Thermo-Mechanical Behavior of Poly(ether ether ketone): Experiments and Modeling.

Area of Science:

• Materials Science
• Polymer Science
• Mechanical Engineering

Background:

• Poly(ether ether ketone) (PEEK) is a high-performance thermoplastic with significant engineering applications.
• Understanding its thermo-mechanical behavior under various conditions is crucial for reliable design.
• Existing models may not fully capture the complex response of PEEK across a wide temperature range.

Purpose of the Study:

• To investigate the thermo-mechanical behavior of PEEK under uniaxial deformation.
• To develop and validate constitutive equations for predicting PEEK's response.
• To analyze the activation energies associated with different deformation mechanisms.

Main Methods:

• Uniaxial tensile, relaxation, and creep tests were conducted on PEEK.
• Experiments were performed across a broad temperature range (room temperature to 180 °C) and various stress levels.
• Constitutive equations were formulated and their parameters were optimized using experimental data.

Main Results:

• Experimental observations were well-matched by the developed constitutive models.
• Numerical simulations based on the equations showed good agreement with the test data.
• Similar activation energy values were observed for elastoplastic, viscoelastic, and viscoelastoplastic responses above the glass transition temperature.

Conclusions:

• The developed constitutive equations provide an accurate framework for describing PEEK's thermo-mechanical behavior.
• The findings offer insights into the dominant deformation mechanisms of PEEK at elevated temperatures.
• This research contributes to the predictive modeling of advanced polymer performance.