Question

4.3 A laboratory test involves "potting" part of the femur in cement and then applying two loads f, each at a distance d from the centerline (cf. Fig. 4.4); this yields a couple or twisting moment 10-24. A strain gauge is placed at an angle α on the bone a distance L/2 from the fixed end. Derive a formula for the strain in the gauge that can be related to experimentally measurable quantities. Assume the bone exhibits a LEHI behavior and that it has a cross section at z- L given by inner and outer radii of a and c. Discuss for what such an experiment could be utilized. Discuss why the strain gauge is not applied at length L and angle α 0. 4.4 For a solid shaft of diameter d for z [O, 2L/3) and diameter nd for z (2L/3, L], subject to torques To at 2L/3 and 2To at L, (a) find the value of n such that the maximum shear stress σ:0 is the same in each segment and (b) find the twist Θ at the free end if n-1

Answer 1

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