A Review of Vibration-based Structural Health Monitoring with Special Emphasis on Composite Materials

D. Montalvao
2006 The Shock and vibration digest  
Structural health monitoring and damage detection techniques are tools of great importance namely in the offshore, civil, mechanical and aeronautical engineering communities, either due to safety reasons or to the economical benefits it may bring. The need for detecting damage in complex structures has led to the development of a vast amount of techniques, in particular those based upon structural vibration analysis. In the present article, some of the latest advances in Structural Health
more » ... ring and Damage Detection have been covered, with an emphasis on composite structures, given the fact that this kind of materials have currently a wide range of engineering applications. FOREWORD It should be noted that this review is not intended to be a general, all-encompassing review about structural health monitoring (SHM); it was planned as the starting point for a study focusing on damage detection, localization and assessment on certain kind of structures. Thus, the line of thought behind the search and the structure of this review is a result of objectives beyond the scope of the paper itself. Nevertheless, it was considered that, once the above was understood, an updated synopsis such as this could also be useful for other researchers in the same field. According to Doebling et al. (1996**) , ideally, a robust damage detection scheme should be able to identify damage at a very early stage, locate the damage within the sensor resolution being used, provide some estimate for the damage extension or severity and to predict the remaining useful life of the structural component where damage has been identified. The method should also be well suited to automation, and should be independent from human judgment and ability. Betti (2005) points out that no single approach is appropriate for all situations, making the following basic distinctions between each approach: linear vs non-linear, output only vs input/output, on-line vs -3 -off-line, time domain vs frequency domain, parametric vs non-parametric and time varying vs timeinvariant. Operational and environmental conditions, such as temperature, humidity, loads and boundary conditions should also be addressed, since in many cases they can 'hide' changes strictly caused by damage. For example, Farrar et al. (1994* , **), having done several measurements on the I-40 bridge over the Rio Grande in Albuquerque in the state of New Mexico in the USA, observed that temperature plays a major role in the dynamic properties of the bridge. They introduced four different levels of damage by gradually cutting one of the bridge girders, corresponding to a loss of stiffness. However, instead of what would be expectable, they noticed an increase in the fundamental frequency for the first two damage cases, concluding that such results were mainly due to temperature changes and temperature gradients in the bridge. Many other researchers, such as Woon
doi:10.1177/0583102406065898 fatcat:cpo5laltkrdyngvekhxholoiaq