Theses and Dissertations

Issuing Body

Mississippi State University


Shamsaei, Nima

Committee Member

Daniewicz, Steven R.

Committee Member

Horstemeyer, Mark F.

Date of Degree


Document Type

Graduate Thesis - Open Access


Mechanical Engineering

Degree Name

Master of Science (M.S.)


James Worth Bagley College of Engineering


Department of Mechanical Engineering


The fatigue behavior and cyclic deformation of polyether ether ketone (PEEK) subjected to various uniaxial cyclic loading conditions were experimentally investigated. These include constant amplitude and multi-block loading conditions at various frequencies with zero and non-zero mean strains. Under constant amplitude loading, increasing the test frequency generally resulted in longer fatigue lives for PEEK, while a minimal effect of tensile mean strain was observed. For all fatigue tests under fully- reversed multi-block loadings, pre-loading was found to have a significant beneficial effect on PEEK fatigue resistance irrespective to the load sequence. However, no obvious load history and sequence effect on fatigue behavior was observed for pulsating tension block loading tests. Additionally, three models; strain-based, strain-stress-based, and energy-based models, were correlated to the experimental data in this study. The energy approach was found to provide better fatigue life predictions for PEEK under constant and multi-block loadings with various strain ratios and frequencies.