Plenary Lectures and Keynotes

Markus Sause (University of Augsburg): AE and Industry 5.0: Our contribution to the next big thing

This presentation will explore the relevance of acoustic emission (AE) for Industry 5.0 applications, focusing on the challenges and opportunities arising from the use of AE technology. Therefore we will present the overarching vision of the next industrial revolution - human-centered, resilient and sustainable - and show how this is implemented in our model factory Halle43. We present how we integrate AE technologies to deliver the required data, discuss practical application examples developed with companies, and provide an outlook on future developments. .

Didem Ozevin (University of Illinois) : Acoustic Emission Sensors in the Era of Smart Infrastructure and AI: From Signals to Decisions

The successful implementation of acoustic emission (AE) method relies on sensor design, particularly in terms of frequency selection, sensitivity, size and environmental durability. The increasing complexity of infrastructure systems and extreme conditions, combined with the demand for continuous and permanent monitoring, challenges traditional AE sensors that rely on temporary installation, high-volume data acquisition and inspection-based decision-making. This talk presents a comprehensive perspective on the evolution of AE sensors—from conventional piezoelectric sensors toward emerging architectures that enable selective, scalable, and permanently embedded monitoring. A key focus of this talk is the role of AE sensors in extreme environments, including high-temperature systems, corrosive conditions, radiation exposure, and mechanically harsh settings. These environments impose rigorous requirements on sensor materials, packaging, coupling, and signal stability. Building on these advances, the talk explores the transition from signal-based monitoring to decision-based frameworks. The integration of physics-informed sensor design with artificial intelligence (AI) enables reliable interpretation of AE data under uncertainty. Ultimately, this work highlights a pathway toward intelligent AE sensing systems that transform raw signals into actionable, rapid and real-time decision making.

Jérôme Weiss (Institut des Sciences de la Terre, Grenoble): Probing athermal as well as creep failure of disorded materials from acoustic emission

Brittle or quasi-brittle materials such as rocks or concretes deform and fail from the accumulation and the complex interactions of numerous damage/microcracking events generating transient acoustic waves. Acoustic emission is therefore a privileged non-destructive tool to probe the evolution of internal damage towards final failure in these materials. In this presentation, this will be illustrated for different loading protocols and for a model material with a designable microstructural disorder, concrete.

First, the route towards compressive failure under (rapid) monotonic loading will be discussed. In this case, the role of thermal activation on damage and failure processes can be neglected. These processes are tracked from acoustic emission, in particular from an evolution of the distributions of AE energies and AE durations as approaching final failure. This reveals a divergence of the fracturing correlation length and time towards failure and argues for an interpretation of compressive failure of disordered materials as a critical transition between an intact and a failed state.

In these materials, characterized by a strong intrinsic absorption due to viscous and frictional effects at the microscopic scale, the absorption timescale is small (~100µs) and thus acoustic wave attenuation pronounced. However, paradoxically, this allows to explore, for timescales larger than  the internal temporal structure of the microfracturing events from the temporal evolution of the acoustic intensity of the AE events. This indicates a strong time asymmetry that could be explained, in these quasibrittle materials, by retardation effects induced by enhanced viscoelastic processes within a fracture process zone generated by the damage avalanche as it progresses.

Acoustic emission is also of great interest to probe thermally-activated creep deformation and failure. In this case, the statistics of AE arrival times, i.e. of activation times, are of primary importance to decipher the respective roles of an exhaustion of weak spots by thermal activation in one end, which dominates the dynamics during primary creep, and of stress redistributions in the other hand, which controls the evolution towards tertiary creep and failure.

Overall, this presentation will try to illustrate the key interest of acoustic emission to explore the statistical physics of damage and rupture phenomena in quasi-brittle solids.