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Guided waves for monitoring of plate structures with linear cracks of variable length

Zima B., Rucka M.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 3

387--396

EN

Damage occurring at the work of plate structures may grow to a considerable size. The joint action – the detection of a defect at the earliest possible stage, the monitoring of its growth and the determination of its critical size in the context of structural reliability allows optimizing the cost of the maintenance and repair of structural elements. Thus the development of monitoring systems for permanent observation of fault evolution is of great importance among civil, mechanical and aerospace engineering communities. This paper focuses on a diagnostic system dedicated for plate structures with a variable length linear crack using the guided wave-based technique and a novel ellipse-based binary damage imaging algorithm. The emphasis is put on the relationship between the configuration of embedded piezoelectric transducers and the extent of a defect possible to identify. Numerical and experimental results show that the proposed diagnostic system has a great potential for the implementation in monitoring systems dedicated for the evaluation of damage growth.

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Testing of composite panels used as components of a freight wagon by thermovision

Wróbel A., Płaczek M., Buchacz A.

Acta Mechanica et Automatica

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2016

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Vol. 10, no. 1

17--21

EN

In this paper research methods for detection of laminate panels damage were presented. The most common damage is: matrix cracking laminate interlayer damage to joints, connecting cracks, delamination and fiber breakage. The tested laminates will be used as assemblies and sub-assemblies of freight wagon. Other methods of modeling of machines by means of transducers are shown in Płaczek (2012, 2015) and Białas (2010). As part of the project authors were collaborated with specialists from other research centers and scientific research (Bocian and Kulisiewicz, 2013). As a part of future work the places where we will be able to replace the standard materials by parts made of laminate will be shown. Layered composites despite many advantages have also disadvantages. From last mentioned it is a relatively low resistance to transverse impact. When the laminate is used as a decorative element, its small damage is not a problem. The problems start when the composite satisfies more responsible tasks such as: is a part of the technical means for example of a railway wagon. Aspect of continuous monitoring of the technical state of the laminate is very important. Current technology provides numerous opportunities for non-destructive methods of technical inspections. In this paper method for testing of large areas, completely non-contact, based on the methods of thermography, was presented. It consists heating by using the composite tubes and examining it through a thermal imaging camera. Length of heating, and consequently the temperature to which the laminate is heated mostly were chosen experimentally. During the measurements, the camera measures the intensity of radiation, not temperature. Received thermogram is not always a precise representation of the actual temperature, because the camera does not reach only the radiation from tested object, but also reaches the radiation coming from the environment and reflected objects etc. As part of the research authors also we undertook other work related to Mechanical Engineering (Wróbel et al., 2008, 2010, 2012, 2013, 2015; Płaczek et al., 2014). Cooperation with other national and European centers has contributed to many publications of authors for example Tuma et al. (2013, 2014) and Jamroziak and Kosobudzki (2014).

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Obrazowanie obiektów ukrytych pod powierzchnią

Janczulewicz A., Bujnowski A., Wtorek J.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 10

111-119

PL

W pracy przedstawiono wyniki badań symulacyjnych uzyskanych za pomocą rekonstrukcji elektryczno-magnetycznej. Przedstawiono konstrukcję matrycy czujników (elektrod i cewek) charakteryzująca. się przestrzennym rozkładem czułości umożliwiającym detekcje obiektów ukrytych tuż pod powierzchnią. Pokazano, że nawet w przypadkach dużej niejednorodności i w obecności szumów pomiarowych jest możliwe wykrycie anomalii w postaci znacznego zaburzenia przewodności.

EN

Simulation results of electromagnetic reconstructions are presented in the paper. A multi-sensor array containing electrodes and coils have been proposed. It is characterized by a spatial sensitivity distribution which allows to detect of an object hidden under the surface. It is shown that it is possible to detect of the hidden object even in the case of large inhomogeneity of region conductivity and measurement.

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Rejestracja obrazów i wizualizacja przestrzenna tkanek na przykładzie konfliktu naczyniowo-nerwowego

Skibińska A., Drapikowski P., Sosnowski P.

Studia z Automatyki i Informatyki

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2006

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T. 31

31-42

PL

Równoczesne wykorzystanie informacji z różnych metod obrazowania (CT, MRI, różne protokoły MRI) daje możliwość dokładniejszego diagnozowania oraz tworzenia modeli przestrzennych tkanek wykorzystywanych następnie w symulacji przedoperacyjnej. W ten sposób uzyskuje się pełniejszy obraz obszaru anatomicznego, który ma być przedmiotem interwencji chirurgicznej. W pracy przedstawiono metody segmentacji i rejestracji danych wolumetrycznych zarejestrowanych podczas badania MRI (różne protokoły obrazowania). Wykonano modele przestrzenne naczyń i nerwów w obrębie czaszki dla siedmiu pacjentów na przykładzie schorzenia zwanego konfliktem naczyniowo-nerwowym. W przygotowaniu przedoperacyjnym jest niezmiernie istotna precyzyjna lokalizacja wzajemnego położenia naczyń i nerwów, co ma decydujący wpływ na sposób przeprowadzenia operacji.

EN

3D visualization is one of the major directions of evolution of the present-day medical imaging. The main advantage of this method is the capability of watching anatomical structures in every way, independently of the slab plane. Just as an object in the hands. Construction of 3D models of pathological areas helps in medical treatment, such as surgery planning and navigation. One of the terms related to the 3D visualization is image registration. Especially mapping between two series of medical images (monomodal or multimodal) and mapping of medical equipment coordinates into anatomical structures space. This work consist image processing application in visualization of neurovascular compression syndromes (NVC). NVC is a group of illnesses caused by the compression of cranial nerve by vessel. More precisely it includes a survey of image registration methods and its major problems and application of chosen method on the real MRI data. The algorithm obtained was tested on MRI data of seven patients from the HCP hospital in Poznań. The results already obtained were a good sign to continue this work.