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Kolsky Bar Experiment For High-Rate Large Deformations Of Polycarbonate, Jason Gerald Vogeler
Kolsky Bar Experiment For High-Rate Large Deformations Of Polycarbonate, Jason Gerald Vogeler
Department of Engineering Mechanics: Dissertations, Theses, and Student Research
Polycarbonate (PC) is a tough, transparent engineering thermoplastic. Its impact strength and ability undergo large plastic deformations without shatter make PC an ideal protective material for impact-resilient eyewear, aircraft windows and transparent armor. A good understanding of the response of this material to large deformations at high strain rates is critical for its utilization in these applications. To this end, a striker-less Kolsky bar device is employed in this work for the needed material characterization. The apparatus allow impulsive torsion and/or compression loadings with pulse durations sufficiently long for the plastic flow behavior to develop fully. Three new testing techniques …
Anomalous Loss Of Toughness Of Work Toughened Polycarbonate, Shawn E. Meagher
Anomalous Loss Of Toughness Of Work Toughened Polycarbonate, Shawn E. Meagher
Department of Engineering Mechanics: Dissertations, Theses, and Student Research
Glassy polymers such as polycarbonate (PC) can be toughened through compressive plastic deformation. The increase in toughness is substantial, showing as much as a fifteen fold increase in the amount of dissipated energy during failure for samples compressed to 50% plastic strain. This toughness increase can be reversed through thermal aging at temperatures below the glass transition temperature (Tg = 147°C).
The combined effect of plastic compression and thermal aging has been studied using Charpy, Single Edge Notch Bending (SENB), and Compact Tension (CT) tests. The tests mapped the response of samples cut along different orientations relative to the …