Acoustic Emissions in Fracturing Sea Ice Plate Simulated by Particle System

Abstract

In-plane dynamic fracture jumps and acoustic emissions in sea ice floes of different sizes are simulated by the particle system. Fracture patterns and time sequences similar to those observed in experiments are achieved. For the given spatial location of hydrophone, the acoustic signals from crack jumps in ice are calculated in the frequency domain by a modified Farmer and Xie's acoustic model for ice plate floating in shallow sea. The acoustic pressure-time histories are synthesized by the Fourier inverse transform. The calculated acoustic signals resemble the recorded signals. Their overall character is found to depend on the plate size. This is a size effect that is manifested in the calculated root-mean-square history of the acoustic pressure at hydrophone. Differences among the acoustic records for different fracture lengths are found. They offer the possibility of making inferences on the fracture characteristics of sea ice from the acoustic records.