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PL
W pracy przedstawiono wyniki badań odbiorczych drogowego obiektu o konstrukcji gruntowo-powłokowej. Powłokę obiektu zaprojektowano z blachy o obecnie najwyższym profilu UltraCor. Parametry analizowanego obiektu odniesiono do obecnie rekordowych konstrukcji. Standardowe badania rozszerzono o analizę skuteczności obciążeń zmieniających położenie, czyli ruchomych ale w układzie quasi statycznym. Bazą pomiarową była górna część pasma obwodowego powłoki z czujnikami indukcyjnymi i zegarowymi do wyznaczania ugięcia w regularnych odstępach. W pracy podano kolejny przykład powstawania „pętli histerezy” w przypadku stosowania cyklu obciążenia ruchomego, w którym realizuje się przejazd pierwotny po obiekcie z nawrotem po tym samym torze ruchu. W przypadku gęstej siatki punktów pomiarowych możliwe jest stosowanie algorytmu różnicowego do szacowania momentów zginających w blasze falistej. W przykładzie wskazano na wielokrotnie mniejsze siły wewnętrzne i przemieszczenia w przypadku obciążeń ruchomych niż w powstałych podczas budowy obiektu. Celem pracy jest wskazanie na specyfi czne zachowanie się konstrukcji gruntowo-powłokowych w odniesieniu do klasycznych mostów o kształcie łukowym.
EN
In this paper the results of the live load tests of soil steel bridge are presented. The structure was designed with use of the largest possible corrugation type UltraCor. Parameters of analysed structure were referred to the current record structures in the term of span. Standard test procedure have been expended to check the efficiency of the position-changing loads i.e live loads but in a quasi-static approach. The measuring base was the upper part of the shell periphery equipped with inductive and dial gauges to determine deflections at regular layout. Paper presents another example of the formation of “hysteresis loop” where the live load is passing back and forth along the same path. In the case of a dense layout of measuring points it is possible to use a differential algorithm to estimate the bending moments in corrugated steel plates. Analysed case shows that the internal forces and displacements due to the live loads are much smaller than during construction. The purpose of the paper is to indicate the specific behaviour of soil-steel structures in relation to classical Arch bridges.
EN
The use of expert systems in the world of civil engineering, and in particular for roads, has become a necessity for the reason of the particularity, complexity, and diversity of the influencing parameters at the level of the design calculation, the latter of which represents the major source of subsequent degradation. This system consists of proposing a tool for helping the user firstly to size the body of the roadway, with several analytical methods and models (Pre-project, Boussinesq, Westgaard, and Burmister), and secondly, to offer different design possibilities (thickness and type of the material) that make up the layers. Lastly, it is to calculate the stresses and strains in order to compare them with admissible limits. The management of a knowledge base of complex natures (words, sentences, numbers, symbols, tables, calculation methods, equations, conditions, etc.) requires an adequate methodology which goes beyond the simple use of the technology but enables you to imagine the process of regrouping this mass of complex data and classifying the data, which can then be integrated into a database or spreadsheets and external programs designed with code compatible with the expert system generator. Our contribution relates initially to the formulation, organization, and preparation of the algorithms, and then the starting of the programs in order to conceive fully executable programs, the latter of which we can call the expert system. The validation of such a system was made as the work progressed, changes were made in the formulation of the rules, and the order and orientation of the data in the knowledge that the advantage of this type of system is the possibility of permanently reinforcing the database with human expertise in the field, or in books, especially so that we can avoid data loss due to illnesses, retirement, etc.
PL
W artykule zaprezentowano wyniki licznych obliczeń porównawczych dla obciążeń podróżujących z różnymi prędkościami po mostach różnej długości. Wyniki przedstawiono w postaci wykresów linii ugięcia i kątów skręcenia dla obciążenia poruszającego się po moście i jadącego dalej po zjechaniu z niego. Zamieszczono także zestawienia prędkości krytycznych dla mostu o konkretnej długości i długości krytyczne mostów dla określonej prędkości podróżującego obciążenia.
EN
The paper presents results of numerous comparative calculations for loading travelling with different velocities along bridges with some length. The results are presented here in the form of deflection and torsion lines for loading moving on bridge and next after descending bridge. There are given also comparisons of critical velocities for bridge with given lengths and critical lengths for bridge with given (assumed) velocity of moving load.
EN
This paper presents an analysis of the vibrations and displacements of the tool during the turning of hardened steel for various turning parameters. Studies have shown that an increase in feed from 0.1 to 0.35 mm / rev results in an almost two-fold increase in radial displacement of the tool. It has also been shown that the combination of high feeds and high rotational speed of the workpiece causes a rapid increase in vibration in all directions.
5
Content available remote A study of displacements of structures in the vicinity of deep excavation
EN
In the article the aspects concerning the excavation impact and values of displacements of the ground and existing structures in the vicinity of deep excavations are presented. Four cases of excavations in typical Quaternary soils of Warsaw executed in the close proximity to the existing metro tunnels (and station) are described with special emphasis put on the description and analysis of experimental data including in-situ measurements of vertical displacements of existing metro structures. The discussion and conclusions on the displacements of structures (EPB TBM tunnels with segmental lining and cubature metro stations) in the vicinity of excavations depending on their location relative to excavation are presented. Typical ranges of displacements in relation to the depth, distance and type of structures influenced by deep excavations are given. Equation for the prediction of vertical displacements of TBM tunnels in the vicinity of deep excavation is formulated. In addition, the 2D finite element modelling of one of the described example cases is made and presented in detail. The results of FE analysis are compared to the actual experimental monitoring data.
EN
The article presents an example of supplementing geotechnical monitoring with geodetic observations. The experimental flood embankment built within the ISMOP project (Information Technology System of Levee Monitoring) was subjected to continuous monitoring based on built-in measuring sensors. The results of geodetic monitoring used for observation of earth-filled flood embankment subjected to external loads are presented in the paper. The tests were carried out on an experimental flood embankment forming a closed artificial water reservoir. The observations were carried out for two purposes. The first was long-term monitoring, which was aimed to determine the behaviour of the newly built embankment. The second purpose was to check the reaction of the levee to the simulated flood wave, caused by filling and draining the reservoir. In order to monitor the displacements of the earth-filled embankment, it was necessary to develop the proper methodology. For the needs of research works, an appropriate network of 5 reference points and 48 survey markers has been designed and established. The periodic measurements were carried out using precise robotic total station. The stability of the reference frame was each time checked and displacements of survey markers were determined based on it. The final results allow to reveal the reaction of levee to external loads. The displacement values were referred to the course of the filling and draining experiment to indicate the relationship between them. In the field of long-term monitoring the results clearly imply the dominance of displacements outside the reservoir for points located on the embankment, in contrast to points on the crest and foreground, which do not show significant movements. On the other hand, in the field of testing the embankment reaction to the flood wave, obtaining reliable results was possible thanks to high-accuracy geodetic measurements. Small displacement values, often at the level of their determination errors, were averaged for groups of points with the same height of foundation. A sizable number of points allows to perceive some tendencies and the relation between embankment soaking and its movement directions can be noticed. During periods when the levee was still saturated with water, slight movements outside the reservoir were revealed. On the other hand, the following period of drying caused movement in the opposite direction.
7
Content available remote Analiza wytrzymałościowa belki opryskiwacza z wykorzystaniem systemów CAD/CAE
PL
Przedstawiono wyniki analizy wytrzymałościowej belki nośnej opryskiwacza firmy Pilmet. Po utworzeniu numerycznego modelu belki przeprowadzono analizę statyczną. Wyznaczono naprężenia i przemieszczenia metodą elementów skończonych dla różnych wariantów położenia składanej belki.
EN
Presented are the results of strength analysis of the Pilmet boom sprayer. After creating the numerical model of the boom, a static analysis was carried out. Stresses and displacements were determined using the finite element method for different variants of the folding boom position.
EN
The subject of the research is a footbridge across the river Brda in Bydgoszcz. The measurements of the footbridge displacements with the test load were undertaken. The paper presents the results of the measurements and compares them with the theoretical results obtained using the finite element method (FEM). On this basis, discrepancy between actual work of the structure and numerical simulations was found. Attempt to explain the reasons for the observed differences and direction of further research were included in the conclusions.
PL
Przedmiotem przeprowadzonych badań jest kładka przez rzekę Brdę w Bydgoszczy. W ramach badań wykonano pomiary przemieszczeń kładki przy przyłożonym próbnym obciążeniu. W artykule przedstawiono wyniki przeprowadzonych pomiarów oraz porównano je z wynikami teoretycznymi otrzymanymi przy zastosowaniu metody elementów skończonych (MES). Na tej podstawie stwierdzono rozbieżności pomiędzy rzeczywistą pracą konstrukcji a symulacjami numerycznymi. We wnioskach podjęto próbę wyjaśnienia przyczyn zaobserwowanych różnic oraz wskazano kierunek dalszych badań.
EN
The paper deals with the plane problem of an elastic layer resting on a Winkler foundation with an emptiness. The stresses in the layer are caused by a given normal loading on its upper boundary plane. The mathematical formulation of the problem leads to a mixed boundary value problem and it is solved using Fourier transform methods and Fredholm integral equation of the second kind. The detailed analysis is derived analytically and numerically for an elliptic distribution of boundary loadings. The results for the normal displacement and the stresses on the lower boundary of the layer are presented in figures.
EN
Hip replacement surgery, by introducing a specific replacement head on the stem and cup, completely changes the conditions of co-operation typical for the biological correct pair. The clinical selection of endoprosthesis, apart from other conditionings, involves a dilemma between the choice of a rigid tribological node and the selection of a susceptible bearing cushioning the locomotive loads. The aim of the study is to evaluate the coefficient of friction and wear resistance of materials used for sliding contact in the endoprostheses of hip joints. On the basis of the conducted tests, it can be stated that, in the selection of material for cups of endoprosthesis, the wear resistance is important, and the coefficient of friction in contact head and cup in the prosthesis is less important. The presence of significant disproportions between the two parameters of the tribological process proves that the biomaterial is less useful on the cup. In the assessment of cooperation in the endoprosthesis, simulations of the contact of structural elements are useful, because, on that basis, in the correlation with tribological parameters, one can make conclusions about the distribution of stresses and displacements that may determine the lifetime of the implant.
PL
Zabieg alloplastyki stawu biodrowego poprzez wprowadzenie określonej zamiennej głowy na trzpieniu i panewki zmienia całkowicie warunki współpracy charakterystyczne dla biologicznej prawidłowej pary. Kliniczny dobór endoprotezy, oprócz innych uwarunkowań, wiąże się z dylematem pomiędzy wyborem sztywnego węzła tribologicznego a wyborem biołożyska podatnego, amortyzującego obciążenia lokomocyjne. Celem pracy jest ocena współczynnika tarcia i odporności na zużycie materiałów stosowanych na panewki do kontaktu ślizgowego w endoprotezach stawu biodrowego. Na podstawie przeprowadzonych badań można stwierdzić, że w doborze materiału na panewkę endoprotezy ważna jest odporność na zużycie ścierne, a nieco mniejsze znaczenie ma współczynnik tarcia w kontakcie z głową endoprotezy. Występowanie znacznych dysproporcji między tymi dwoma parametrami procesu tribologicznego świadczy o słabszej przydatności biomateriału na panewki endoprotez. W ocenie współpracy w endoprotezie przydatne są symulacje kontaktu elementów konstrukcyjnych, ponieważ na ich podstawie, w korelacji z parametrami tribologicznymi, można wnioskować o rozkładach naprężeń i przemieszczeń, które będą decydować o żywotności implantu.
EN
Geostatistical methods make the analysis of measurement data possible. This article presents the problems directed towards the use of geostatistics in spatial analysis of displacements based on geodetic monitoring. Using methods of applied (spatial) statistics, the research deals with interesting and current issues connected to space-time analysis, modeling displacements and deformations, as applied to any large-area objects on which geodetic monitoring is conducted (e.g., water dams, urban areas in the vicinity of deep excavations, areas at a macro-regional scale subject to anthropogenic influences caused by mining, etc.). These problems are very crucial, especially for safety assessment of important hydrotechnical constructions, as well as for modeling and estimating mining damage. Based on the geodetic monitoring data, a substantial basic empirical material was created, comprising many years of research results concerning displacements of controlled points situated on the crown and foreland of an exemplary earth dam, and used to assess the behaviour and safety of the object during its whole operating period. A research method at a macro-regional scale was applied to investigate some phenomena connected with the operation of the analysed big hydrotechnical construction. Applying a semivariogram function enabled the spatial variability analysis of displacements. Isotropic empirical semivariograms were calculated and then, theoretical parameters of analytical functions were determined, which approximated the courses of the mentioned empirical variability measure. Using ordinary (block) kriging at the grid nodes of an elementary spatial grid covering the analysed object, the values of the Z* estimated means of displacements were calculated together with the accompanying assessment of uncertainty estimation – a standard deviation of estimation σk. Raster maps of the distribution of estimated averages Z* and raster maps of deviations of estimation σk (in perspective) were obtained for selected years (1995 and 2007), taking the ground height 136 m a.s.l. into calculation. To calculate raster maps of Z* interpolated values, methods of quick interpolation were also used, such as the technique of the inverse distance squares, a linear model of kriging, a spline kriging, which made the recognition of the general background of displacements possible, without the accuracy assessment of Z* value estimation, i.e., the value of σk. These maps are also related to 1995 and 2007 and the elevation. As a result of applying these techniques, clear boundaries of subsiding areas, upthrusting and also horizontal displacements on the examined hydrotechnical object were marked out, which can be interpreted as areas of local deformations of the object, important for the safety of the construction. The effect of geostatistical research conducted, including the structural analysis, semivariograms modeling, estimating the displacements of the hydrotechnical object, are rich cartographic characteristic (semivariograms, raster maps, block diagrams), which present the spatial visualization of the conducted various analyses of the monitored displacements. The prepared geostatistical model (3D) of displacement variability (analysed within the area of the dam, during its operating period and including its height) will be useful not only in the correct assessment of displacements and deformations, but it will also make it possible to forecast these phenomena, which is crucial when the operating safety of such constructions is taken into account.
PL
Omówiono zagadnienie geometrycznego modelowania frezu walcowego oraz obliczania jego ugięć pod wpływem obciążeń odwzorowujących siły skrawania występujące podczas frezowania powierzchni wyrobu ze stopu Al 7075. W modelowaniu uwzględniono 2 modele przestrzenne frezu walcowego: z prostoliniowymi krawędziami skrawającymi oraz ze śrubowymi krawędziami skrawającymi. Wzięto pod uwagę oddziaływanie sił skupionych i różnych rozkładów obciążeń odwzorowujących siły skrawania. Wyciągnięto wnioski dotyczące wpływu kąta nachylenia sił względem wybranej osi układu współrzędnych na generowane naprężenia zredukowane i deformacje frezu. Do obliczenia pól przemieszczeń, odkształceń i naprężeń wykorzystano metodę elementów skończonych.
EN
The problem of geometric modeling of the plain milling cutter and its deflection under the influence of loads mapping forces occurring during the milling of the Al 7075 alloy surface is discussed. In modeling, 2 types of plain milling cutters are included: with rectilinear cutting edges and with helical cutting edges. The influence of concentrated forces and different distributions of loads mapping the cutting forces, is considered. Conclusions are drawn regarding the influence of the force inclination angles relative to the selected axis of the coordinate system on the generated effective stresses and cutter deformations. The finite element method was used to calculate the displacements, deformations and stresses.
EN
The paper presents the analysis of the II Underground Line construction’s impact on the Warsaw Scarp with the use of the electrical resistivity imaging (ERI, also known as the electrical resistivity tomography) and further total station position measurements. The underground passes under the scarp perpendicular in the area of Dynasy Street 6, in Downtown district. The electrical resistivity imaging was performed for recognition of the geological structure and a potential landslide surface or zone. The gradient system was used during the prospection. In these analyses, the longitudinal section was 40 m long, and the depth of survey amounted to 6 m. In the case of the 200 m long transverse section, the resulted depth of survey was 30 m. The geophysical image of the longitudinal section, does not contain loosening soil zones, which could indicate slip surface. Next, total station measurements, which were tied to the archival geodetic observations’ results, were carried out. The aim of the measurements was to verify the activity of the horizontal and vertical displacements. The TBM excavation process led to summary vertical displacements up to approx. 24 mm and horizontal displacements amounting to approx. 13 mm. To sum up, the current land surveys reveals minor underground line’s construction impact on the scarp displacement. Nevertheless, the sensitive urban environment requires further monitoring, especially that the operation loads can result in displacement rate change.
EN
Corrugated steel plates are highly rigid and as the constructions can be immersed in soil, they can be used as soil-steel structures. With an increase of cover depth, the effectiveness of operating loads decreases. A substantial reduction of the impacts of vehicles takes place as a road or rail surface with its substructure is crucial. The scope of load’s impact greatly exceeds the span L of a shell. This article presents the analysis of deformations of the upper part of a shell caused by a live load. One of the assumptions used in calculations performed in Plaxis software was the circle-shaped shell and the circumferential segment of the building structure in the 2D model. The influence lines of the components of vertical and horizontal displacements of points located at the highest place on the shell were used as a basis of analysis. These results are helpful in assessing the results of measurements carried out for the railway structure during the passage of two locomotives along the track. This type of load is characterized by a steady pressure onto wheels with a regular wheel base. The results of measurements confirmed the regularity of displacement changes during the passage of this load.
PL
W artykule omówiono zagadnienie numerycznego modelowania ugięć cienkiej ścianki półwyrobu kształtowanego w procesie frezowania frezem walcowym. Opracowany model obliczeniowy jest dwuwymiarowy i uwzględnia zjawiska przenoszenia nacisków w obszarze styku między frezem a obrabianą ścianką. Do obliczenia przemieszczeń, odkształceń oraz naprężeń zastosowano metodę elementów skończonych.
EN
In the paper there is described the problem of numerical modeling of deflections of thin wall in the process of milling using plain milling cutter. Developed numerical model is two-dimensional and takes into consideration the distribution of pressure phenomena between the milling cutter and manufactured wall. For computing displacements, strains and stresses the finite element method was used.
EN
The article presents the analysis of FRP composite materials strengthening systems for pre-stressed bridge structure elements. Displacements and strains of main beams of bridges were investigated before and after the strengthening executed by FRP composite materials. Test load field and theoretical analysis were performed after bridge structure repair. The results of bridge structures after strengthening in field load tests allowed for an assessment of the efficiency of the strengthening, as well as establishment of guidelines for future reference concerning this type of maintenance in the engineering practice.
PL
W pracy przedstawiono metodykę określania zmian stanu geometrycznego konstrukcji zawierającą sposób prowadzenia pomiarów oraz możliwe do zastosowania warianty obliczeniowe. Obiektem badań szczegółowych, których wyniki prezentowane są w pracy jest przekrycie wiszące Amfiteatru w Koszalinie. W badaniach wykorzystano bazę danych o obiekcie, zawierającą wyniki ponad 40 pomiarów okresowych konstrukcji z okresu 2006-2015 r. a, prowadzonych w różnych (rejestrowanych podczas pomiarów) warunkach zewnętrznych - również przy różnym obciążeniu temperaturą oraz śniegiem i lodem. Wyniki wcześniejszych badań prowadzonych na obiekcie testowym m.in. (Deska 2013; Kaczmarek i Śpiewak 2014b), a także prowadzone dla innych konstrukcji (Odziemczyk 2014) zwracają uwagę na istotny wpływ obciążenia konstrukcji stalowych temperaturą, a tym samym konieczność jego uwzględnienia przy ocenie stanu geometrycznego, określaniu przemieszczeń, przede wszystkim w warunkach dodatkowego obciążenia śniegiem i lodem. W pomiarach okresowych wykorzystano tachimetr elektroniczny i metodę biegunową z zastosowaniem stanowiska swobodnego. W obliczeniach wykorzystano metodę porównawczą (różnic współrzędnych) oraz wykorzystano narzędzia analizy statystycznej i opracowane wcześniej w oparciu o nie modele obliczeniowe. Porównano wyniki otrzymywane z wykorzystaniem obu podejść i poddano je ocenie wskazując zarówno ich możliwości jak i istotne ograniczenia. Zastosowanie zaproponowanej metodyki zapewnia prawidłowe określenie zmian stanu geometrycznego konstrukcji, a wykorzystanie w obliczeniach obu wariantów umożliwia wiarygodną kontrolę.
EN
The paper presents the methodology to determine changes in the geometric structure containing the conducted measurements and feasible variants of calculations. The object of detailed studies, whose results are presented in this work, is the suspended roof of the open-air theatre in Koszalin. In the research conducted since 2006, a database that contains the results of more than 40 periodic measurements of the structure carried out in different (registered during measurements) external conditions (including different temperature, snow and ice load) was used. The previous research conducted at this facility, among others, (Deska 2013, Kaczmarek and Śpiewak 2014b), as well as for other structures (Odziemczyk 2014) draws attention to the important influence of the temperature load of steel structures and hence the need for its consideration when assessing the geometric state. Electronic total station and the polar method with free stationing were used in periodic measurements. The calculations used a comparative method (differences of coordinates) and tools of a statistical analysis as well as developed calculation models based on them. The results obtained using both approaches were compared and assessed by indicating both their possibilities and significant limitations. The application of the suggested methodology provides the correct determination of changes in the geometric state of a construction and the use of the variants in calculations enables a reliable control.
EN
The investigation of technical condition of cooling towers is an important engineering issue. Regulations regarding safe operations of high structures force periodic measurements in order to determine technical state of such towers. This paper presents the processing methodology of laser scanning data and shows computation results of cooling tower W-1 shape changes. These results were referred to the designed shape of the tower in question. Tower surface displacements (deformations) are shown by plotting the deviations of the measured shape from the regular one. The determined changes in the surface shape are between –20 cm and 5 cm. This article presents the evaluation of the technical condition of the W-1 cooling tower.
PL
W artykule przedstawiono wyniki symulacji statycznej i dynamicznej fotelika samochodowego do przewozu dziecka.
EN
The article presents the results of static and dynamic simulations of the child car seat.
EN
This paper analyzes the distribution of internal forces and displacements of embedded retaining wall in Quaternary deposits and Tertiary clays. Calculations have been based on the Subgrade Reaction Method (SRM) for two different types of earth pressure behind the wall (active, at-rest) in order to show the differences resulting from adopting the limit values. An algorithm for calculation of “cantilever wall” using the Mathematica program was proposed.
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