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EN
Airlie beach houses are quite common in the coastal areas of Australia. These houses, similar to other buildings, provide comfort for their residents. House comfort is not limited to temperature or sound pollution, vibration can be considered as another equally important factor. In this article, the vibration of an Airlie beach house was investigated. The base steel structure was modeled in SolidWorks and Space Gass for evaluating stress distribution and nodal displacement, respectively. To find the root cause of the distressing vibration of the house, which was felt with dwellings, the axial acceleration of the house’s structure was determined. Some feasible solutions such as adding a fiber-reinforced polymer joist hanger, inserting additional rubber padding to the joist hanger, and attaching additional bracing, were discussed and a cost analysis was considered for the solutions. Eventually, the nature of the best solution, which was adding rubber, was tested experimentally.
PL
W trzeciej części cyklu artykułów dotyczących zginanych ścian murowanych, obciążonych prostopadle do ich powierzchni [5, 6] omówiono sposoby analizy tego rodzaju konstrukcji, w tym założenia dotyczące warunków brzegowych modeli ścian jednowarstwowych i szczelinowych. Przedstawiony został również sposób określania wartości momentów zginających przyjęty w normie PN-EN 1996-1-1.
EN
In the third part of the series of articles on bent masonry walls, loaded perpendicular to their surfaces [5, 6], methods of analysis of this type of structure are discussed, including assumptions regarding the boundary conditions of single-leaf and cavity wall models. The method of determining the values of bending moments adopted in the PN-EN 1996-1-1 standard is also presented.
EN
The paper presents the results of mechanical and tribological tests conducted on the surface of Al-Si-Cu/SiCp composite reinforced with SiC particles and modified by friction stir processing (FSP) with different parameters. Changes in the distribution of the reinforcement particles on the modified surface of the composite were calculated and analyzed using a new analytical RVE theory with Eisenstein-Rayleigh-Mityushev sums (ERM-sum) (see the definitions below), and PointSel software. The Vickers hardness test with a 1 N load and the ball-on-disc method were used to test the material properties. A high degree of homogenization of the tested material was observed as a result of its modification, as evidenced by an approximately 4-fold reduction in the size of representative volume element (RVE) cells. The size of the RVE cell decreased almost four times for the material after modification, which indicates the high level of homogenization of the tested material. Moreover, we observed a reduction by order of magnitude of the anisotropy coefficient of the distribution of the reinforcing phase particles after the modification process. A 30% increase in the Vickers microhardness of the representative areas was obtained for the modified composites. After the FSP modification process the friction coefficient increases by 40%, and almost 25% decrease in the specific wear rate is observed. Both effects are attributed to the achieved homogenization of particle distribution and reduction of particle size up to 38%.
PL
Przedstawiono wyniki badań właściwości mechanicznych i tribologicznych powierzchni kompozytów Al-Si-Cu/SiCp modyfikowanych metodą FSP z różnymi parametrami. Zmianę rozkładu cząstek wzmacniających na powierzchni kompozytu zbadano z wykorzystaniem nowej analitycznej teorii RVE oraz ERM-sums i programu PointSel. Testy twardości przeprowadzono metodą Vickersa przy obciążeniu 1 N, a testy ścieralności wykonano metodą ball-on-disc. Po procesie modyfikacji stwierdzono wysoki stopień homogenizacji, który cechował się około czterokrotnym zmniejszeniem wielkości komórki RVEc oraz spadkiem o rząd wielkości wartości współczynnika anizotropii rozkładu cząstek fazy wzmacniającej. Zaobserwowano około 30% wzrost mikrotwardości Vickersa w modyfikowanym kompozycie. Po procesie modyfikacji FSP stwierdzono również 40% wzrost wartości współczynnika tarcia oraz blisko 25% spadek wartości wskaźnika zużycia, wynikający z ujednorodnienia struktury i redukcji wielkości cząstek SiC, dochodzącej do 38%.
4
Content available remote Structural analysis of KufaSat using ANSYS program
EN
The current work focuses on vibration and modal analysis of KufaSat structure using ANSYS 16 program. Three types of Aluminum alloys (5052-H32, 6061-T6 and 7075-T6) were selected for investigation of the structure under design loads. Finite element analysis (FEA) in design static load of 51 g was performed. The natural frequencies for five modes were estimated using modal analysis. In order to ensure that KufaSat could withstand with various conditions during launch, the Margin of safety was calculated. The results of deformation and Von Mises stress for linear buckling analysis were also performed. The comparison of data was done to select the optimum material for KufaSat structures.
EN
The article presents results of research on the influence of variable parameters of horizontal continuous casting on the structure of AlCu4MgSi (EN AW-2017A) alloy ingots. The special character of the process allows for a continuous change of some of its parameters, namely, of the casting speed and of the rate of the cooling fluid flow thorough the crystallizer. These parameters have a significant impact on the crystallization process of the liquid metal. Depending on the cooling rate, intensity of the convection inside the solidifying alloy, and its chemical composition, there may arise some differences in the structure of the cast. In this study, ingots obtained at different casting speeds have been analyzed. The research methodology, based on light microscopy and electron microscopy (SEM), as well as energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), allowed for a thorough examination of the structure of the studied materials. The results were shown that an increase in the ingot casting speed leads to an increase in the average grain surface area.
6
Content available remote Design of a rice rope laying machine for direct sowing
EN
The research and development of a rice rope laying machine (RRLM) provides new ideas for a design of a rice direct seeding machine, and solves existing problems encountered in direct seeding techniques currently in use. The RRLM has been developed based on an in-depth analysis of the design principles and main structure parameters of rice direct seeding machines. The completed machine consists of all necessary components including an anti-blocking device, sowing device, opening device, banking device, compacting device, etc. The optimal design of the parts and structure of the RRLM was completed using the three-dimensional Unigraphics NX (UG NX) software. The rationale and the performance of the machine and its components were analyzed using this virtual prototyping technology. The key technology problems commonly encountered, which included the opener being easily plugged up, the difficulty in adjusting/controlling the number of seeds per hole, and seeding rope easily broking during the process of laying, have all been effectively solved. The field test results have shown that this machine has the advantage of good maneuverability and high working efficiency, the reliability and quality of seeding rope placement meets (fulfills) the design requirements, the profiling and compacting effect of the machine is very good, and the uniformity of seeding depth and accurate rope placement are guaranteed.
PL
Rozwój gospodarczy miast stawia przed konstruktorami trudne zadania. Jednym z wielu problemów jest posadowienie nowego budynku w zwartej zabudowie. W artykule przedstawiono własne rozwiązanie tego zagadnienia. Zaproponowano podziemny układ konstrukcyjny jako mieszany stalowo-żelbetowy. Wyznacznikiem bezpieczeństwa jest trwałość i niezawodność konstrukcji.
EN
The economic development of cities poses constructors difficult task. The paper presents a new own solution to this problem. The newly designed underground structural system was proposed as a mixed: steel – reinforced concrete. Durability and quality in terms of reliability of the structure, which is a measure of safety is the overarching goal of this publication. In this case, the repairing were made during the design stage.
8
Content available remote Optymalizacja składu betonów z dodatkiem metakaolinitu
PL
W artykule przedstawiono wyniki optymalizacji składu betonu modyfikowanego dodatkiem prażonego kaolinitu (metakaolinitu), użytego jako częściowy substytut cementu. Optymalizację przeprowadzono przy użyciu programu STATISTICA w oparciu o wyniki badań betonów o zróżnicowanym składzie, zdeterminowanym udziałem dodatku metakaolinitu do 15% masy spoiwa oraz stosunkiem woda/spoiwo od 0,35 do 0,54. Badania wykonano według centralnego kompozycyjnego planu doświadczenia, przewidującego wykonanie badań dziewięciu mieszanek betonowych o zróżnicowanym składzie. Jako kryteria optymalizacji przyjęto: maksimum wytrzymałości na ściskanie fc po 28, 90 i 180 dniach dojrzewania betonu, maksimum krytycznego współczynnika intensywności naprężeń KIcS i maksimum współczynnika sprężystości podłużnej E po 28 i 180 dniach dojrzewania betonu, minimum objętości porów powietrznych w betonie A oraz minimalny wymiar fraktalny określony metodą cięciwy DC i metodą pudełkową DBC. Objętość porów powietrznych określono na podstawie analizy płaskich przekrojów betonu metodami stereologicznymi. Analizie fraktalnej poddano uzyskane w badaniu odporności na pękanie powierzchnie przełomów betonów. Optymalizację przeprowadzono dla trzech wariantów I, II i III. Uzyskane wyniki potwierdziły występowanie ścisłej zależności między właściwościami a strukturą betonów, w tym betonów z dodatkiem metakaolinitu. Wykazano także, że ze względu na przyjęte kryteria optymalizacji celowe jest projektowanie betonów przy założeniu względnie niskiego stosunku woda/spoiwo oraz względnie dużego udziału dodatku metakaolinitu.
EN
This paper presents the results of optimization of composition of the concretes modified with calcined kaolin (metakaolinite). The analysis was performed according to the results of investigations base of central composite design of experiment. The amount of metakaolinite used as used as an equivalent of cement varied from 2% to 15% of the mass of binder. Water/binder ratios (w/b) in the mixes were in the range of 0.35 to 0.54. On the basis of multi-criteria analysis, the optimal compositions of concrete mixes were established for the adopted criteria optimization. The optimization criteria were: maximal compressive strength fcafter 28, 90 and 180 days of concrete curing, maximal value of critical stress intensity factor KIcS(maximal fracture toughness) and maximal elastic modulus E after 28 and 180 days of concrete curing, minimal porosity of hardened concrete and minimal value of fractal dimension (divider method DC and box counting method DBC). The optimal solutions were obtained for water/binder ratio below 0.37 and amount of metakaolinite 15% of the mass of binder. The optimum composition is as follows: 388.4 kg of cement, 67.8 kg of metakaolinite, 169.5 l of water, 742.8 kg of sand and 1218.3 kg of basalt.
EN
Influence of the repetitive corrugation on the mechanism occuring during plastic Deformation of CuSn6 alloy This paper presents the research results of Cu$n6 alloy strip at semi-hard state, plastically deformed in the process of repetitive corrugation. The influence of process parameters on the mechanical properties and structure of examined alloy were investigated. Examination in high-resolution transmission electron microscopy (HRTEM) confirmed the impact of the repetitive corrugation to obtain the nano-scale structures. It has been found, that the application of repetitive corrugation increases the tensile strength (Rm). yield strength (Rpo:) and elastic limit (Rpo.os) of CuSn6 alloy strips. In the present work it has been confirmed that the repetitive corrugation process is a more efficient method for structure and mechanical properties modification of commercial CuSn6 alloy strip (serni-hard) as compared with the classic rolling process.
PL
W pracy przedstawiono wyniki badań taśm ze stopu CuSn6 poddanych obróbce plastycznej z zastosowaniem procesu naprzemiennego gięcia. Określono wpływ parametrów procesu na strukturę, teksturę oraz właściwości mechaniczne. Otrzymane wyniki porównano z wynikami uzyskanymi dla taśm walcowanych klasycznie. Wykazano, że dominującą składową w analizowanych taśmach niezależnie od zastosowanego procesu obróbki jest składowa typu Brass. Badania w wysokorozdzielczym transmisyjnym mikroskopie elektronowym potwierdziły wpływ procesu naprzemiennego gięcia na powstanie struktury nanometrycznej w postaci bliźniaków odkształcenia. Wykazano, że po obróbce plastycznej z zastosowaniem procesu naprzemiennego gięcia następuje zwiększenie maksymalnej wytrzymałości na rozciąganie w porównaniu z wytrzymałością taśm walcowanych klasycznie.
EN
The paper presents the results of the study on tapes of CuSn6 alloy after plastic deformation using the repetitive bending process. The influence of process parameters on the structure, texture and mechanical properties was investigated. Obtained results were correlated with the results obtained for alloy subjected to cold rolling. Has been shown that the major texture component of the analyzed tapes regardless of the treatment process is the Brass component. Examination in high-resolution transmission electron microscopy confirmed the impact of the repetitive bending process on formation of nanometric structure in the form of deformation twins. It has been shown that using a repetitive bending process increases the maximum tensile strength in comparison with conventionally rolled tapes.
EN
The concept of spatial criterion of the electron charge concentration is applied to determine the metal melting point. Based on the model proposed for bcc metals, a model for hcp metals and general form for others has been developed. To calculate the melting point, only structural data and atomic number are required. The obtained results show good consistency with the experimental data for metals with atomic number Z < 70.
PL
Praca stanowi rozwinięcie koncepcji kryterium przestrzennej koncentracji ładunku elektronowego jako miary temperatury topnienia metalu. Na bazie modelu zaproponowanego dla metali o sieci bcc został opracowany model dla metali o sieci hcp. Do obliczenia temperatury topnienia wymagane są jedynie dane strukturalne i liczba atomowa. Uzyskane wyniki wykazują dobrą zgodność z danymi eksperymentalnymi dla metali o liczbie atomowej Z < 70.
EN
The article presents a Porter five forces analysis of the Clients of entities who manage seaports. The Clients have been divided into Leaseholders and Carriers. The analysis has been performed by means of a case study for which Szczecin and Świnoujście Seaports Authority has been selected. It is the Clients of enterprises, including port authorities, who represent the market force and have a significant influence on the competitive position of a company. This, of course, does not relate to seaports so straightforwardly. Notwithstanding, the analysis has shown the main groups of clients of the managing entity and importance of relationships between the port authority and Clients for the seaport development and its position in the market in port services. The analysis has shown, which is extremely important, that the importance of particular Clients of the entity managing a seaport is not determined by the revenue of the seaport authority, but what determines it is the importance of a particular group of Clients in the TSL market, which is vitally important in the context of how the seaport authority operates.
EN
Purpose: The main goal of present study is try to find the influence of severe plastic deformation using the ECAP (equal channel angular pressing) process and different processing routes on structure formation, properties and lattice strain of EN AC 51100 alloy. Design/methodology/approach: The cold ECAP behaviour was determined using three different processing routes A, Bc and C and four repetitive pressings. The comparison between three types of processing routes has been established based on microstructure observation, grain size measurements and X-ray diffraction analysis. Findings: It was found that the structure after three types of mechanical treatments is strongly deformed, and the processing route has a significant impact on shape and grain size. It was also found that direction of shearing patterns that appears after deformation have influence on residual stress in ECAPed material. The use of equal channel angular pressing method has also an influence on hardness of investigated alloy which increase more than 90% after four repetitive pressings. Research limitations/implications: Current study presents the investigation results which was carried out on samples, not on final products. Practical implications: Current research is moving towards to develop high strength materials with increased mechanical properties and fine microstructure which are known as ultra-fine-grained materials, compared to well-known common materials. Originality/value: This paper presents the results of structure and properties investigation including X-ray analysis of severely deformed AlMg3 alloy by ECAP process.
14
Content available remote Influence of RCS process on the structure and mechanical properties of CuSn6 alloy
EN
Purpose: The goal of the study is try to find the influence of plastic deformation using the RCS (repetitive corrugation and straightening) process on the structure and mechanical properties of CuSn6 alloy. The influence of process parameters on the above property were investigated. Obtained results were correlated with the results obtained for alloy subjected to cold rolling. Design/methodology/approach: This study was aimed to investigate structure and mechanical properties non annealed strip of CuSn6 alloy, cold-rolled and the tape subjected to intensive plastic deformation using the RCS method (repetitive corrugation and straightening). Findings: Research have shown increase compressive stresses and tensile strength in material after RCS process compared to classic rolled. Crystallite size measurement confirmed the presence of nano-scale structures in the studied materials after deformation by RCS process. The used method of plastic deformation is promising for development materials with improved properties. Research limitations/implications: The research was carried out on samples, not on final elements. Practical implications: Research is moving towards the development of the materials with finest microstructure, known as ultra-fine-grained materials with improved properties, compared to currently known materials. Originality/value: This paper presents the results of study of the structure and mechanical properties CuSn6 alloy deformed in the RCS (repetitive corrugation and straightening) process.
PL
W niniejszym artykule przedstawione zostały przykładowe zastosowania róznych mikroskopów optycznych w laboratoryjnych badaniach tworzyw sztucznych. Omawiane przykłady mają na celu zobrazowanie spectrum możliwości pomiarowych współczesnych mikroskopów, kamer i oprogramowania.
EN
This article presents the examples of the usage of various optical microscopes in laboaratory studies of plastics. These examples illustrate the spectrum of measurement capabilities of modern microscopes, cameras and sofware.
EN
The objective of this work was to prepare benzofuroxan derivatives as new, dense, potentially energetic materials and to investigate their properties, with the main focus being on 5,6-dinitrobenzofuroxan (5,6-DNBF). 5,6-DNBF was prepared by a 3-step reaction sequence: a) 1-azido-3-nitrobenzene was synthesized by diazotation of 3-nitroaniline with sodium nitrite and subsequent reaction with sodium azide in acetic/sulfuric mixed acids; b) it was nitrated with HNO3/H2SO4 to 1-azido-2,4,5-trinitrobenzene; c) thermal cyclization of the latter compound in a polar solvent gave the desired 5,6-DNBF (m.p. 177 °C). It was fully characterized by UV/VIS, FT-IR and NMR spectroscopy, mass spectrometry and single crystal X-ray diffraction. The density of the compound (X-ray) was found to be comparatively high (1.88 g/cm3), and to be superior to the previously known, isomeric energetic material ? 4,6-dinitrobenzofuroxan (4,6-DNBF) (1.76 g/cm3). Furthermore, the synthesis of some other benzofuroxan derivatives, potentially interesting as high energy, density materials (HEDMs), has been carried out. The densities of the compounds obtained were calculated using ACD Labs software (version 4.0). Based on the results obtained, it could be concluded that 5,6-DNBF is one of the densest nitro derivatives of the benzofuroxan series, comparable to CL-14, CL-17, CL-18, and thus could have potential applications as an HEDM.
17
Content available remote Specyfika konstrukcji hali widowiskowo-sportowej "Spodek" w Katowicach
EN
The paper presents the complex structure of the assembly and sports hall "Spodek" in Katowice. This edifice is founded on a site exposed to possible damages due to mining activities. Constructing this building, the so-called kinematic system of founding was applied, consisting in the upheaval of the spot footings checking the creeping of the soil, reducing in this way the effect of the curvature of the terrain on the deformation of the main foundation ring. Advanced procedures of calculations have been presented, which permitted to assess the actual effort of the most important carrying elements of the hall. The way of strengthening those elements, whose load-bearing capacity was insufficient, has been characterized.
18
Content available remote Modelowanie i analiza konstrukcji
PL
W referacie przestawiono wybrane zagadnienia modelowania i analizy konstrukcji w nawiązaniu do eurokodów konstrukcyjnych. Szczególną uwagę zwrócono na zagadnienia stanowiące nowe ujęcie w stosunku do dotychczasowych norm krajowych. W nawiązaniu do PN-EN 1990 przedstawiono ogólne zasady obliczania i projektowania zasadniczych układów nośnych szkieletowych konstrukcji budowlanych, uzupełniając je szczegółowymi regułami podanymi w PN-EN 1993-1-1 i PN-EN 1993-1-8 w odniesieniu do ustrojów projektowanych jako konstrukcje stalowe. Omówiono kryteria klasyfIkacji odnoszące się do ustrojów nośnych niestężonych, a także sztywno i podatnie stężonych, uwzględniając przy tym zagadnienie podatności węzłów. Omówiono zasady budowy imperfekcyjnych modeli obliczeniowych ustrojów nośnych i układów stężających konstrukcji, a także doboru metod analizy globalnej, w odniesieniu do wymagań w zakresie uwzględnienia zarówno nieliniowości geometrycznej (analizy I rzędu, II rzędu lub III rzędu), jak i nieliniowości fIzycznej (analiza sprężysta lub niesprężysta). Na zakończenie przedstawiono wykorzystanie zaawansowanej analizy konstrukcji do projektowania na podstawie ścieżki równowagi.
EN
Aspects of structural modelling and analysis according to Eurocodes are presented. It focuses on important, general topics that are required in design of steel structures. Categories of structures are dealt with that distinguish between the design situations of modelling the behaviour of wall and slab panels, taking into account their participation in the following: a) distribution of internal forces, b) restraining the frame elements in the out-of-plane direction, and c) transfer of loads onto the frame elements. Requirements with regard to certain methods of structural analysis to be used in design are summarized and related to situations met in practice. Aspects of the evaluation of imperfections impact on the performance of frameworks and bracing systems are also briefly presented. Finally, basic requirements for design using advanced analysis are summarized.
19
Content available Diagnostyka betonu na podstawie badania struktury
PL
Diagnostyka może dotyczyć różnych dziedzin, od biologicznego stanu zdrowia przez sytuację ekonomiczną lub społeczną aż do zagadnień technicznych, np. stanu konstrukcji czy maszyny. Przyjęto rozumieć znaczenie tego słowa jako identyfikację objawów i obecnego stanu przedmiotu zainteresowania oraz poznanie przyczyn i skutków tego stanu. W diagnostyce betonu można odróżniać różne przyczyny wad lub uszkodzeń: pochodzenia mechanicznego, np. w wyniku nadmiernego obciążenia, także lokalne skutki działań chemicznych (korozja, reakcja alkalia-kruszywo i in.) lub fizycznych, np. zmian termicznych, cykli zamrażania. Niektóre uszkodzenia mają źródło w procesach zachodzących w zaczynie cementowym lub w warstwie kontaktowej, a inne wynikają z warunków użytkowania konstrukcji. Diagnoza może obejmować także przewidywanie zakresu i rodzaju oddziaływania stwierdzonych defektów na dalsze zmiany właściwości betonu.
EN
The structure of concrete is analyzed from the view point of a diagnosis that should cover identification and estimation of possible damages and failures. High quality of concrete is essential in order to ensure adequate durability of a concrete structure. Various elements of the structure are described and the importance of its quantitative analysis is underlined. In a concrete the aggregate grains, pores, fibres, cracks and microcracks may be distinguished, i.e. their percentage volume and density, distribution and direction, origin and quality, as well as other features may be defined. For such aim usually the computer image analysis is applied. On the basis of a thorough structural analysis of the concrete it is possible to determine its quality, to check applicability of designed composition and to verify used components.
PL
Omówiono pracę konstrukcji nietypowej hali produkcyjnej. Analizę wykonano, wykorzystując zbudowany rnodel obliczeniowy, odzwierciedlający rzeczywisty charakter pracy w aktualnym stanie technicznym i konfiguracji obciążeniowej. Sprawdzono wymagania stanu granicznego nośności i użytkowaIności.
EN
The following paper presents behavior of untypical manufacturing room structure. The analysis was based on the detailed analytical model, which reflects the real character of structure behavior in current technical condition and load configuration. There were load capacity and serviceability limit states verified.
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