Health Monitoring

                In subject area: Engineering
                
                Health monitoring is a nondestructive technique that allows the
                
                integrity of systems or structures to be actively monitored during
                
                operation and/or throughout their lives to prevent failure and reduce
                
                maintenance costs.
                
                From: Integrated System Health Management, 2017

Health Monitoring Of Composite Structures

Vladan Koncar, in Smart Textiles for In Situ Monitoring of Composites, 2019

Health monitoring definitions

As stated in Section 2.6.6, health monitoring is defined as the tracking of any aspect of a structure's health by reliably measured data and analytical simulations in conjunction with heuristic experience, so that the current and expected future performance of the composite part for at least the most critical limit events, can be described in a proactive manner. The single most important distinction of health monitoring from a typical in-depth composite part evaluation and testing practice is the minimum standards that are required for analytical modeling for trustworthy computer simulations, and how the measurements, loads, and tests are designed and implemented in conjunction with the analytical simulations. The process of implementing a damage detection and characterization strategy for engineering structures is referred to as Structural Health Monitoring (SHM). Here, damage is defined as changes of the material and/or geometric properties of a structural system, including changes to the boundary conditions and system connectivity, which adversely affect the system's performance. The SHM process involves the observation of a system over time using periodically sampled dynamic response measurements from an array of sensors, the extraction of damage-sensitive features from these measurements, and their statistical analysis to determine the current state of system health. For long-term SHM, the output of the process is periodically updated with information regarding the ability of the structure to perform its intended function in light of the inevitable aging and degradation resulting from operational environments. Continuous health monitoring of materials would result in improved durability and safety of structures. The basic idea is to build a system similar to the human nervous system, with a network of sensors placed in critical areas where structural integrity must be maintained. Mathematical algorithms based on a “neural network” then can be trained to recognize patterns of electrical signals that represent damage, such as fiber strains or breakage and matrix cracks. In broadest terms, therefore, SHM comprises a distributed network of sensors that are deployed as integral parts of a structure and that are capable of collecting and sending information to an interrogator or electronic monitoring device.