The mechanical performance of pultruded composite rods with embedded fiber-optic sensors

Fiber-optic strain sensors are successfully embedded in glass- and carbon-f iber-reinforced polymer (GFRP and CFRP) tendons during pultrusion. The stud y of the performance of the embedded Fabry-Perot fiber-optic sensors under conditions of static and dynamic lending when exposed to both low and high temperature extremes, is presented. The experiments entailed subjecting the GFRP and CFRP tendons to sinusoidal and trapezoidal load waveforms of abou t 11 kN magnitude inside a temperature chamber. The temperature in the cham ber was varied from -40 to 60 degrees C in increments of 20 degrees C. The strain output from the embedded sensors was compared to that from externall y mounted extensometers as well as to theoretical strain values. It was det ermined that the performance of the Fabry-Perot sensors was not affected by ambient temperatures falling within the range of -40 to + 60 degrees C and the sensor readings conformed very well with the corresponding extensomete r and theoretical readings. (C) 2000 Elsevier Science Ltd. All rights reser ved.