Low Velocity Impact of Bistable Laminated CFRP Composites
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Laminated carbon fiber reinforced polymer (CFRP) composites have gained popularity in engineering applications due to their lightweight and strong in-plane mechanical properties. This material, however, performs poorly with respect to out-of-plane impact resistance. The objective of this research was to investigate the effect of bistability on the low velocity impact resistance of laminated CFRP composites. Bistable composites have the ability to alternate between two different geometric equilibria through external loading, and when unloaded, do not require external forces to maintain either geometry. Laminated CFRP composite specimens of bistable, flat symmetric, and curved symmetric configurations were subjected to low velocity impacts of 20 J. The acceleration and force of each impact was recorded using an accelerometer and a load cell mounted on the impactor. The sensor data was used to analyze the dynamic response and calculate the energy absorption of each impact. Post-impact crack length measurements and damage characterization were used to conduct a damage resistance analysis. The effects of geometry, stacking sequence, and bistability of the impacted specimens were determined. The results showed that bistability improves the low velocity impact damage resistance of laminated CFRP composites through increased energy absorption and specimen kinetic energy.
KeywordsCarbon fiber Low velocity impact Bistability Impact behavior
The authors thank Dr. Brandon Ross for access to the high speed camera utilized in this research and Michael Stoner for assisting in the usage of the camera.
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