A polymer screw is used as an anchor for a tendon replacement, and is heavily loaded. It
Question:
A polymer screw is used as an anchor for a tendon replacement, and is heavily loaded. It is found that the polymer creeps and slips out of the hole bored for it after an unacceptable short time. Experiments show that the Kelvin model describes the behavior of the anchor well over the time scale of interest, with Em = 500 MPa and hm = 20e6 MPa-s. What is the transition time of this material, and is it of interest? The borehole is 10 mm wide, and the interference fit is approximately 1 mm at time t=0. How long will it take for the screw to relax until the interference effectively reduces to zero when the interference pressure relaxes to 10% of its original value and the anchor slips out? Recommend some strategies to correct for this relaxation failure mechanism.
Applied Physics
ISBN: 978-0132109277
10th Edition
Authors: Dale ewen, Neill schurter, P. erik gundersen