Q1 (1 mark) Shape factors for tubes (This question does not require the use of charts.)

(a) Evaluate the shape facture for stiffness-limited design in bending of a square box

section of outer edge-length h-40 mm and wall thickness t=2 mm. Is this shape more efficient

than one made of the same material in the form of a tube of diameter 2r=40 mm and wall

thickness t = 2.55 mm (giving it the same mass per unit length, m/L)? Treat both as thin-walled

shapes.

(b)

Make the same comparison for the shape factor for strength-limited design.

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