Wyniki wyszukiwania - BazTech

1

Determination of hydraulic fracturing pressure during drilling by an analytical method

Orujov Yusif A.

Nafta-Gaz

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2025

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R. 81, nr 5

355--358

EN

As well depth increases during drilling, the likelihood of various complications rises. These complications include drilling fluid loss, gas-oil-water influxes, wellbore stability issues, and pipe sticking. If appropriate preventive and corrective measures are not implemented, many of these complications may escalate into accidents. One such complication arising during well drilling is hydraulic fracturing of the formation. Hydraulic fracturing pressure is the pressure at which the integrity of the rock in the wellbore walls is compromised, leading to the formation of artificial fractures. Hydraulic fracturing during drilling is highly undesirable, as it results in the loss of drilling fluid into the surrounding formation. Hydraulic fracturing pressure depends on formation pressure, the natural fracturing of the rock, pore pressure, and the permeability of the rock and the fracturing fluid. As well depth increases, hydraulic fracturing pressure also increases and approaches formation pressure. Accurate determination of hydraulic fracturing pressure is therefore essential. The proposed method for determining a formation’s hydraulic fracturing pressure is economically advantageous. This research paper presents a method for determining hydraulic fracturing pressure based on the energy condition of destruction, taking into account the mechanical properties of the rock and formation pressure.

PL

Wraz ze wzrostem głębokości odwiertu wzrasta prawdopodobieństwo wystąpienia różnych komplikacji, takich jak ubytki płuczki wiertniczej, dopływy gazu, ropy lub wody, problemy ze stabilnością odwiertu oraz zakleszczenie przewodu wiertniczego. Brak wdrożenia odpowiednich środków zapobiegawczych i naprawczych może skutkować przerodzeniem się wielu z tych komplikacji w wypadki. Jedną z takich trudności pojawiających się podczas wiercenia otworów jest szczelinowanie hydrauliczne skały. Ciśnienie szczelinowania hydraulicznego to ciśnienie, przy którym dochodzi do osłabienia ciągłości skał w ścianach odwiertu, co prowadzi do powstawania sztucznych szczelin. Szczelinowanie hydrauliczne podczas wiercenia jest zjawiskiem wysoce niepożądanym, ponieważ powoduje wyciek płynu wiertniczego do otaczającej formacji. Ciśnienie szczelinowania hydraulicznego zależy od ciśnienia złożowego, obecności naturalnych spękań w skałach, ciśnienia porowego, przepuszczalności skały oraz rodzaju płynu szczelinującego. Wraz ze wzrostem głębokości odwiertu, ciśnienie szczelinowania hydraulicznego również wzrasta i zbliża się do ciśnienia złożowego. Dlatego tak istotne jest precyzyjne określenie ciśnienia szczelinowania hydraulicznego. Proponowana metoda wyznaczania ciśnienia szczelinowania hydraulicznego formacji jest korzystna ekonomicznie. W niniejszej pracy zaprezentowano metodę wyznaczania ciśnienia szczelinowania hydraulicznego w oparciu o kryterium energetyczne zniszczenia, uwzględniającą właściwości mechaniczne skały oraz ciśnienie złożowe.

2

Stress state of reinforced concrete walls of grain silos subjected to static and thermal actions – in situ tests and numerical analysis

Prusiel Jolanta Anna, Marynowicz Andrzej

Archives of Civil Engineering

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2025

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Vol. 71, nr 4

449--464

EN

In used reinforced concrete grain silos, failures occur (e.g., increased cracking of reinforced concrete walls). These failures may be caused by overloading of the chamber structure due to a sudden drop in ambient temperature throughout the day. These daily drops in ambient temperature cause thermal stresses in the silo shell. Additional thermal stresses in the silo are caused by the interaction of the wall and the bulk material stored within the silo. This results in additional tensile stresses in the cross-sections of the silo chamber wall, combined with bending. This paper presents the results of in situ studies of early winter temperature field distributions in a grain elevator at the Podlaskie Grain Plant in Białystok. A specialized prototype SensoNet telemetry system was used for the on-site tests, enabling continuous monitoring of operating silo batteries and recording physical quantities such as deformation and temperature. The measured variable temperature fields on the surface of the silo chambers were used to determine nonlinear temperature distributions across the thickness of the reinforced concrete walls in the grain silo battery using the finite difference method. Numerical calculations of four interlocking grain silos subjected to static (Janssen pressure of bulk material) and thermal loads were performed using the finite element method. Analysis of the numerical calculation results (FEM) demonstrates the unfavorable effects of thermal and static load coupling in the form of increases in latitudinal tensile stresses and bending moments in the reinforced concrete walls of the grain silo batteries.

PL

W eksploatowanych żelbetowych silosach na zboże występują stany awaryjne (np. zwiększone zarysowanie żelbetowych ścian), których przyczyną mogą być stany przeciążenia konstrukcji komór związane z gwałtownym spadkiem temperatury otoczenia w ciągu doby. Dobowe spadki temperatury otoczenia wywołują naprężenia termiczne w powłoce silosu. Występowanie dodatkowych naprężeń termicznych w silosie spowodowane jest interakcją ściany i ośrodka sypkiego składowanego w silosie. Efektem tego jest wystąpienie w przekrojach ściany komory silosu dodatkowych naprężeń rozciągających połączonych ze zginaniem. W pracy przedstawiono wyniki badań in situ w okresie wczesnozimowym rozkładów pól temperatury na elewatorze zbożowym w Podlaskich Zakładach Zbożowych w Białymstoku. Do badań na obiekcie wykorzystano specjalistyczny prototypowy system telemetryczny SensoNet umożliwiający ciągły monitoring eksploatowanych baterii silosów i rejestrację wielkości fizycznych, takich jak: odkształcenia i temperatura. Pomierzone zmienne pola temperatur na powierzchni komór silosowych posłużyły do wyznaczenia metodą różnic skończonych nieliniowych rozkładów temperatury na grubości żelbetowych ścian w baterii silosów na zboże. Przeprowadzono metodą elementów skończonych obliczenia numeryczne czterech silosów zblokowanych na zboże poddanych oddziaływaniom statycznym (parcie Janssena materiału sypkiego) i termicznym. Na podstawie analizy wyników obliczeń numerycznych (MES) przedstawiono niekorzystne efekty sprzężenia obciążeń termicznych i statycznych w postaci przyrostów rozciągających naprężeń równoleżnikowych i momentów zginających w żelbetowych ścianach baterii silosów na zboże.

3

Influence of Nonlinear Shear Modulus Change of Elastomeric Shell of a Composite Tractive Element with a Damaged Structure on its Stress State

Belmas Ivan, Kolosov Dmytro, Onyshchenko Serhii, Bilous Olena, Tantsura Hanna

Inżynieria Mineralna

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2023

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no. 1

147--154

EN

Purpose. Determination of a dependency of a stress state for composite elastomer-cable tractive element with a broken structure on a nonlinear dependency of shear modulus on deformations in the elastomeric shell. Methods. Analytical solution of a model of a composite tractive element with disturbed structure and a deformation-dependent shear modulus of an elastomeric shell. Findings. Algorithm for determining a stress state of a composite tractive element with broken structure and a deformation-dependent shear modulus. Scientific novelty. Character of dependency for a stress state of a composite tractive element on a nonlinear dependency of shear modulus on deformations. Practical significance. A possibility to determine the dependency of a stress state of a composite elastomer-cable tractive element on a nonlinear shear modulus. Scientific novelty. Character of dependency for a stress state of a composite tractive element on a nonlinear dependency of shear modulus on deformations. Practical significance. A possibility to determine the dependency of a stress state of a composite elastomer-cable tractive element on a nonlinear shear modulus allows considering the effect of this phenomenon on the tractive element strength and ensures an increase of its operational safety.

PL

Artykuł przedstawia studium i analizę funkcjonalną wymagań światowego przemysłu metalurgicznego co do jakości rud żelaza w podziemnych kopalniach Ukrainy. Stwierdzono zależności wpływu kształtu i parametrów przestrzeni kompensacyjnych na ich stateczność i wskaźniki jakości rudy. Udowodniono, że komora wyrównawcza w kształcie trapezu pionowego charakteryzuje się największą stabilnością i jest stabilna w zakresie wszystkich rozważanych głębokości, nawet w rudach o twardości 3–5 punktów. Mniejszą stateczność wykazuje komora kompensacji pionowej o kształcie sklepionym z niewielkimi spadkami w przyczółku sklepienia komory w rudach o twardości 3–5 punktów na głębokości 2000 m. Komora z opadami o rożnym natężeniu występuje w dolnej części nachylonych odsłonięć namiotu w rudach o twardości 3–5 punktów na głębokości 1750 m lub większej. Pomieszczenie kompensacji poziomej ma najmniejszą stateczność; spadki występują w rudach o twardości 3–5 punktów na głębokości 1400 m, a na głębokościach 1750–2000 m pozostają stabilne tylko w rudach twardszych. Stwierdzono, że zastosowanie komór kompensacyjnych o dużej stabilności umożliwia osiągnięcie ich maksymalnej objętości, zwiększenie ilości wydobywanej czystej rudy, zmniejszenie jej rozrzedzenia, poprawę jakości wydobywanej masy rudy, a co za tym idzie, wzrost jej ceny i konkurencyjności rynkowej.

4

Problematyka badań współczynnika filtracji w aparacie trójosiowego ściskania

Kaczmarek Łukasz, Dąbska Agnieszka, Popielski Paweł

Przegląd Geologiczny

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2022

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Vol. 70, nr 5

417--423

EN

Laboratory tests, which enable determination of the permeability properties of soil, are distinguished by the accuracy and relatively shorttesttime. Moreover, laboratory methods using a triaxial compression apparatus expand capability for tests with a different filtration regime and a spatial stress state applied on the analysed material. Such flexibility of research procedures allows for a number of scientific and engineering applications. The article outlines the construction of the triaxial apparatus system dedicated to filtration tests, their procedure, and important interpretation aspects.

5

Korzyści z zastąpienia kryteriów temperaturowych przez naprężeniowe dla zapewnienia bezpieczeństwa i dyspozycyjności bloków energetycznych eksploatowanych w trybie regulacyjnym oraz o zwiększonej elastyczności

Trzeszczyński Jerzy, Hatłas Marcin, Murzynowski Wojciech

Energetyka

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2022

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nr 6

307--310

PL

W artykule zaprezentowano podejście, w którym kryteria temperaturowe określone w formule Bloków Ograniczeń Termicznych (BOT) zastąpiono kryteriami naprężeniowymi generowanymi w Bloku Kontroli Trwałości (BKT). BKT na bieżąco analizuje m.in. stan naprężeń w elementach krytycznych bloku energetycznego wykorzystując ich cyfrowe bliźniaki. Podejście BKT pozwala na dokładniejsze odwzorowanie stanów termicznych i naprężeń. W stopniowo coraz bardziej zaawansowanej formie jest rozwijane w Pro Novum od wielu lat. Towarzyszy zwłaszcza rozwojowi systemów zdalnej diagnostyki jako nieodzownego narzędzia oceny stanu technicznego i prognozowania trwałości dla bloków i urządzeń eksploatowanych w coraz bardziej regulacyjnym trybie. BKT opracowano w ramach Programu Bloki 200+ i zaimplementowano na bloku referencyjnym nr 1 w ENEA Elektrownia Połaniec S.A.

EN

The article presents an approach in which the temperature criteria specified in the formula of Thermal Restriction Blocks (Pol. BOT) were replaced with stress criteria generated in the Life Control Block (Pol. BKT). BKT analyzes on an ongoing basis, inter alia, the state of stresses in the critical elements of a power unit using their digital twins. The BKT approach allows for more accurate mapping of thermal states and stresses. In a gradually more and more advanced form, it has been developed in Pro Novum for many years. In particular, it accompanies the development of remote diagnostics systems as an indispensable tool for assessing the technical condition and predicting durability for units and devices operated in an increasingly flexible mode. The Life Control Block was developed under the 'Program Bloki 200+' (Power Units 200+ Program) and implemented on the reference block no.1 at ENEA Elektrownia Potanieć S.A.

6

Influences of stress states and loading directions on the anisotropic fracture of magnesium alloy AZ31B sheet under tension-dominated forming conditions

Qian Lingyun, Xu Sinuo, Li Heng, Zhou Yuwei, Sun Chaoyang, Ma Tengyun

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e213, 2022

EN

The crystallographic textures of metal sheet induced by the rolling process cause its anisotropic fracture behavior via plasticity anisotropy. This research aimed to characterize the anisotropic fracture behavior of magnesium alloy AZ31B sheet during the conventional tension-dominated forming conditions. Four specimens with different shapes were designed to cover diverse stress states, and were respectively tension-tested to fracture along the rolling direction (RD), diagonal direction (DD), and transverse direction (TD) of rolled sheet. Almost all specimens failed in the shear fracture mode with slight necking localization. The distinct differences among load response, strain distribution as well fracture strain for three directions revealed the severe anisotropic fracture characteristic. To characterize the fracture anisotropy, the isotropic modified Mohr–Coulomb (MMC) fracture criterion was revised into an anisotropic one by considering the effect of loading direction. The updated unified fracture model together with the Yld2000-3d anisotropic yield function had better performances in describing load responses of tension tests for scaled modified compact-tension (SMCT) specimens under three loading directions, especially blindly predicting their crack locations. Three SMCT specimens all failed due to the tension-dominated stress state with the stress triaxiality higher than 1/3. As a comparison, the isotropic MMC model separately calibrated by tests along the RD, DD, and TD can only predict the fracture behavior of SMCT specimen in the corresponding loading direction, but it failed to judge the fracture features of other two directions.

7

Finite-element analysis of strengthening the subgrade on the basis of boring and mixing technology

Tiutkin Oleksii, Neduzha Larysa, Kalivoda M.

Transport Problems

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2021

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T. 16, z. 2

189--197

EN

One of the effective techniques to strengthen the subgrade is boring and mixing technology, which is based on the immersion of vertical elements – piles into the subgrade. This method of strengthening significantly affects the stress state of the track superstructure. Two options of the placement of strengthening elements are examined in this paper. To determine the influence of position of strengthening elements on the stress state of the track superstructure, appropriate finite-element models were created. The models fully reflect the geometric and deformation characteristics of a real subgrade, which is strengthened by piles. The calculated stress state of the track superstructure is shown and analyzed in this paper. The main contribution of the paper lies in optimization of the geometric parameters of the technology to reduce the stress state of the "track superstructure–subgrade–soil basement" system. The results show that the location of piles near the rails is more effective than the location of piles near the ballast section.

8

Experimental and Numerical Stress State Assesment in Refill Friction Stir Spot Welding Joints

Gadalińska Elżbieta, Kubit Andrzej, Trzepieciński Tomasz, Moneta Grzegorz

Fatigue of Aircraft Structures

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2021

|

Iss. 13

54--71

EN

Refill Friction Stir Spot Welding (RFSSW) is a technology used for joining solid materials that was developed in Germany in 2002 by GKSS-GmbH as a variant of the conventional friction stir spot welding (FSSW) [1]. In the RFSSW technology, the welding tool consists of a fixed outer part and rotating inner parts, which are called a pin and a sleeve. The tool for RFSSW is designed to plasticize the material of the parts to be joined by means of a rotary movement. The design of the tool allows independent vertical movement of both elements of the welding tool. This allows obtaining spot welds without creating holes that could weaken the structure. The main advantage of RFSSW is the potential for replacing the technologies that add weight to the structure or create discontinuities, such as joining with screws or rivets. Thus, RFSSW has great potential in the automotive, shipbuilding and aviation industries. Furthermore, the technology can be used to join different materials that could not be connected using other joining methods. The main objective of this work is to understand the physical and mechanical aspects of the RFSSW method - including the residual stress state inside the weld and around the joint. The results of the investigations can help to determine optimal parameters that could increase the strength and fatigue performance of the joint and to prove the significant advantage of RFSSW connections over other types of joints. The work assumes the correlation of two mutually complementary investigation methods: numerical analyses and experimental studies carried out with diffraction methods. The comparison between numerical and experimental results makes potentially possible the determination of degree of fatigue degradation of the material by observing the macroscopic stress state and the broadening of the diffraction peak width (FWHM), which is an indicator of the existence of micro-stress related to the dislocation density and grain size.

9

Diagnostics of the strength and stiffness of the loader carrier system structural elements in terms of thinning of walls by numerical methods

Orobey Viktor, Nemchuk Oleksii, Lymarenko Oleksandr, Piterska Varvara, Sherstiuk Olha, Romanov Oleksandr, Tkachuk Kateryna

Diagnostyka

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2021

|

Vol. 22, No. 3

73--81

EN

Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses.

10

Determination of stress state based on well logging data and laboratory easurements – a CBM well in the southeastern part of the Upper Silesian Coal Basin (Poland)

Kępiński Michał

Geology, Geophysics and Environment

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2020

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Vol. 46, no. 2

77--92

EN

The main objective of this study is to present calculation methods of horizontal stress profiles, taking into account the stress boundaries model, poro-elastic horizontal strain model and the effective stress ratio approach, using calibration with wellbore failure. The mechanical earth model (MEM) parameters from log measurements and well testing data were estimated for a well located in the southeastern part of the Upper Silesian Coal Basin. Log-derived horizontal stresses of the well are commonly treated as the final product of geomechanical modeling in oil and gas practices. A less popular method for estimating horizontal stresses is based on Kirsch equations juxtaposed with compressional and tensile failure observed on a micro-imager or six-arm caliper. Using this approach, horizontal stresses are determined based on the fact that when hoop stresses exceed the formation’s tensile strength, tensile fractures are created, and when those stresses exceed the compressive strength of the formation, breakouts can be identified. The advantage of this method is that it can be run without in situ stress measurements. The presented workflow is recommended every time there is an image log and dipole sonic measurement in the available dataset, both being necessary to observe the failure zones and MEM.

11

Modelling of impulse load influence on the stress state of foam materials with positive and negative poisson’s ratio

Sulym Heorhiy, Mikulich Olena, Shvabyuk Vasyl

Acta Mechanica et Automatica

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2020

|

Vol. 14, no. 2

79--83

EN

The influence of impulse load applied for different duration on the distribution of normalised dynamic radial stresses in positive and negative Poisson’s ratio medium was investigated in this study. For solving the non-stationary problem in the case of plane deformation for structurally inhomogeneous materials, the model of Cosserat continuum was applied. This model enables accounting for the influence of shear-rotation deformation of micro-particles of the medium. In the framework of Cosserat elasticity, on applying the Fourier transforms for time variable and developing the boundary integral equation method, solving of the non-stationary problem reduces to the system of singular integral equations, where the components that determine the influence of shear-rotation deformations are selected. The numerical calculations were performed for the foam medium with positive and negative Poisson’s ratio for different values of time duration of impulse. Developed approach can be used to predict the mechanical behaviour of foam auxetic materials obtained at different values of a volumetric compression ratio under the action of time variable load based on analysis of the dis-tribution of radial stresses in foam medium.

12

Stress state in the tapered beam bending : analytical and numerical FEM studies

Magnucki Krzysztof, Lewiński Jerzy, Stawecka Hanna

Pojazdy Szynowe

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2019

|

Nr 2

1--8

EN

The paper is devoted to comparative analysis of the stress state in bending of a tapered cantilever beam, calculated analytically and numerically (FEM). The analytical model is described based on bibliography, moreover, the numerical FEM model is developed with the use of the SolidWorks software. The results i.e. the stresses obtained by analytical and numerical calculation are compared and specified in Tables and Figures.

PL

Praca przestawia analizę porównawczą stanu naprężenia w zginanej belce wspornikowej o zmiennej wysokości. Przeprowadzono obliczenia analityczne i numeryczne metodąelementów skończonych. Model analityczny został opisany na podstawie literatury, na-tomiast model do obliczeń metodą elementów skończonych opracowano z zastosowaniem systemu SolidWorks. Wyniki, tzn. naprężenia wyznaczone analitycznie i numerycznie zostały porównane i zamieszczone w tablicach oraz zilustrowane na rysunkach.

13

Stress states caused in chamber of reinforced concrete grain silo by non-centric emptying on large eccentricities

Prusiel J. A., Gierej K.

Studia Geotechnica et Mechanica

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2018

|

Vol. 40, nr 4

282--291

EN

The article presents the analysis of complex stress states in the concrete structure of grain silos, caused by non-centric emptying. The authors present a combination of loads from the pressure of bulk solid on the silo chamber according to Eurocode 1, Part 4 [11], which should be taken into account when emptying on large eccentricities in action assessment class 3 (AAC3) silos. For the example of a cylindrical wheat silo with a height of 25 m and a diameter of 10 m, the researchers carried out an analysis regarding the impact of the size of the eccentric discharge outlet on the distributions of forces and bending moments in a reinforced concrete wall.

14

Ocena deformacji kwarcu w wybranych surowcach skalnych stosowanych do produkcji kruszyw łamanych do betonu w Polsce

Pabiś-Mazgaj Ewelina

Prace Instytutu Ceramiki i Materiałów Budowlanych

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2018

|

R. 11, nr 34

62--75

PL

Celem pracy było określenie stopnia deformacji kwarcu w wybranych surowcach skalnych stosowanych w produkcji kruszyw łamanych do betonu w Polsce. Kwarc o zdeformowanej strukturze, czyli kwarc w stanie naprężeń, zaliczany jest do składników mogących powodować szkodliwą reakcję alkalia–krzemionka (Alkali-Silica-Reaction – ASR) w betonie [3]. Ocena podatności na reakcję ASR odgrywa ważną rolę w wyborze kruszywa do betonu. W pracy do oceny stopnia deformacji struktury kwarcu wykorzystano analizę mikroskopową w świetle przechodzącym. Analizie poddano próbki surowców skalnych stosowanych do produkcji kruszyw łamanych do betonu z 5 zakładów eksploatacyjnych. W przypadku jednej próbki przeprowadzono obrazowanie transmisyjne (TEM). Obserwacje w mikroobszarach umożliwiły identyfikację anomalii optycznych oraz mikrostruktur kwarcu, charakterystycznych dla różnych stopni jego deformacji określonych według klasyfikacji zawartej w publikacji Tiechera i współautorów [5]. Wyniki badań wykazały, że w każdej z badanych próbek, poza próbką K1, identyfikowany był kwarc o różnych stopniach deformacji. Udział kwarcu wykazującego cechy odpowiadające poszczególnym stopniom deformacji struktury był różny w poszczególnych surowcach skalnych, co może mieć wpływ na kształtowanie ich podatności na reakcję alkalia–krzemionka.

EN

The aim of the research was to determine the deformation degree in quartz from particular rocks, which are being applied as crushed aggregates for concrete in Poland. Quartz with deformed structure, that is strained quartz, is determined as constituent which can cause nocuous alkali-silica reaction (ASR) in concrete [3]. Assessment of the susceptibility to alkali-silica reaction of quartz is crucial in the selection of the aggregates for concrete. In order to assess the deformation degree in quartz the optical microscopic analysis in transmitted light was conducted. The study involved the rock samples for crushed aggregate for concrete from 5 different quarries. In case of the one of the samples, the TEM analysis was applied. Examination under the microscope was applied to identify optical anomaly and microstructures related to particular deformation degrees of quartz determined according to the classification contained in the article by Tiecher et al. [4]. The results have indicated that in every sample, except for the K1 sample, the quartz crystals with different deformation degrees were identified. Quantity of the quartz grains featuring different degree of deformation varies in particular samples. That can affect their susceptibility to alkali-silica reaction.

15

Preliminary analysis of a rotary compression test

Pater Zbigniew, Walczuk Patrycja, Lis Konrad, Wójcik Łukasz

Advances in Science and Technology. Research Journal

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2018

|

Vol. 12, no. 2

77--82

EN

The paper addresses the problem of material fracture in cross rolling processes. A new test based on rotary compression for determining limit values of the damage function after the Cockroft-Latham criterion is proposed. A FEM analysis is performed to determine the stress and strain states in a workpiece subjected to this test. The numerical results demonstrate that the axial region of the workpiece is characterized by the presence of alternating tensile and compressive stresses conducive to fracture. The distribution of the Cockroft-Latham integral in the axial region of the workpiece is determined.

16

Stress state laboratory verification in masonry structures according to the flat jack method

Łątka D.

Technical Transactions

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2017

|

Vol. 2(114)

119--128

EN

In the article, the value of compressive stress defined according to the flat jack method with a theoretical value of the stress was compared. The test was performed in a laboratory using part of the 38 cm thick masonry wall according to the procedure described in the A STM C1196 – 14a Standard. Significant correspondence between the obtained results confirms that this diagnostic method is useful in Polish conditions as well as it allows one to estimate approximately how accurate it is.

PL

W artykule dokonano porównania wartości naprężenia ściskającego określonego według metody flat jack z wartością teoretyczną tego naprężenia. Test wykonano w laboratorium na fragmencie ściany murowej o grubości 38 cm według procedury opisanej w normie ASTM C1196 – 14a. Uzyskana duża zgodność wyników potwierdza przydatność metody diagnostycznej w warunkach polskich, jak również pozwala na orientacyjne oszacowanie jej dokładności.

17

Procedura badania PB01 stanu naprężenia w elementach stalowych z wykorzystaniem efektu Barkhausena

Augustyniak B.

Przegląd Spawalnictwa

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2017

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R. 89, nr 11

67--69

PL

Przedstawiamy syntetyczny opis pierwszej w Polsce procedury badania o nazwie PB01, która dotyczy badania stanu naprężenia w elementach stalowych z wykorzystaniem efektu Barkhausena. Procedura ta została opracowana przez firmę NNT sp. z o.o. i uzyskała uznanie przez Polski Rejestr Statków w styczniu 2017 r.

EN

There is presented synthetic description of the first in Poland test procedure labelled as PB01 which allows stress state evaluation in steel elements using Barkhausen effect. This test procedure was elaborated by NNT Ltd. company and had been approved by Polski Rejestr Statków in January 2017.

18

Modelling and simulation of core-shell precipitates under tensial loading using the cellular automata method

Staszczyk A., Debyser M., Sawicki J.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 3

443--452

EN

The equivalent truss method has been known for years as a numerical model used in problems with structural optimization. It is often implemented in computational algorithms based on cellular automation (CA). This method (CA) is highly versatile and allows the modelling of phenomena which occur in multiple dimensional scales, including material engineering issues. This paper describes a numerical model used to simulate the stress caused by the external load in a multi-phase material. The authors propose applying the algorithm in modelling the behavior of alloy materials following a thermal treatment which leads to precipitate hardening.

19

On the choice of thickness of the cement mantle in cemented hip arthroplasty

Levadnyi I., Awrejcewicz J., Loskutov A., Szymanowska O.

Journal of Theoretical and Applied Mechanics

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2017

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Vol. 55 nr 4

1235--1244

EN

Recommendations for the optimal thickness of the cement mantle in cemented hip arthroplasty are outlined based on the results obtained with the finite element method. The investigations show that distal femur cement thickness higher than 2 mm positively affects mechanical behaviour of the cement mantle and can be useful in reducing stress-strain levels in the distal part of the femur what leads to prevention of development of a stress-shielding effect. The results of the study can contribute to the success of long-term implants.

20

Use of 3D printing technology in the aviation industry on an example of numerical experimental stress state analysis of unmanned aerial vehicle wing

Święch Ł., Bendarz A.

Journal of KONES

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2017

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Vol. 24, No. 4

327--334

EN

The article presents the results of static tests performed on the primary support structures of a TWISST-ter unmanned aircraft constructed using additive manufacturing techniques commonly known as 3D printing. The primary goal of the experiment was determining the material effort of the structure in order to assess the feasibility of such an engineering solution in terms of material mechanics. Considering the fact that the properties of 3D printed elements are not widely known, both destructive experimental methods and finite element methods were used. During the experimental trails, the ARAMIS deformation measurement system, based on digital three-dimensional image correlation, was used. The results of this experiment allowed for the calibration of the numerical model as achieving convergence with experimentally determined strain fields. This approach ensured the correctness of the numerical determined stress state. Based on the results of the study, the necessary design improvements were implemented and a general conclusion was formed regarding of the numerical analysis of structures made through 3D printing.