Mechanical Characterization and Preliminary Modeling of PEEK
Poly-ether-ether-ketone (PEEK) is a high-performance semi-crystalline polymer with mechanical and thermal stability characteristics that are superior to most tough polymers. The mechanical characteristics of this polymer are modeled over a broad range of mechanical loading conditions using a thermodynamically consistent modeling process. This preliminary model, which ignores the thermal response and the possible recrystallization of this material during loading, shows an outstanding ability to capture the multidimensional nonlinear response of PEEK up to 60 % compression, with loading rates from 0.0001 to 3000 1/s at room temperature. The model includes the measured anisotropy in the wave response that develops with plastic flow, captures the evolution of the measured equilibrium stress, and correctly matches the evolution of the tangent modulus at equilibrium. This broad range of rates and experimental conditions are achieved by using a two-element nonlinear thermodynamically-consistent model.
KeywordsPoly-ether-ether-ketone (PEEK) Equilibrium stress Plastic flow Anisotropic elasticity Mechanical modeling
The research has been partially supported by the US Army Research Laboratory through Contract Number W911NF-11-D-0001-0094. The experiments performed during this project were completed by utilizing the stress analysis center facility of the University of Nebraska-Lincoln.
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