Fast Fatigue Testing of Spinal Implant Systems by the Load Stage Product (LSP)-Test Method

2004 ◽  
Vol 35 (12) ◽  
pp. 983-986
Author(s):  
U. Holzwarth ◽  
S. Lorenz ◽  
A. Schuh
Author(s):  
Denis J. DiAngelo ◽  
Geza Osztheimer ◽  
Kevin T. Foley

Anterior cervical instrumentation used in discectomy or corpectomy graft fusion should restore the mechanical integrity of the operated spine and decrease graft complications. For fusion to occur, the spinal instrumentation must load-share with the interbody graft. Recent design changes in anterior cervical plates (ACP) aim to allow motion across the fusion site and load share with the graft [1]. However, existing American Society for Testing and Materials (ASTM) standards (F1717-96) for static and fatigue testing of spinal implant constructs in a corpectomy model do not include an interbody graft in the test method [2]. The objective of this study was to develop a non-destructive testing protocol and apparatus to rank the static and low-endurance performance of ACP instrumentation in single-level discectomy and corpectomy graft-plate models.


2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.


Sign in / Sign up

Export Citation Format

Share Document