TITLE:
Fatigue Life Analysis of Fixed Structure of Posterior Thoracolumbar Pedicle Screw
AUTHORS:
Tong Yang, Kai Chen, Yonggui Lv
KEYWORDS:
Pedicle Screw; Stress; Fatigue Life
JOURNAL NAME:
Engineering,
Vol.5 No.10B,
October
31,
2013
ABSTRACT: In order to analyze the fatigue life of the posterior
thoracolumbar fixed structure, a loading model was established in accordance
with the anti-fatigue test requirements specified by ASTM Standard F1717-04. Two
three-dimensional Models of the fixed structure with two bars and four bars
were built by 3D software (UG), and imported into ANSYS software for static
analysis. The maximum and minimum stresses of risk nodes under different loads
and moments were obtained. The fatigue life was then calculated using relevant
mathematical formula of S-N curve and Goodman curve. It was found that the
stress at the middle of the crossbeam between the two bars is larger than the
surroundings and is liable to suffer from fatigue.