... not a direct example of the current chapter 168 n A Textbook of Machine Design Distance of N.A from the top of the flange, yt = y = 28.2 mm Distance of N.A from the bottom of the web, yc = 90 ... We know that area of section at X-X, A = × 22 + × 19 = 123 mm2 144 n A Textbook of Machine Design The various distances are shown in Fig 5.14 We know that radius of curvature of the neutral axis, ... solid shaft of diameter (d), the polar moment of inertia, π π π × d4 + × d4 = × d4 64 64 32 π π × d4× = × τ × d3 T = τ× d 16 32 J = IXX + IYY = ∴ 122 n A Textbook of Machine Design In case of a hollow...