Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Jakubowski, K. J." wg kryterium: Wszystkie pola


Wyświetlanie 1-2 z 2
Tytuł:
Code calculations for local stability of shaft guides
Autorzy:
Fiołek, P.
Jakubowski, J.
Tomczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/178575.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
shaft steelwork
corrosion loss
local buckling
steel profile
FEM simulation
Opis:
Steel structures for a conveyance guiding system are subjected to prolonged, intense corrosion during their operation leading to a considerable loss of material and structure capacity reduction. Shaft guides are made of closed profiles welded from hotrolled channel sections. These profiles are categorized as class 1 cross-sections according to Eurocode 3, which means that they are resistant to local instability upon bending [1]. With an increase in the corrosion loss of the guides, the inertia moment of the crosssection is reduced. The resistance of profiles to local buckling is also reduced. However, calculations for local stability in guides upon bending are not required by the local Polish regulations on the operation of conveyance in shafts [2]. The question is whether this constitutes a shortcoming and risk for safe operation. Calculations according to steel construction standards [1] supported by numerical simulation were used to evaluate shaft steelwork guides resistance to buckling and their sensitivity to corrosion loss. It was shown that the guides of corrosion loss of 52-63%, depending on profile size, are prone to local buckling.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 3; 11-16
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method for assessment of changes in the width of cracks in cement composites with use of computer image processing and analysis
Autorzy:
Tomczak, K.
Jakubowski, J.
Fiołek, P.
Powiązania:
https://bibliotekanauki.pl/articles/178219.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cracks in concrete
crack width measurement
image processing
self-healing
Opis:
Crack width measurement is an important element of research on the progress of self-healing cement composites. Due to the nature of this research, the method of measuring the width of cracks and their changes over time must meet specific requirements. The article presents a novel method of measuring crack width based on images from a scanner with an optical resolution of 6400 dpi, subject to initial image processing in the ImageJ development environment and further processing and analysis of results. After registering a series of images of the cracks at different times using SIFT conversion (Scale-Invariant Feature Transform), a dense network of line segments is created in all images, intersecting the cracks perpendicular to the local axes. Along these line segments, brightness profiles are extracted, which are the basis for determination of crack width. The distribution and rotation of the line of intersection in a regular layout, automation of transformations, management of images and profiles of brightness, and data analysis to determine the width of cracks and their changes over time are made automatically by own code in the ImageJ and VBA environment. The article describes the method, tests on its properties, sources of measurement uncertainty. It also presents an example of application of the method in research on autogenous self-healing of concrete, specifically the ability to reduce a sample crack width and its full closure within 28 days of the self-healing process.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 2; 73-80
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies