An Optical Fiber Transducer for Measuring Kinetics of Skull-Brain Interaction in a Surrogate Model of the Human Head Subjected to Blast Overpressure

This paper presents the development and validation of an in-fiber Bragg grating (FBG) transducer for measuring skull-brain kinetics within a surrogate headform used to assess protective headgear during blast exposure. The presented force transducer (6-mm nominal diameter) contains a multi-layered composite superstructure, and demonstrates linearity and repeatability in both impact-response calibrations and blast-loading conditions. Fourier analysis indicates that the presented transducer captures transient kinetics of blast overpressure with an average 0.12% difference in normalized Fourier amplitudes captured by the FBG and validated reference transducer. Time-domain analysis indicates the FBG transducer is repeatable with maximum coefficient of variance for repeated measures at 7.9%, whereas the validated reference transducer coefficient of variance is 9.1% (maximum) based on normalized data. The novel transducer is the first application of FBG technology to measure skull-brain kinetics following loading from a blast, and can be used to evaluate the mechanisms of energy-transfer into the head during blast exposure.