Stress and temperature self-sensing fibres

The Raman response of aramid fibers is examined as a function of the applied stress and temperature. Noticeable wavenumber shifts are recorded for the 1611 and 1648 cm−1 Raman bands with increasing stress. In contrast, only the 1611 cm−1 band is affected by temperature within the −50 to 200 °C range. The existence of two adjacent vibrational modes sensitive to stress with only one of the two being temperature dependent, allows the development of a simultaneous stress and temperature spectroscopic sensor. The applicability of this sensor is evaluated on an epoxy resin – aramid fiber composite activated by a shape-memory-alloy actuator.