Search results for: Indirect tensile fatigue
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Stress analysis of the bridge hangers in terms of the fatigue verification
PublicationThe paper presents the results of numerical stress analysis of the bridge rod hangers. Two types of hangers were taken into account, i.e. the bolted hanger and the welded hanger. A detailed FEM shell models of the connection area between the hanger and the bridge span have been developed. Local stress concentration effects have been investigated in terms of fatigue verification.
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An investigation on residual stress and fatigue life assessment of T-shape welded joints
PublicationThis paper aims to quantitatively evaluate the residual stress and fatigue life of T-type welded joints with a multi-pass weld in different direction. The main research objectives of the experimental test were to test the residual stress by changing direction along with multiple wielding passes and determine the fatigue life of the welded joints. The result shows that compressive residual stress increases in the sample gradually...
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Effect of bending-torsion on fracture and fatigue life for 18Ni300 steel specimens produced by SLM
PublicationIn this study, different fracture surfaces caused by fatigue failure were generated from 18Ni300 steel produced by selective laser melting (SLM). Hollow round bars with a transverse hole were tested under bending-torsion to investigate the crack initiation mechanisms and fatigue life. Next, the post-failure fracture surfaces were examined by optical profilometer and scanning electron microscope. The focus is placed on the relationship...
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Mechanical properties of Precontraint 1202 S2 based on uniaxial tensile and creep tests
PublicationThe purpose of the paper is the estimation of the polyvinyl chloride – polyester-coated fabric (Precontraint 1202 S2) mechanical properties under uniaxial tensile tests as well as short- and long-time creep tests. The uniaxial tests are the basis of non-linear elastic description while the creep tests are used for the evaluation of the stiffness parameters in time and for the identification of the standard viscoelastic model. The...
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Application a laboratory stand for multi-symptoms tests for high cyclic fatigue of constructional material
PublicationThis paper describes a need of diagnostics present ship plants according to current technical state. In order to reach competent physical quantity describing fatigue of materials by congregated energy. This paper describes using some diagnostics methods (acoustic emission AE, vibration, thermovision, deformation) in order to definition fatigue state of construction material. The author tries to find correlation between measured...
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Application of acoustic emission for detection of fatigue microdemage in main and crank bearings for diesel engines
PublicationThe article presents reasons for applying the acoustic emission (AE) to detect fatigue microdamage in main bearings and crank bearings of ship main engines. Problem of determination of the fatigue life for slide bearing bushes was characterized in general. There were demonstrated properties of the objects of research, which were bushings made of the MB58 alloy, as well as an overall description of the research. It was shown that...
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FE investigations of the effect of fluctuating local tensile strength on coupled energetic-statistical size effect in concrete beams
PublicationThe effect of fluctuating local tensile strength on a coupled energetic-statistical size effect in plain concrete beams under bending was numerically investigated. First, the influence of varying autocorrelation length of the random field describing a spatial variation of local tensile strength was studied. Next, the influence of the coefficient of variation of local tensile strength was analyzed. The numerical FE investigations...
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Antecedents and outcomes of social media fatigue
PublicationPurpose – This study aims to explore which of four chosen factors (i.e. privacy concerns, FoMO, self-disclosure and time cost) induce a feeling of strain among Facebook users in terms of social media fatigue (SMF), and if this occurs, whether it further influences such outcomes as discontinuance of usage (DoU) and interaction engagement decrement (IED). Design/methodology/approach – Through an online structured questionnaire, empirical...
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An image processing approach for fatigue crack identification in cellulose acetate replicas
PublicationThe cellulose acetate replication technique is an important method for studying material fatigue. However, extracting accurate information from pictures of cellulose replicas poses challenges because of distortions and numerous artifacts. This paper presents an image processing procedure for effective fatigue crack identification in plastic replicas. The approach employs thresholding, adaptive Gaussian thresholding, and Otsu binarization...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublicationThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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Laboratory fatigue assessment of large geocomposite-reinforced double-layered asphalt concrete beams
PublicationGeosynthetic reinforcement of asphalt layers has been used for several decades. Evaluation of the influence of these materials on pavement fatigue life is still ongoing, especially for new types of geocomposites. This paper presents the evaluation of fatigue performance of large asphalt concrete beams reinforced with a new type of composite in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions...
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Laboratory fatigue assessment of large geocomposite-reinforced double-layered asphalt concrete beams
PublicationGeosynthetic reinforcement of asphalt layers has been used for several decades. Evaluation of the influence of these materials on pavement fatigue life is still ongoing, especially for new types of geocomposites. This paper presents the evaluation of fatigue performance of large asphalt concrete beams reinforced with a new type of composite in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions...
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Fracture surface formation of notched 2017A-T4 aluminium alloy under bending fatigue
PublicationThe effect of cyclic loading on facture surface topology in notched components made by aluminium alloys is not completely clear. Fractogra-phy and fracture mechanics can help to understand this interdependency. This paper aims to study the distribution of the fracture surface roughness of notched 2017A-T4 aluminium alloy after bending fatigue using an optical focus-variation surface measurement technique by applying the fracture...
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Fracture Surface Topography Parameters for S235JR Steel Adhesive Joints After Fatigue Shear Testing
PublicationThis paper presents the experimental results of a study investigating the effect of holes and notches made on the overlap ends on the strength of adhesive joints. Single-lap joints made of S235JR steel sheets bonded with Araldite 2024-2 epoxy adhesive were tested. For comparative reasons, static shear strength tests and high-cycle fatigue strength tests were performed. Adhesive-filled joints having three holes, each with a diameter...
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Polyester sail technical woven fabric behaviour under uniaxial and biaxial tensile tests
PublicationThe paper is focused on the identification of mechanical properties of a sail technical woven fabric (yacht sailcloth polyester) style 480 AP with MTO (Medium Tempered Optimized) finish. The non-linear elastic behaviour of the fabric applied for sails is investigated under uniaxial and biaxial tensile tests. Comparison of non-linear elastic parameters with others polyester coated fabrics is made. This paper is intended to be an...
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Influence of Heat Treatment Temperature on Fatigue Toughness in Medium-Carbon High-Strength Steels
PublicationCurrent research has demonstrated that the tempering temperature affects the martensitic transformation of medium-carbon high-strength steels. This temperature plays an important role in the final microstructure, percentage ratios of martensite to ferrite phases and, consequently, in the mechanical properties and the fatigue response. So far, the relationship between the martensitic tempering temperature and the cyclic deformation...
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Fatigue Performance of Double-Layered Asphalt Concrete Beams Reinforced with New Type of Geocomposites
PublicationThe reinforcement of asphalt layers with geosynthetics has been used for several decades, but proper evaluation of the influence of these materials on pavement fatigue life is still a challenging task. The presented study investigates a novel approach to the reinforcement of asphalt layers using a new type of geogrid composite, in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions is bonded...
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Fatigue fracture morphology of AISI H13 steel obtained by additive manufacturing
PublicationThe paper focuses on researching the effect of fatigue loading on metallic structure, lifetime, and fracture surface topographies in AISI H13 steel specimens obtained by selective laser melting (SLM). The topography of the fracture surfaces was measured over their entire area, according to the entire total area method, with an optical three-dimensional surface measurement system. The fatigue results of the SLM 3D printed steel...
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Tensile validation tests with failure criteria comparison for various GFRP laminates
PublicationThe paper studies the mechanical properties of glass fibre reinforced polymers (GFRP) with various types and orientation of reinforcement. Analyzed specimens manufactured in the infusion process are made of polymer vinyl ester resin reinforced with glass fibres. Several samples were examined containing different plies and various fibres orientation [0, 90] or [+45, –45]. To assess the mechanical parameters of laminates, a series...
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The conception of energetic investigations of the multisymptom fatigue of the simple mechanical systems' constructional materials
PublicationThe article presents the basic assumptions of the research project aimed, as the main scientific purpose, an identification of the slow-changeable energy processes surrounding the high-cycle fatigue of constructional materials within the plain mechanical system, especially the marine one, for diagnostic purposes. There is foreseen an application of alternative diagnostic methods based on energetic observations of the multi-symptom,...
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Impact of Tensile and Compressive Stress on Classical and Acoustic Barkhausen Effects in Grain-Oriented Electrical Steel
PublicationIn this paper, we present the results of the investigation of impact of tensile and compressive stress on the classical Barkhausen effect, magnetoacoustic emission (MAE) signal properties, and B(H) hysteresis loops for grain-oriented (GO) electrical steel. Samples have been glued to a nonmagnetic steel bar and stressed within elastic range (±800 μdef) by means of four-point bending method. The samples were cut out in two directions...
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Prediction of the fatigue lifetime of PUR structural elements using a combined experimental-numerical approach
PublicationThis paper presents a method for estimating the fatigue life of polyurethane elastomeric components. A rubber replacement - polyurethane of hardness 80ShA commonly used in vibration damping systems, for example, in motor vehicle suspensions, was used for the study. A metal-rubber bushing component was selected for analysis, and numerical analysis was carried out along with a fatigue model proposal based on a modification of the...
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Fracture surface topography investigation and fatigue life assessment of notched austenitic steel specimens
PublicationThe objectives of this study were to investigate the fracture surface topography of X8CrNiS18-9 austenitic stainless-steel specimens for different loadings and notch radii and to supplement the knowledge about the fracture mechanisms for fatigue performance. Cases with three different values of the notch radius ρ and the stress amplitude σa were analysed. The fracture topographies were quantified by the areas over their entire...
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The effect of dehydration/rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties
PublicationBacterial nanocellulose (BNC) is a natural biomaterial with a wide range of biomedical applications. BNC contains 99 % of water which makes it too thick to be used as a bioimplant material. The aim of the work was to determine the effect of the BNC dehydration followed by rehydration on its mechanical and physicochemical properties, in the context of the use of BNC as bio-prostheses in the cardiovascular system. Dehydration involved the...
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Metallurgical characterization and high-temperature tensile failure of Inconel 617 alloy welded by GTAW and SMAW—a comparative study
PublicationTwo types of the weld joint of Inconel 617 alloy were produced using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes with ERNiCrCoMo-1 filler metal and ENiCrCoMo-1 electrode, respectively. The weld metal showed the segregation of the principle alloying elements like Mo and Cr along the inter-dendritic spaces, triggering the formation of secondary phases. The microstructure characterization of the...
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Fatigue-Biomedicine Health and Behavior
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Investigating the Effects of Geometrical Parameters of Re-Entrant Cells of Aluminum 7075-T651 Auxetic Structures on Fatigue Life
PublicationIn this study, the effects of two geometrical parameters of the re-entrant auxetic cells, namely, internal cell angle (θ) and H/L ratio in which H is the cell height, and L is the cell length, have been studied on the variations of Poisson’s ratio and fatigue life of Aluminum 7075-T6 auxetic structures. Five different values of both the H/L ratio and angle θ were selected. Numerical simulations and fatigue life predictions have...
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Stable indirect adaptive control based on discrete-time T-S fuzzy model
PublicationThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discrete-time T-S fuzzy input-output model is employed to approximate the unknown plant dynamics. The T-S fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...
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Stable indirect adaptive control based on discrete-time T-S fuzzy model
PublicationThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discrete-time T-S fuzzy input-output model is employed to approximate the unknown plant dynamics. The T-S fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...
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Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue
PublicationThis paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and...
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Cost Effective Corrosion and Fatigue Monitoring for Marine Transport Products
PublicationW artykule omówiono genezę i główne założenia projektu badawczego "Cost Effective Corrosion and Fatigue Monitoring for Transport Products'' o kryptonimie CORFAT, realizowanego w ramach VII Programu Ramowego Unii Europejskiej. Przedstawiono cele i metodykę badań, zalety nowej nowej metodyki monitorowania statków, zadania projektu, zalety i ograniczenia metody Emisji Akustycznej (EA), opis innych metod badań nieniszczących (NNDT)....
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Influence of laser processing of the low alloy medium carbon structural steel on the development of the fatigue crack
PublicationThe paper contains the results of the structural analysis, hardness tests and fatigue tests conducted for the medium carbon structural steel with low content of Cr and Ni after its processing with CO2 laser beam. Pre-cracks were made in the round compact tension (RCT) specimen used for fatigue test. Next, four paths, parallel to each other, were melted on both sides of the samples using a laser beam. The paths were perpendicular...
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Modelling the effect of composition on the tensile properties of concrete
PublicationRozdział omawia wyniki analizy mezoskopowej procesu pękania w betonie podczas zginania. Obliczenia wykonano na poziomie mezo wykorzystując model degradacji sztywności z nielokalnym osłabieniem. Zbadano wpływ właściwości kruszywa, stref przejściowych, nacięcia oraz długości charakterystycznej mikrostruktury na zachowanie sie betonu. Zaproponowano 2 metody określenia reprezentatywnego elementu objętościowego w betonie.
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Thermal Barrier as a technique of indirect heating and cooling for residential buildings
PublicationW artykule zaprezentowano koncept pośredniego ogrzewania i chłodzenia budynków mieszkalnych promieniowaniem słonecznym zwany barierą termiczną. System składa się z polipropylenowych rurek umieszczonych w ścianach zewnętrznych, w których znajduje się płyn. Koncept jest zastosowany do stabilizacji i redukcji przepływu ciepła w kierunku prostopadłym do ścian. Wykonano obszerne obliczenia MES z zastosowaniem nowego systemu kontroli,...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Fatigue resistance investigation of the IC engine MB11 bearings, working under conditions of dynamic unidirectional loadings
PublicationThe slide bearing material MB11 fatigue resistance has been investigated with the application of SMOK - test stand in which dynamic unidirectional loadings to the test bearing is generated. Slide bearing layer consists of the bronze MB11 ( Cu Pb22 Sn 3 ) sintered to the steel shell. Each of the tested bearing has been subject to the standard 20-hour test, under conditions of the full fluid lubrication. Methodology of the experiments,...
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Analysis of effect of overloaded vehicles on fatigue life of flexible pavements based on weigh in motion (WIM) data
PublicationOverloaded vehicles have a significant impact on pavement fatigue life and distress. As the studies show, the phenomena intensify when the control of traffic is poor. The paper presents the results of the research including analysis of weigh in motion data from eight stations and analysis of asphalt pavement fatigue caused by mixed traffic. Distributions of vehicles axles load including the multiple axles effects are presented....
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PA32 aluminum alloy - tensile properties
Open Research DataIn addition to steel, aluminium alloys are the main building material used in the shipbuilding industry. Due to its undoubted advantages, such as low density (nearly three times lower than in the case of steel for shipbuilding) and high corrosion resistance, it is often used for hulls of yachts and small vessels as well as superstructures. For safety...
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Strucutral steel - tensile test results
Open Research DataModern floating structures such as ships, oil platforms and offshore wind towers are built mostly of structural steel. It is a material that is subject to requirements which, when met, allows the construction and safe operation of the structure throughout its entire work cycle. One of the basic criteria that a material must meet is its strength. The...
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Tensile failure study of 3D printed PLA using DIC technique and FEM analysis
PublicationThe paper presents the experimental and numerical study of the failure behaviour of Fused Filament Fabricated (FFF) Polylactic Acid (PLA) samples subjected to tensile load. The examined samples are printed in flat orientation with 0◦, 45◦ and 90◦ raster angles. During the experiments the deformation of the specimens is continuously scanned with the 3D Aramis measuring system utilizing the digital imaging correlation technique,...
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The energy approach to fatigue crack growth of S355 steel welded specimens subjected to bending
PublicationThe study presents the results of the research on the rate of fatigue crack growth subjected to bending in the ferritic-pearlitic structure. The studies were carried out at a constant amplitude of the moment and at various values of the load ratios R and at the operating frequency of the machine of 28.4 Hz. Flat specimens made of S355 steel and with fillet welds and with double-sided blunt external notches as well as concave...
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Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test
PublicationThermal stresses are leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when the temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature...
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Experimental research on over-laminated steel sandwich panel connection to determine the form of fatigue failure
PublicationThe novel means of transport need to meet rising both the economic and ecologic requirements. In recent years the International Maritime Organization (IMO) introduced new measure of ship energy efficiency (the EEDI index), as well as new regulations regarding higher quality of fuel (so called Tier limits). It resulted in much higher interest of the technological development of ships. One of the solution having great potential is...
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High-Temperature Tensile Behaviour of GTAW Joints of P92 Steel and Alloy 617 for Two Different Fillers
PublicationThis study explores the high-temperature (HT) tensile rupture characteristics of a dissimilar gas-tungsten-arc-welded (GTAW) joint between P92 steel and Alloy 617, fabricated using ER62SB9 and ERNiCrCoMo-1 fillers. The high-temperature tensile tests were performed at elevated temperatures of 550 ◦C and 650 ◦C. An optical microscope (OM) and a field emission scanning electron microscope (FESEM) were utilized to characterize the...
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Fatigue fracture surface metrology of thin-walled tubular austenitic steel specimens after asynchronous loadings
PublicationThis paper aims to study the effect of asynchronous axial-torsional strain-controlled loading histories on fracture surface behavior of thin-walled tubular X5CrNi18-10 (304/304L) austenitic steel specimens. Tests under pure axial loading and pure torsional loading are also conducted to better segregate the effect of multiaxiality. The fractures surface topographies were examined through the profiles over the entire surface with...
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On the use of uniaxial one-parameter damage laws for estimating fatigue life under multiaxial loading
PublicationThe goal of this paper is to evaluate the capabilities of different one-parameter fatigue laws to estimate crack initiation in notched components under multiaxial loading. Fatigue damage is accounted for through stress-based, strain-based, and energy-based approaches while the cyclic plasticity at the notch-controlled process zone is estimated using linear-elastic simulations. The results show that energy-based formulations established...
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Fatigue of the ship structure.
PublicationZaprezentowano wyniki prac badawczych zachowania paneli SANDWICH pod obciążeniem zginającym. Prace prowadzone były w Kat. Technol. Okrętów i Obiektów Oceanotechn. Wydz. OiO i obejmowały między innymi badania konstrukcji w skali rzeczywistej. Dokonano porównania uzyskanych rezultatów z wynikami prezentowanymi w literaturze.
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Novel fast analytical method for indirect determination of MCPD fatty acid esters in edible oils and fats based on simultaneous extraction and derivatization
PublicationA novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatisation in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of released from esterified forms analytes from water phase and dilution solvent for solid PBA – derivatisation agent. It is a noteworthy...
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The impact of surface slope and calculation resolution on the fractal dimension for fractures of steels after bending-torsion fatigue
PublicationThe article presents the results of the fractal dimension measurements on the fatigue fracture surfaces of 10HNAP and S355J2 steels specimens after combined bending-torsion fatigue. For smooth and ring-notched specimens, three loading conditions were analyzed: (1) bending; (2) bending-torsion; and (3) torsion fatigue. Post-failure surface topography measurements were carried out on the entire fracture surfaces using an optical...
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublicationIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...