The exploration of the effect of microstructure on crackling noise systems

A wide variety of physical systems respond to changing external conditions through discrete impulsive events called jerks, typically leading to collective crackling noise behaviour. Statistical distributions of jerky events often exhibit a universal scale-invariant power law, regardless of the specific mechanisms that are responsible for crackling noise processes and microstructural features that affect them. Here, we analyse uniaxial compression loading curves of two different physical systems that exhibit jerky behaviour: a martensitic NiMnGa single crystal and a stack of corrugated fiberboards. The jerky response is attributed to a non-uniform twin boundary motion along the NiMnGa crystal and to a local buckling of individual fiberboard layers. In both cases, our analysis reveals that different variables exhibit different statistical distributions. While the velocity of temporal processes within jerky events exhibits scale invariant distribution, the irreversible displacements induced throughout complete events are distributed around a characteristic value. In the case of NiMnGa, the displacement of a twin boundary is directly related to the length-scale of the internal magneto-mechanical microstructure. Similarly, the displacement of the fiberboard stack corresponds to the thickness of individual board layers. These observations reveal the effect of the internal microstructure on crackling noise systems and demonstrate an analysis approach for uncovering the details of the jerk mechanism. (C) 2015 AIP Publishing LLC.