A Non-destructive Approach for Damage Localization in Civil or Mechanical Structures Without Reference Model

The assessment of structural integrity and damage localization using non-destructive monitoring methods has been an area of significant research interest for decades, and it remains highly relevant, especially in light of the increasing exposure of structures to catastrophic events. The challenge becomes even more complex when the goal is to detect and localize damage solely based on sensor data from a damaged structure, without any reference to its undamaged state. One method that has garnered substantial attention in recent years is based on analyzing the curvature of mode shapes, which relies on the relationship between curvature (i.e., the second derivative) and localized changes in structural stiffness. In this work, a new reference-free method is proposed, introducing a novel damage indicator that leverages only the first derivative, combined with appropriate filters, to localize damage on the structure, using data exclusively from the damaged state. Promising results have been achieved by applying this approach to a simulated real-world structure, using accelerometers placed throughout the structure. However, the need for a sufficient number of data points distributed across the structure can sometimes complicate data acquisition. This challenge can be addressed by implementing a multi-step acquisition process, where a limited number of sensors are moved along the structure during the entire measurement process to gather data from the entire structure. The damage detection results obtained through the described method with the use of this approach demonstrate its effectiveness, paving the way for applying this type of damage detection to real-world structures.