Notched fatigue behavior of PEEK.
Poly(ether-ether-ketone) (PEEK) has been used as a load bearing orthopaedic implant material with clinical success. All of the orthopaedic applications contain stress concentrations (notches) in their design; however, little work has been done to examine the fatigue behavior of PEEK in the presence of a notch. This work examines both stress-life (S-N) fatigue behavior and the fracture behavior of unfilled PEEK under tension-tension loading in circumferentially grooved round bar specimens with different elastic stress concentration factors. It was found that the majority of the loading was elastic in nature, and that there was only a small portion on the lifetime where there was a detectable change in structural behavior prior to gross fracture. Fractographic analysis via SEM further elucidated the potential fracture micromechanisms. Additional analysis was conducted to estimate the percent of the lifetime spent in crack initiation vs. propagation, and it was found that the specimens spent the majority of the time in the crack initiation phase.
Sobieraj
Michacl C
MC
Musculoskeletal Mechanics and Materials Laboratories, Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA. michael.sobieraj@nyumc.org
Murphy
James E
JE
Brinkman
Jennifer G
JG
Kurtz
Steve M
SM
Rimnac
Clare M
CM
D001577:Benzophenones; D007659:Ketones / Q000737:chemistry*; D008422:Materials Testing; D008962:Models, Theoretical; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D013314:Stress, Mechanical
D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols