Transducers for impact force and mechanical impedance based on strain measurement

Abstract: Transducers for impact force and mechanical point impedance are studied. In both cases the transducers are based on resistive strain measurement. Two prototypes of impact force transducers based on different concepts of mean strain measurement are developed and tested. The results are satisfactory and show that the suggested concepts are suitable. The transducer for mechanical point impedance is based on strain measurement at two points along a linearly elastic rod which acts as a wave guide for longitudinal waves. One end of the rod is in contact with the object while the other end is excited by impact. Tests are conducted on attached cylindrical rods as well as on unattached beams. The performance of the transducer is generally good. Impedances measured on the unattached beams are generally in good agreement with corresponding results obtained with a conventional impedance head.