Page 210 - Failure Analysis Case Studies II

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(4)
where h, = the radius of specimen 1, p, = the radius of curvature for specimen 1, h2 = the radius of
specimen 2, p2 = the radius of curvature for specimen 2. The equivalent radius of curvature for the
3/ 16" diameter specimens was calculated to be 1.5".
The handle holder manufacturer supplied several tool samples having typical bends used during
surgery (Fig. 3). The tools were bent by hand during testing just as they would be during surgery.
The 3/16" rods were bent to a predetermined angle (60") to simulate the worst case scenario during
normal use (Fig. 4). The first group of specimens (group 1) was tested by bending until failure in

Fig. 3. Handle holder with typical bends used in surgery. (A) Handle holder before bending. (B-F) Handle
holder with typical bends.
3,O"e) PIPE -,

BAR

Fig. 4. Experimental setup.