Wyniki wyszukiwania - Biblioteka Nauki

1

Błędy wykonawcze i niewłaściwe użytkowanie przyczyną uszkodzeń w budynku mieszkalnym

100%

Nowak K. , Dębowski J.

Czasopismo Techniczne. Budownictwo

|

2012

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tom R. 109, z. 2-B

297--304

PL

W niniejszym artykule przedstawiono uszkodzenia elementów ściennych i posadzkowych zaobserwowane w lokalu mieszkalnym, który mimo iż został właściwie zaprojektowany, to na wskutek wadliwego wykonawstwa oraz niewłaściwego użytkowania obiektu nie spełniał standardów użytkowych. W artykule wykorzystano badania in situ kamerą termowizyjną oraz analizy symulacyjne.

EN

This paper presents damage to wall and floor elements observed in an apartment which – in spite of having been designed properly – did not satisfy the standards as a result of faulty contracting and inappropriate exploitation. The article uses in situ research by means of a thermovision camera as well as simulation analyses.

2

The concept of using a weighted amplitude to determine the fatigue life of load stress blocks

80%

Obrał J.

Journal of Theoretical and Applied Mechanics

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2021

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tom Vol. 59 nr 3

515--518

EN

This work shows the model for determining the fatigue life of block loads. The proposed model is a kinematic model that can be used using a linear fatigue characteristic, i.e. in the range of a large number of cycles. The model has been developed on the basis of the previous hypotheses of cumulation of damage by Palmgren-Miner using a weighted amplitude of m-degree. The final version proposes calculation of the variable amplitude of the average based on these two models.

3

Influence of the Fatigue Load Level and the Hole Diameter on the Laminate Structure’s Fatigue Performance

80%

Zalewska M.

Fatigue of Aircraft Structures

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2018

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tom Iss. 10

21--30

EN

Damage tolerance of composite aircraft structure is one of the main areas of research, important when a new product is being developed. There are a number of variables, such as damage characteristics (dent depth, delamination area) and loading parameters (load type, amplitude of cyclic loading, load sequence) that need to be investigated experimentally [1]. These tests of composite materials are usually performed at an element level and are carried out in order to validate the analytical model, developed to predict the full-scale component’s behaviour. The paper presents the results of compression testing of the [36/55/9] carbon fibre/epoxy laminate, manufactured with the Automated Fibre Placement technology (AFP) and subjected to static and fatigue loads. The laminate compression loading mode was achieved through sandwich 4-point flexure. At the stage of fatigue testing, two parameters were investigated: the damage size, simulated by the hole diameter and the fatigue load level. Based on the test results, the laminate fatigue load limit equal to 75% of the OHC failure load was evaluated. By collating the static and fatigue tests results, the damage tolerance characteristic of the considered laminate was created.

4

Idea przeobrażenia świata w środowisku rosyjskiej inteligencji

80%

Kaźmierczyk Z.

Acta Neophilologica

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2019

|

tom XXI/2

77-90

EN

This paper displays the birth of the Russian intelligentsia and demonstrates the differences between educated people and members of the intelligentsia. It proves that each member of the intelligentsia is educated, while not every educated person is a member of the intelligentsia. Such a person needs to be fanatically devoted to the idea of the emancipation of the people, which is followed by atheists. The paper distinguishes the Russian intelligentsia and the Polish intelligentsia. It discovers the destructiveness of the intelligentsia based on the Gnostic-Manichaean foundation. It emphasizes the anti-worldness of the secularization of religious beliefs and ideas which are averse to the world as such. It proves that the Russian idea of the world transformation is motivated by destructive desires: hatred towards life, towards existence in bodily and physical mortal life. The author of the paper proves that the response to the destructive potential of the idea of the absolute world transformation triggered the beginnings of the Russian religious rebirth – the return to the metahistorical dimension of the Russian idea.

5

Acoustic Emission Response and Damage Process for Q235 Steel in an in Situ Tensile Test

80%

Zhang Y. , Li Y. , Lai H. S. , Bai C. , Liu K. L.

Archives of Acoustics

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2019

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tom Vol. 44, No. 4

807--813

EN

Q235 steel is widely used in engineering and construction. Therefore, it is important to identify the damage mechanism and the acoustic emission (AE) response of the material to ensure the safety of structures. In this study, an AE monitor system and an in situ tensile test with an optical microscope were used to investigate the AE response and insight into the damage process of Q235 steel. The surface of the specimen was polished and etched before the test in order to improve the quality of micrographs. Two kinds of AE responses, namely a burst and a continuous signal, were recorded by the AE monitor system during the test. Based on the in situ test, it was observed that the damage of Q235 steel was induced by the crystal slip and the inclusion fracture. Since the crystal slip was an ongoing process, continuous AE signals were produced, while burst AE signals were possibly produced by the inclusion fracture which occurred suddenly with released higher energy. In addition, a great number of AE signals with high amplitude were observed during the yielding stage and then the number and amplitude decreased.

6

Avalanche statistics in transfer load models of evolving damage

80%

Derda T.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

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2011

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tom Vol. 10, nr 1

21-31

EN

The damage evolution occurring in a set of elements in the nodes of the supporting one- and two-dimensional lattices is analysed within the stochastic Fibre Bundle Model approach. The element-strength-thresholds are drawn from a given probability distribution and the set of elements is subjected to an external load that is increased quasi-statically. If an element fails, its load has to be transferred to the other intact elements. We compare avalanche statistics i.e. the number of damaged elements for three different load transfer protocols, namely the global, local and recently introduced so-called Voronoi load transfer rule. Our example system is an array of nanopillars.

7

A Finite Element Analysis of the Superplastic Blow-Forming in an Awl-shaped Die with Titanium Alloy

80%

Chen D.-C. , Wang H.-N.

Computer Methods in Materials Science

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2008

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tom Vol. 8, No. 3

130-137

EN

This study employs commercial DEFORM™ 3D finite element analysis software to simulate the superplastic blow-forming of Ti-6Al-4V titanium alloy sheet into triangular, square and conical awl-shaped dies. In performing the simula-tions, the die model is constructed using 3D solid elements and the titanium sheet is assumed to be a rigid-plastic material with homogeneous and isotropic properties. The simulations focus specifically on the respective effects of the shear friction, the sheet thickness, and the damage value criterion on the distributions of the effective stress, effective strain, damage, and deformation velocity within the blow-formed products. Overall, the simulation results confirm the suitability of DEFORM™ 3D software for modeling the superplastic blow-forming of titanium alloy sheets into awl-shaped dies with various geometries.

PL

W niniejszej pracy wykorzystano komercyjną wersję programu metody elementów skończonych DEFORM™ 3D do symulacji kształtowania blach ze stopu tytanu Ti-6Al-4V metodą dmuchu w matrycy stożkowej o podstawie trójkąta, kwadratu i okręgu. W pracy wykorzystano pełne trójwymiarowe elementy dyskretyzujące rozpatrywany materiał. Ponadto założono sztywno plastyczny model materiału z jednorodnymi oraz izotropowymi własnościami. Symulacja dostarczyła informacji na temat zależności pomiędzy tarciem, grubością próbki i wartościami kryterium pękania a uzyskanymi wartościami intensywności naprężeń, odkształceń, uszkodzeń i prędkością odkształcenia. Uzyskane wyniki symulacji potwierdziły przydatność programu DEFORM™ 3D do modelowania kształtowania metodą dmuchu blach ze stopu tytanu w matrycach o kształcie ostrosłupa.

8

Ochrona hipoteki

80%

Warciński M.

Zeszyty Prawnicze BAS

|

2023

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nr 4(80)

42-62

EN

The subject of this paper is the analysis of the legal nature, construction, substance and conditions of application of three claims for protection of the mortgage regulated in Articles 91–93 of the Act on Land and Mortgage Register and Mortgage. Prevention claim under Article 91 of the above-mentioned Act is aimed at prevention of damage to mortgage creditor caused by reduction of value of the object of mortgage, infringing the security of this right. Claims under Articles 92 and 93 of the above-mentioned Act are relate to the compensation for damage already caused to the mortgage creditor due to the decrease of the value of the object of the mortgage and infringement of mortgage security.

9

Analysis of hybrid CSA-DEA method for fault detection of cracked structures

80%

Sahu S. , Kumar P. B. , Parhi D. R.

Journal of Theoretical and Applied Mechanics

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2019

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tom Vol. 57 nr 2

369--382

EN

Formation of damage in a structural element often causes failures which is not desirable at all by a maintenance team. Identification of location and severity of damage can aid in taking necessary steps to reduce catastrophic failures of structures. As a result, non-destructive methods of damage detection have gained popularity over the last few years. In this paper, a method of damage detection is proposed to identify the location and severity of damage by hybridising a clonal selection algorithm with a differential evolution algorithm. The inputs to the hybrid system are the relative values of the first three natural frequencies of the damaged structure, and the outputs are relative crack locations and relative crack depths. For training the hybrid system, the natural frequencies are found out using finite element analysis and experimental analysis for different crack locations and crack depths. The test results from the proposed hybrid method are compared with finite element analysis and experimental analysis for validation, and satisfactory outcomes have been observed.

10

Research on vibration evolution of a ball bearing without the cage under local variable-diameter raceway damage

80%

Zhou E. , Zhao Y. , Zhang H.

Journal of Theoretical and Applied Mechanics

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2023

|

tom Vol. 61 nr 1

129--146

EN

This article presents an analysis of vibration evolution of a ball bearing without the cage. A vibration model in which time-varying displacement, time-varying stiffness, contact force and collision force are comprehensively considered, is proposed. On this basis, the law of motion of the bearing is studied. It is shown that a variable-diameter raceway affects the radius of curvature, which effects the dispersion of rolling elements. The damaged variable -diameter raceway leads to discrete failure, contact force and collision force of rolling elements, which are main reasons that cause vibration mutation. The bearing motion changes from quasi-periodic to chaotic motion.

11

Implementation of continuum damage in elasto- viscoplastic constitutive equations

80%

Ambroziak A. , Kłosowski P. , Nowicki M. , Schmidt R.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2006

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tom Vol. 10, No 2

207-220

EN

Modelling of the continuum damage framework, is developed for application in the elasto-viscoplastic Chaboche constitutive model. A brief description of the basic variant of the Chaboche model equations is given, followed by a discussion of the most important assumptions necessary to obtain evolution of the continuum damage model and its appli-cation to the open FE commercial program. A consistent presentation of the two proposed approaches is followed by numerical examples.

12

La responsabilité du fisc pour les dommages causés par les fonctionnaires d’état à la lumière de la jurisprudence de la cour suprême

80%

Łętowska E.

Contemporary Central and East European Law

|

1973

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nr 20

19-36

13

Analiza uszkodzeń przewodów rozdzielczych w dużym systemie wodociągowym

80%

Pawełek J. , Wojdyna M.

Gaz, Woda i Technika Sanitarna

|

2001

|

tom Nr 2

49-54

EN

Characteristics of water supply system in Warsaw. Amount of damage and its causes, considering conduits' diameter and material. Unit frequency of damage. Comparative analysis with other cities.

14

Evaluation of the effectiveness of repairs carried out of centres of the road transport

80%

Wdzięczny A.

Journal of Polish CIMAC

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2012

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tom Vol. 7, no 3

361-368

EN

The transport systems and especially the means of transport are the sources of life and health hazard and the natural environment pollution. Exploitation process influence on the elements of the technical objects and decrease the values of the important features of them. This is the mechanism of the damage process. Wear factors could be divided into two groups. One of them are the factors results from the bed operation of the object operators and the second group consists of the factors results from the environment interaction. The damages are the events which are very important from the reliability point of view because are the reason of the partly or full disability. In the paper the damage is defined as the exceeding the acceptable thresholds of the technical object important features.

15

Anisotropic damage evolution in shock wave-loaded viscoplastic plates

80%

Stoffel M.

Archives of Mechanics

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2008

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tom Vol. 60, nr 4

285-301

EN

In the design of structural elements, which are used for protection against explosions, the damage evolution until failure has to be predicted in numerical simulations. However, in the literature a wide variety of damage models is available based on different approaches, e.g. phenomenological and micromechanical theories. Furthermore, the consequences of connections between new damage models and the constitutive equations accounting for elastic-viscoplasticity are unclear. The same problem occurs if structural theories, involving hypotheses, are combined with damage laws. In order to verify the calculated results, experiments with structures subjected to pressure waves are necessary. For this reason, an experimental validation method by means of shock tubes is used in the present study to verify the isotropic and anisotropic damage models. The measured deformations and experimentally observed failure modes can then be compared to the simulated results.

16

Mechanizmy uszkodzeń ceglanych nadproży łukowych

80%

Orłowicz R. , Nowak R.

Wiadomości Konserwatorskie

|

2009

|

tom Nr 26

253-259

PL

Niniejszy artykuł zawiera aktualną wiedzę o budowie łukowych nadproży. Zostało udowodnione, że dobrze znana teoria różni się od faktycznych prac budowlanych i że sprawdza się tylko w sporadycznych przypadkach. Dokonano analizy danych typowych typów morfologicznych pęknięć i rys. Wydział Inżynierii lądowej i Architektury Zachodu pomorskiej Politechniki rozpoczął badanie nad opisanym zagadnieniem.

EN

The following article contains the current knowledge about construction of arched lintels. It had been proved that well - known theory differs from actual construction work and it proves correct only in occasional cases. There was made statistic analysis of typical morphological types of cracks and scratches. Department of Civil Engineering and Architecture in The West Pomeranian University of Technology has started research on the described issue.

17

Przyczyny uszkodzeń i naprawa wybranych zabytkowych sklepień ceglanych

80%

Rzeszotarski A. , Orłowicz R. , Nowak R.

Wiadomości Konserwatorskie

|

2009

|

tom Nr 26

260-269

PL

W referacie omówiono dwa przykłady zastosowania szkła o dużych rozpiętościach, pełniącego funkcje konstrukcyjne, do ekspozycji elementów zabytkowych w budynkach. Szkło, ze względu na swą przezierność i neutralność architektoniczną pozwala na zachowanie cennych elementów zabytkowych tak, że pozostają one wbudowane tam, gdzie je odkryto, mogą być elegancko wyeksponowane, a jednocześnie funkcja budynku nie jest w żadnym stopniu zaburzona. To rozwiązanie jakże częstych dylematów przy pracy z budynkami historycznymi: funkcjonalność nowoczesności - czy zachowanie historycznych wartości? Co poświęcić kosztem czego? Omówiona technologia w wielu przypadkach będzie rozwiązaniem zaspokajającym obie te potrzeby. A kluczowym argumentem może być jej łatwa dostępność i możliwość realizacji tu w Polsce.

EN

The lecture describes two examples of the application, where a wide range glass is being used, as a structural component, in order to expose historic parts of the building. Glass, being transparent and architectural neutral allows preserving valuable historic elements especially that they remain integrated just as they were discovered, yet elegantly displayed, while at the same time none of the building's function is impaired. It is a solution for common dilemmas when working with a historic building: functionality of modern ways or rather preserving its historic value? Which will be scarified as a cost? The described technology in many cases will fulfils both of those needs equally. And the key argument could be its availability and capability for its realization here in Poland.

18

Nonlinear elastic waves for evaluation of composite material deterioration

80%

Lammering R. , Rauter N.

Engineering Transactions

|

2016

|

tom Vol. 64, iss. 4

597--604

EN

This work deals with numerical investigations on nonlinear wave propagation in order to detect micro-damage in composite material. For this purpose two models are under consideration. First, a wave guide with linear-elastic material behavior with and without a crack is analyzed. The nonlinearity of this model is due to the strain tensor as well as the contact of the crack surfaces. Secondly, a hyper-elastic waveguide with a nonlinear constitutive description is considered. It is shown, that the nonlinearity gives rise to second harmonic wave modes which which may be considered as an indicator of micro-damage and material deterioration.

19

Harmful Damage of Enhanced Danger: Economic and Legal Aspects

80%

Ivanov Y. , Kurilina O. , Protsiuk T. , Podoliak E. , Khytra O.

Path of Science

|

2018

|

tom 4

|

nr 8

3001-3008

EN

The article is devoted to the study of the legal nature of liability for damage caused by the source of enhanced danger. The conditions and grounds for liability for damage caused by a source of enhanced danger are considered. Determine the obligation to insure civil liability in obligations to compensate for damage caused by a source of enhanced danger. The scientific novelty is to analyze the national legislation on the legal regime of the source of high danger and to identify the elements of the danger of such sources.

20

Szacowanie kryteriów oceny stopnia zdegradowania funkcjonalnych elementów nawierzchni lotniskowych wykonanych z betonu cementowego na podstawie danych uzyskanych z eksploatowanych obiektów

80%

Barszcz P. , Wesołowski M.

TTS Technika Transportu Szynowego

|

2015

|

tom R. 22, nr 12

93--98, CD

PL

Szacowanie kryteriów oceny stopnia zdegradowania funkcjonalnych elementów nawierzchni lotniskowych wykonanych z betonu cementowego na podstawie danych uzyskanych z eksploatowanych obiektów. Istotnym czynnikiem, który ma wpływ na bezpieczeństwo wykonywanych operacji lotniczych jest właściwe zarządzanie lotniskami w oparciu o uzyskane w sposób systemowy informacje o stanie technicznym nawierzchni ich elementów funkcjonalnych. Jednym z parametrów w oparciu o które szacuje się stan techniczny nawierzchni lotniskowych jest ocena stopnia ich zdegradowania prowadzona w oparciu o stwierdzone uszkodzenia i przeprowadzone naprawy. Takie podejście pozwala na oszacowanie niezbędnych zasobów potrzebnych do wykonania napraw i racjonalne zaplanowanie remontów. Wskaźnik oceny stopnia zdegradowania powierzchni badanej nawierzchni obliczany w oparciu o obmiarowane uszkodzenia i naprawy pozwala na całościową ocenę ich zdegradowania. Podstawową informacją niezbędną do oceny stopnia zdegradowania nawierzchni jest pozyskanie danych z przeprowadzonych przeglądów metodą wizualną a następnie zinwentaryzowanie ich. W oparciu o uzyskane dane o uszkodzeniach i wykonanych naprawach analizuje się stopień zdegradowania nawierzchni lotnisk i na tej podstawie określa się kryteria ich oceny. Badanie metodą wizualną, mimo swojej pozornej prostoty, jest trudne do wykonania. Kwalifikacja uszkodzeń czy napraw do odpowiedniej grupy często nie jest jednoznaczna, dlatego też proces inwentaryzacji powinien być unormowany.

EN

Proper airfield management based on systematically acquired data concerning technical condition of pavement functional elements constitutes an important factor influencing the safety of conducted aviation operations. One of the parameters on the basis of which the technical condition of airfield pavements is determined, is the assessment of its deterioration level performed on the basis of observed damages and made repairs. This approach enables to determine the resources needed to carry out repairs and perform rational planning of overhauls. The pavement deterioration level index, calculated on the basis of measured damages and repairs, enables overall technical condition assessment of the analyzed pavement. The basic information needed for the airfield pavement deterioration assessment is data acquired from reviews using visual method and subsequent making an inventory of it. Basing on the acquired data concerning damages and repairs, the airfield pavement deterioration level is analyzed and on this basis criteria of its assessment are determined. The research using visual method, despite seeming quite simple, is difficult to carry out. The qualification of damages and repairs for an appropriate group is often ambiguous, which is why the process of making an inventory should be standardized.