A RESISTANCE WIRE TRANSDUCER FOR CIRCUMFERENTIAL STRAIN-MEASUREMENT IN TRIAXIAL TESTS

A resistance wire transducer was designed to measure circumferential d eformation of a partially saturated triaxial specimen. It utilizes for the measurement changing output voltage in a resistance wire transduc er wound around the specimen as it bulges, i.e., increases in circumfe rence. This circumferential change can be converted into lateral defor mation. The proposed transducer is very small, so it is possible to mo unt several of them along the height of a specimen and monitor accurat ely its changing cross sections. The volume of the specimen at any rec ording time can be calculated from the deformed cross section and axia l deformation. The resistance wire transducer is a simple device whose principle provides the potential for a broad spectrum of analogous ap plications.