Comparing model-based adaptive LMS filters and a model-free hysteresis loop analysis method for structural health monitoring

• Published in: Mechanical systems and signal processing Vol. 84; pp. 384 - 398
• Main Authors: Zhou, Cong, Chase, J. Geoffrey, Rodgers, Geoffrey W., Xu, Chao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2017
• Subjects: Adaptive filter; Damage identification; Hysteresis loop analysis; Model-based; Reinforced concrete experimental structure; Structural health monitoring; Hysteresis loop analysis; Damage identification; Structural health monitoring; Adaptive filter; Reinforced concrete experimental structure; Model-based
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2016.07.030

The model-free hysteresis loop analysis (HLA) method for structural health monitoring (SHM) has significant advantages over the traditional model-based SHM methods that require a suitable baseline model to represent the actual system response. This paper provides a unique validation against both an experimental reinforced concrete (RC) building and a calibrated numerical model to delineate the capability of the model-free HLA method and the adaptive least mean squares (LMS) model-based method in detecting, localizing and quantifying damage that may not be visible, observable in overall structural response. Results clearly show the model-free HLA method is capable of adapting to changes in how structures transfer load or demand across structural elements over time and multiple events of different size. However, the adaptive LMS model-based method presented an image of greater spread of lesser damage over time and story when the baseline model is not well defined. Finally, the two algorithms are tested over a simpler hysteretic behaviour typical steel structure to quantify the impact of model mismatch between the baseline model used for identification and the actual response. The overall results highlight the need for model-based methods to have an appropriate model that can capture the observed response, in order to yield accurate results, even in small events where the structure remains linear. •The capability necessary to monitor the evolution of structural health over time and multiple events is examined.•It delineates how the model-free method adapts to changes in how structures transfer load across structural elements.•Model-based methods may present an image of greater spread of lesser damage over both DOF and time.•The numerical comparison quantifies the impact of mismatch between the baseline model and the actual response.