secoues

Secoues are brief, localized vibrational events observed in disordered solids under mechanical stress. They typically last from microseconds to a few milliseconds and have a broad spectral content, originating from rapid, localized rearrangements in the material’s microstructure, such as shear transformations in amorphous metals or microcracking in ceramics. The events are spatially confined and often occur in clusters during periods of increasing strain or stress concentration.

Etymology and origin: The term secoues was coined to reflect the shaking-like nature of these events. It draws from the French verb secouer, meaning to shake or tremble, and is used in some materials-science discussions to describe transient energy bursts in solids under load. The concept has been explored in theoretical and experimental studies focusing on avalanche-like dynamics in disordered media.

Detection and characterization: Secoues are detected with high-speed measurement techniques such as laser Doppler vibrometry, fast ultrasound, and acoustic-emission sensors. Key parameters include duration, energy, peak frequency, spectral bandwidth, and spatial localization. Analysis often seeks to distinguish secoues from background noise and other, longer-lived vibrational phenomena.

Occurrence and contexts: Reported in a range of disordered solids, including metallic glasses, polymer glasses, and ceramic composites, secoues typically arise under rapid loading, cyclic loading, or thermal cycling, especially near yield or damage onset. They are of interest as potential precursors to macroscopic failure and as indicators of microstructural instability.

Significance and applications: Understanding secoues can improve models of failure in amorphous materials, inform non-destructive evaluation methods, and contribute to a broader understanding of avalanche processes in disordered systems. Further study is needed to establish consistent detection criteria and material-specific behavior.

See also: Acoustic emission, microcracking, avalanche dynamics in solids.