Damage detection on output-only monitoring of dynamic curvature in composite decks

Domaneschi, M.,Sigurdardottir, D.,Glisic, B. Techno-Press 2017 Structural monitoring and maintenance Vol.4 No.1

Installation of sensors networks for continuous in-service monitoring of structures and their efficiency conditions is a current research trend of paramount interest. On-line monitoring systems could be strategically useful for road infrastructures, which are expected to perform efficiently and be self-diagnostic, also in emergency scenarios. This work researches damage detection in composite concrete-steel structures that are typical for highway overpasses and bridges. The techniques herein proposed assume that typical damage in the deck occurs in form of delamination and cracking, and that it affects the peak power spectral density of dynamic curvature. The investigation is performed by combining results of measurements collected by long-gauge fiber optic strain sensors installed on monitored structure and a statistic approach. A finite element model has been also prepared and validated for deepening peculiar aspects of the investigation and the availability of the method. The proposed method for real time applications is able to detect a documented unusual behavior (e.g., damage or deterioration) through long-gauge fiber optic strain sensors measurements and a probabilistic study of the dynamic curvature power spectral density.

Vibration based damage localization using MEMS on a suspension bridge model

Domaneschi, Marco,Limongelli, Maria Pina,Martinelli, Luca Techno-Press 2013 Smart Structures and Systems, An International Jou Vol.12 No.6

In this paper the application of the Interpolation Damage Detection Method to the numerical model of a suspension bridge instrumented with a network of Micro-Electro-Mechanical System sensors is presented. The method, which, in its present formulation, belongs to Level II damage identification method, can identify the presence and the location of damage from responses recorded on the structure before and after a seismic damaging event. The application of the method does not require knowledge of the modal properties of the structure nor a numerical model of it. Emphasis is placed herein on the influence of recorded signals noise on the reliability of the results given by the Interpolation Damage Detection Method. The response of a suspension bridge to seismic excitation is computed from a numerical model and artificially corrupted with random noise characteristic of two families of Micro-Electro-Mechanical System accelerometers. The reliability of the results is checked for different damage scenarios.

Refined optimal passive control of buffeting-induced wind loading of a suspension bridge

Domaneschi, M.,Martinelli, L. Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.18 No.1

Modern design of long suspension bridges must satisfy at the same time spanning very long distances and limiting their response against several external loads, even if of high intensity. Structural Control, with the solutions it provides, can offer a reliable contribution to limit internal forces and deformations in structural elements when extreme events occur. This positive aspect is very interesting when the dimensions of the structure are large. Herein, an updated numerical model of an existing suspension bridge is developed in a commercial finite element work frame, starting from original data. This model is used to reevaluate an optimization procedure for a passive control strategy, already proven effective with a simplified model of the buffeting wind forces. Such optimization procedure, previously implemented with a quasi-steady model of the buffeting excitation, is here reevaluated adopting a more refined version of the wind-structure interaction forces in which wind actions are applied on the towers and the cables considering drag forces only. For the deck a more refined formulation, based on the use of indicial functions, is adopted to reflect coupling with the bridge orientation and motion. It is shown that there is no variation of the previously identified optimal passive configuration.

Refined optimal passive control of buffeting-induced wind loading of a suspension bridge

M. Domaneschi,L. Martinelli 한국풍공학회 2014 한국풍공학회지 Vol.18 No.1

Modern design of long suspension bridges must satisfy at the same time spanning very longdistances and limiting their response against several external loads, even if of high intensity. StructuralControl, with the solutions it provides, can offer a reliable contribution to limit internal forces anddeformations in structural elements when extreme events occur. This positive aspect is very interesting whenthe dimensions of the structure are large. Herein, an updated numerical model of an existing suspensionbridge is developed in a commercial finite element work frame, starting from original data. This model isused to reevaluate an optimization procedure for a passive control strategy, already proven effective with asimplified model of the buffeting wind forces. Such optimization procedure, previously implemented with aquasi-steady model of the buffeting excitation, is here reevaluated adopting a more refined version of thewind-structure interaction forces in which wind actions are applied on the towers and the cables consideringdrag forces only. For the deck a more refined formulation, based on the use of indicial functions, is adoptedto reflect coupling with the bridge orientation and motion. It is shown that there is no variation of thepreviously identified optimal passive configuration.

Vibration based damage localization using MEMS on a suspension bridge model

Marco Domaneschi,Maria Pina Limongelli,Luca Martinelli 국제구조공학회 2013 Smart Structures and Systems, An International Jou Vol.12 No.6

In this paper the application of the Interpolation Damage Detection Method to the numerical model of a suspension bridge instrumented with a network of Micro-Electro-Mechanical System sensors is presented. The method, which, in its present formulation, belongs to Level II damage identification method, can identify the presence and the location of damage from responses recorded on the structure before and after a seismic damaging event. The application of the method does not require knowledge of the modal properties of the structure nor a numerical model of it. Emphasis is placed herein on the influence of recorded signals noise on the reliability of the results given by the Interpolation Damage Detection Method. The response of a suspension bridge to seismic excitation is computed from a numerical model and artificially corrupted with random noise characteristic of two families of Micro-Electro-Mechanical System accelerometers. The reliability of the results is checked for different damage scenarios.

Existing concrete dams: loads definition and finite element models validation

Colombo, Martina,Domaneschi, Marco,Ghisi, Aldo Techno-Press 2016 Structural monitoring and maintenance Vol.3 No.2

We present a methodology to validate with monitoring data finite element models of existing concrete dams: numerical analyses are performed to assess the structural response under the effects of seasonal loading conditions, represented by hydrostatic pressure on the upstream-downstream dam surfaces and thermal variations as recorded by a thermometers network. We show that the stiffness effect of the rock foundation and the surface degradation of concrete due to aging are crucial aspects to be accounted for a correct interpretation of the real behavior. This work summarizes some general procedures developed by this research group at Politecnico di Milano on traditional static monitoring systems and two significant case studies: a buttress gravity and an arch-gravity dam.

Radiographic analysis of the management of tooth extractions in head and neck-irradiated patients: a case series

Oliveira Samanta V.,Vellei Renata S.,Heguedusch Daniele,Domaneschi Carina,Costa Claudio,de Barros Gallo Camila 대한영상치의학회 2021 Imaging Science in Dentistry Vol.51 No.3

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

Radiographic analysis of the management of tooth extractions in head and neck-irradiated patients: a case series

Oliveira, Samanta V.,Vellei, Renata S.,Heguedusch, Daniele,Domaneschi, Carina,Costa, Claudio,Gallo, Camila de Barros Korean Academy of Oral and Maxillofacial Radiology 2021 Imaging Science in Dentistry Vol.51 No.-

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.