Acoustic emission during fatigue experiments on first year sea ice

摘要: Abstract Acoustic emission events were measured during the cyclic loading of cantilever beams sea ice. The detected with resonant transducers, bandwidth 20 kHz to 150 kHz, which are predominantly sensitive vertically polarized component Rayleigh surface wave. This confinement surface, along linear geometry beam, make it possible estimate a one dimensional source location only two tranducers. We define an event magnitude and find that this increases as load increases, largest energy release occurring fracture beam. measurement requires high frequency attenuation waves in In absence existing data literature, we our own compare suitably adjusted for compressional waves. sources precursors eventual ice, having highest density at final failure speculate emissions originate either from dislocation breakaway or microcracking associated motion. By measuring slope cumulative magnitude-frequency plot may surmise consistent view system is organising itself into stationary critical state.