Existing strain gages are mostly point sensors that measure local strains from a few discrete locations, while TDR sensor
can interrogate distributed changes along the entire length of the sensor line. The present study investigates feasible
applications of a new technique using TDR as a distributed strain sensor for structural health monitoring. First, a
specially designed TDR sensor laid out on a substrate successfully measured distributed strains and detected a failure
location when the substrate was under an increasing tensile load. Second, a TDR sensor spirally wound around a
cylindrical tank measured a circumferential strain and detected a failure location on the tank surface when the tank was
increasingly pressurized. The developed TDR monitoring technique shows great potential for real-time health
monitoring of various critical structures such as bridge, aircraft, and aerospace applications.