Damage detection of glass fiber reinforced composites using embedded PVA–carbon nanotube (CNT) fibers

In the present work, polyvinyl alcohol carbon nanotube (PVA-CNT) fibers were embedded in glass fiber reinforced plastic composites and used as strain sensors for damage monitoring of the composite. Sensing of the structural integrity of the composite was made by the in-situ measurement of the electrical resistance of the embedded PVA-CNT fiber during the mechanical tests. The multi-functionable materials were tested in tensile progressive damage accumulation (PDA) tests. These tests aimed to seek the electrical response of untreated and pre-stretched PVA-CNT fibers with known level of progressively introduced damage to the composite. The advantages and disadvantages of each PVA-CNT fiber used as a sensor are analyzed; the electrical resistance readings of the PVA-CNT fibers were correlated with known parameters that express the induced damage of the composite.