Dynamic Methods for Damage Detection in Structures
October 10, 2005 — October 14, 2005
Coordinator:
- Antonino Morassi (Università di Udine, Udine, Italy)
Within the large class of methods of nondestructive testing, dynamic techniques have received great attention in the engineering communities in last decades. In fact, differently from other conventional diagnostic methods such as visual inspection, radiography and thermal analysis, modal analysis techniques or wave propagation methods offer potential advantages for damage detection in a global scale.
Changes in the vibration response of a structure can be nowadays detected and measured in a rather simple and accurate way. Therefore, the final aim of dynamic methods of damage detection is to interpret the changes induced by a possible damage on the dynamic behavior of a system, using them to predict location and degree of severity of the degradation.
If the aim of the nondestructive methods is clear, the interpretation of the measurements presents intrinsic difficulties that are only partially understood and managed successfully in the field. The main source of difficulty is related to the inverse nature of the diagnostic problem, which is the responsible of typical pathologies, such as non-uniqueness, high non-linearity or non-continuous dependence of the solution on the data. When identification techniques are applied to the study of real structures, additional obstructions arise because of the complexity of structural modelling, the inaccuracy of the analytical models used for the interpretation of the experiments, the measurement errors and the incompleteness of the field data.
Taking these aspects into account, the aim of this course is to present an updated state-of-the-art overview of the general aspects and practical applications of dynamic nondestructive techniques for damage detection in structures, through the interaction of several topics, ranging from modal analysis techniques for damage identification, to application of numerical optimization algorithms and finite element models for parametric identification of damage, to the use of guided ultrasonic waves for inspection in structures. Several experimental applications to real life situations concerning full-scale structures, such as frame and beam structures, buildings and bridges, will be presented and discussed.
The course is aimed at PhD students and postdoctoral researchers working in the area of civil and mechanical engineering or in material science, with interests in practical inverse problems. The proposed course will be also a valuable experience for designer engineers and for engineers working in public administrations.