam length \(L = 8 \text{ m}\), beam is \(W460 \times 74\)).