Study of passive deck-flaps flutter control system on full bridge model. I: Theory.

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Full bridge model study of a passive aerodynamic flutter suppression system

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Diagnostyka zginanej płyty betonowej z zastosowaniem fal ultradźwiękowych modulowanych drganiami niskich częstotliwości

The paper presents the experimental study on the inter-modulation method for the diagnostics of concrete elements. The tests were conducted on a concrete plate subjected to ultrasonic waves and low frequency vibrations. The nonlinear acoustic effects, recorded in the experiments, made it possible to detect the presence of damaged zones. Further studies are necessary to establish the relation between the sidebanes of frequency spectra and the size of the damaged zone.Artykuł poświęcony jest eksperymentalnej weryfikacji możliwości zastosowania modulacji diagnostycznej fali ultradźwiękowej drganiami niskich częstotliwości. Metoda jest zastosowana do wykrywania stref uszkodzenia płyty betonowej i bazuje na efektach nieliniowych wynikających z otwierania się rys. Uzyskane wyniki pozwalają na sformułowanie wniosku, że badana metoda umożliwia wykrywanie stref zarysowanych wraz z oszacowaniem ich rozmiaru. Efektywność proponowanej metody jest lepsza niż standardowe badanie z zastosowaniem betonoskopu lub metody młoteczkowej (impact echo

VIBRATION DIAGNOSTICS OF FOOTBRIDGE WITH USE OF ROTATION SENSOR

The benefits of the additional measurement of rotational degrees of free-dom on the performance of the vibration diagnosis of bridges are studied in this paper. The common vibrational diagnostics that uses translational degrees of freedom is extended by measurements of rotations. The study is curried out on a footbridge and the presence of damage as well as its location and size is determined with use of FEM updating procedure. The results showed that rotational degrees of freedom significantly improve the effectiveness of the vibrational method

Badania wiaduktu nad torami kolejowymi przy PGE Arena w Gdańsku podczas jego realizacji

The paper presents the in situ tests carried out during the erection of viaduct WD-1 which is a part of Trasa Slowackiego in Gdansk. Due to the unique and innovative form of the arch girder which is created by twisted pipes, the structural monitoring tests were conducted in the DIM Laboratory in the Department of Structural Mechanics and Bridge Structures at Gdansk University of Technology. The scope of tests included arch abutment measurement system, periodic control of forces in hangers during tensioning process and finally load testing.W pracy przedstawiono badania wiaduktu WD-1 realizowanego w ramach Trasy Słowackiego w Gdańsku. Ze względu na nietypową, innowacyjną formę splecionego łukowego dźwigara nośnego Laboratorium DIM (Diagnostyki, Identyfikacji i Monitoringu) działającemu przy Katedrze Mechaniki Budowli i Mostów Politechniki Gdańskiej zlecono opracowanie i realizację badań kontrolnych. Zakresem badań objęto monitoring wezgłowii łuków i sił w wieszakach linowych podczas ich naciągania oraz próbne obciążenie obiektu

Nanomaterials by severe plastic deformation: review of historical developments and recent advances

International audienceSevere plastic deformation (SPD) is effective in producing bulk ultrafine-grained and nanostructured materials with large densities of lattice defects. This field, also known as NanoSPD, experienced a significant progress within the past two decades. Beside classic SPD methods such as high-pressure torsion, equal-channel angular pressing, accumulative roll-bonding, twist extrusion, and multi-directional forging, various continuous techniques were introduced to produce upscaled samples. Moreover, numerous alloys, glasses, semiconductors, ceramics, polymers, and their composites were processed. The SPD methods were used to synthesize new materials or to stabilize metastable phases with advanced mechanical and functional properties. High strength combined with high ductility, low/room-temperature superplasticity, creep resistance, hydrogen storage, photocatalytic hydrogen production, photocatalytic CO2 conversion, superconductivity, thermoelectric performance, radiation resistance, corrosion resistance, and biocompatibility are some highlighted properties of SPD-processed materials. This article reviews recent advances in the NanoSPD field and provides a brief history regarding its progress from the ancient times to modernity