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EN
In this paper, as a purpose to apply the supersaturated solid-solutionized Al-9Mg alloy to the structural sheet parts of automotive, tensile tests were conducted under the various conditions and a constitutive equation was derived from the tensile test results. Al-9Mg alloy was produced using a special mg master alloy containing Al2Ca during the casting process and extruded into the sheet. in order to study the deformation behavior of Al-9Mg alloy in warm temperature forming environments, tensile tests were conducted under the temperature of 373 K-573 K and the strain rate of 0.001/s~0.1/s. in addition, by using the raw data obtained from tensile tests, a constitutive equation of the Al-9Mg alloy was derived for predicting the optimized condition of the hot stamping process. Al-9Mg alloy showed uncommon deformation behavior at the 373 K and 473 K temperature conditions. The calculated curves from the constitutive equation well-matched with the measured curves from the experiments particularly under the low temperature and high strain rate conditions.
EN
This study is to find the extent of variation in mechanical properties between plate and pipe welds fabricated out of the same FSW process parameters. Common thickness of 3 mm along with similar tool specifications is used to fabricate the weld. Process parameters of tool rotational speed 2000 rpm and weld speed 94 mm/min that was defined as optimal for pipe weld is used as common process parameters. Welds are analyzed for hardness and tensile properties. Yield strength and ultimate tensile strength varied about 8.1% and 11.2% respectively between plate and pipe welds. The hardness of the stir zones varied about 11.6% between plate and pipe welds.
EN
In the recent years, additive manufacturing became an interesting topic in many fields due to the ease of manufacturing complex objects. However, it is impossible to determine the mechanical properties of any additive manufacturing parts without testing them. In this work, the mechanical properties with focus on ultimate tensile strength and modulus of elasticity of 3D printed acrylonitrile butadiene styrene (ABS) specimens were investigated. The tensile tests were carried using Zwick Z005 loading machine with a capacity of 5KN according to the American Society for Testing and Materials (ASTM) D638 standard test methods for tensile properties of plastics. The aim of this study is to investigate the influence of printing direction on the mechanical properties of the printed specimens. Thus, for each printing direction ( and ), five specimens were printed. Tensile testing of the 3D printed ABS specimens showed that the printing direction made the strongest specimen at an ultimate tensile strength of 22 MPa while at printing direction it showed 12 MPa. No influence on the modulus of elasticity was noticed. The experimental results are presented in the manuscript.
EN
In the present research, a physical-geometric-feature of continuous yarn in a plain woven fabric was created and its FE model was analysed by considering the two key issues of woven fabric, the crimp and inter-yarn friction. The basic parameters of Young’s modulus of single yarn and the inter-yarn friction coefficient were investigated for practical fabrics in tensile and pull-out tests. FE analysis indicated that the stress-strain curves of the FE model were effective in evaluating the equivalent modulus of a woven fabric by comparing with a tensile experiment on Twaron CT® Plain Woven Fabric. In addition, a simplified three dimensional model of the unit cell of plain woven fabric (UCPW) was employed to quantitively investigate two important fabric characteristics – the crimp rate of the yarn and inter-yarn friction-to determine their influence on the mechanical properties of the fabrics. Furthermore, we used FE analysis to evaluate how the crimp rate and inter-yarn friction affected the mechanical properties by determining the equivalent modulus of single yarn and UCPW in both uniaxial and biaxial tensile loading. The stresses at representative nodal points and the mechanical interaction between yarns were also investigated from a microscopic perspective, and their deformation mechanisms were also analysed and discussed.
PL
W pracy stworzono fizyczno-geometryczną cechę przędzy ciągłej w gładkiej tkaninie i przeanalizowano jej model FE, biorąc pod uwagę dwa kluczowe zagadnienia tkaniny: karbikowatość i tarcie między przędzami. Zbadano podstawowe parametry: moduł Younga przędzy pojedynczej oraz współczynnik tarcia między przędzami. Analiza FE wykazała, że krzywe naprężenie-odkształcenie modelu FE były przydatne w ocenie tkaniny przez porównanie z eksperymentem rozciągania tkaniny Twaron CT® Plain Woven. Ponadto zastosowano uproszczony trójwymiarowy model komórki elementarnej z gładkiej tkaniny (UCPW) do ilościowego zbadania dwóch ważnych cech tkaniny: szybkości fałdowania przędzy i tarcia między przędzami – w celu określenia ich wpływu na właściwości mechaniczne tkaniny. Ponadto wykorzystano analizę FE, aby ocenić, w jaki sposób szybkość fałdowania i tarcie między przędzami wpłynęły na właściwości mechaniczne. Dokonano tego poprzez określenie równoważnego modułu pojedynczej przędzy i UCPW zarówno przy jednoosiowym, jak i dwuosiowym obciążeniu rozciągającym. Naprężenia w reprezentatywnych punktach węzłowych i mechaniczne interakcje między przędzami zbadano również z perspektywy mikroskopowej, a także przeanalizowano i omówiono ich mechanizmy deformacji.
EN
Orthodontic wires are components of fixed appliances used to perform the necessary tooth movements in the course of the orthodontic treatment. A variety of materials e.g. metals, alloys, polymers and composites are used to produce orthodontic wires. This study examined the mechanical strength and cracks resistance of three different types of wires, i.e. made of: austenitic steel grade AISI 303, NiTi alloy and Tiβ alloy. Corrosion processes are regarded to have a harmful effect on the properties of orthodontic wires, such as their strength, biocompatibility and aesthetic appearance. In this study, we investigated the corrosive behaviour of the wires in the artificial saliva solutions with varied pH simulating the natural oral cavity environment. It was demonstrated that the orthodontic rectangular wires made of austenitic steel grade AISI 303 exhibited the highest tensile strength. The NiTi alloy wires exhibited the best plastic properties of all the examined samples. In the case of electrochemical tests (changes in corrosion potential over a period of 24 h), the wire made of austenitic steel and the NiTi alloy wire reached a stable level of the stationary potential in the acidic environment. For the wires made of Tiβ, the highest stationary potential was observed in the alkaline environment. Additionally, the Tiβ alloy wire revealed the broadest passivation area in the specified potential scope.
PL
W artykule przedstawiono realizację badań wytrzymałościowych nowego rodzaju uchwytów transportowych do prefabrykatów betonowych, które skonstruowano z nieużytecznych odpadów produkcyjnych stalowych lin sprężających. Omówiono uzyskane wyniki badań oraz podano zalecenia dotyczące warunków stosowania uchwytów.
EN
The article presents the course of tensile tests of a new type of transport handles for precast concrete elements, which were made from useless of production waste from steel prestressing strands. The test results have been discussed and recommendations regarding the conditions of using such handles have been given.
EN
Hydrostatic cyclic extrusion–compression as a novel severe plastic deformation method in the processing of the rods is introduced and used for refining ultrafine-grained commercial pure aluminum. HCEC is solving the limitation of the conventional CEC in producing long-length samples by utilizing pressurized hydraulic fluid and eliminating the frictional effects. An increase in the length of the processable sample, a reduction in the processing loads, an intensification in the hydrostatic stress, and improvement in the strain distribution are the novel achievements of the HCEC. The capability of HCEC in grain refinement of the commercial pure aluminum was investigated by transmission electron microscopy analysis. The processed samples showed the grain sizes of 780 nm and 400 nm after the first and second passes of the HCEC, respectively. Furthermore, tensile and shear punch tests were utilized for investigation of the mechanical properties of the unprocessed and HCEC processed rods. An increase in the tensile and shear yield and ultimate strengths after the process confirmed the decreases in grain sizes. The tensile yield and ultimate strengths of the rod after the second cycle of the process reached 170 and 196 MPa, respectively. The same increasing trend as strength was shown in the microhardness after the HCEC. FEM analysis depicted the homogenous distribution of strain along the length of the sample. Also, the independency of the processing force to the length of the sample was shown by the FEM. The implementation of this novel technique looks very interesting for the industrial utilization of SPD techniques, especially in automotive and aerospace industries, which suffer from the limited size of the processing specimens.
8
EN
Masonry was the most used material during the last centuries to build constructions. Most of the existing masonry structures (buildings, bridges, etc.) were built without considering some important structural considerations that are important nowadays. Moreover, due to factors such as the increasing of service loads, materials aging, structural damage, etc., the existing masonry structures require strengthening interventions. The definition of optimal strengthening strategies using traditional and innovative materials is still an important issue of the scientific research. In fact, during the last decade, many researchers focused their attention studying innovative composites materials, such as fiber-reinforced polymers and fiber-reinforced cementitious matrix composites, for the strengthening of existing masonry structures. This research has focused on aspects such as the bond behavior between the substrate and the composite materials, the structural behavior of the strengthened masonry and concrete structures, and the compatibility and reversibility of these materials when bonded to existing substrates. In this study, the bond behavior of a composite material known as steel fiber-reinforced mortar (SFRM), recently used as for the strengthening of existing structures, applied onto masonry structures is analyzed experimentally and numerically. First, the material is characterized experimentally with the aim of getting insight on its behavior and applicability when applied as an innovative technique for the strengthening of masonry and to obtain mechanical parameters required for the numerical models. Mechanical properties of the SFRM studied included flexural and compressive strength, tensile strength, and residual flexural strength. The SFRM bond behavior on masonry substrates was evaluated by means of double shear lap tests. In addition, the experimental tensile and bond behavior of the SFRM is studied numerically through finite-element models validated using the results obtained during the experimental tests. Results show that if an adequate bonded length is provided, the SFRM can fully develop its tensile strength as detachment from the substrate is not observed.
EN
In the present paper, computed tomography (CT) inspection is shown. The CT inspection method allowed to rate the density of defects hidden inside a material, which has a significant role in the live material. The method allows to evaluate the reliability of tensile test’s results. In our analysis, the position of crack propagation was determined by CT, and the tensile test was performed to check the accuracy of the nondestructive method. The tensile tests were performed on Inconel 738LC [1] samples.
EN
Additive manufacturing has recently expanded its potential with the development of selective laser melting (SLM) of metallic powders. This study investigates the relation between the mechanical properties and the microstructure of Ti6Al4V alloy produced by SLM followed by a hot isostatic pressing (HIP) treatment. HIP treatment minimizes the detrimental influence of material defects. Tensile specimens produced with reference to specific building axes were prepared using a Renishaw A250 system. It has been found that the tensile strength and elongation depend on specimen building direction. Microstructural and textural characterizations were carried out to identify the source of differences.
EN
The paper is focused on study of plasticity and formability of dual phase steel DP 450, which is used in automotive industry. The paper shows results from tensile test for plasticity determination and also results of technological tests for complex evaluation of formability. These consisted from Erichsen cup test, Fukui test and Schmidt test. The paper shows also results of microhardness measurement.
PL
Artykuł koncentruje się na badaniu plastyczności i odkształcalności stali dwufazowej DP 450, która jest stosowana w przemyśle motoryzacyjnym. W pracy przedstawiono wyniki prób rozciągania dla określenia plastyczności, a także wyniki testów technologicznych dla kompleksowej oceny odkształcalności. Składały się one z testu pucharowego Erichsena, testu Fukui i testu Schmidta. W pracy przedstawiono również wyniki pomiaru mikrotwardości.
EN
The presented research deals with the development of the numerical model for resins used for stereolithography (SLA) rapid prototyping. SLA is an additive method of production of models, prototypes, elements or parts of constructions with the use of 3D printing that covers photochemical processes by which light causes chemical monomers to link together to form polymers. Such method is very useful in design visualization, but also can be applied in numerical modelling for the purpose of validation and verifi-cation. In this application the resin strength parameters must be described and on the base of them the numerical material model is developed and validated. Such a study for SLA resins was presented in the paper.
EN
The aim of the study was the estimation of the ability of hyperelastic material models for the fitting of experimental data obtained in the tensile testing of silicone liners used in lower-limb prosthetics. Three groups of liners were analysed: I – silicone liner, II – part of the liner in which the silicone has a fabric reinforcement, III – silicone liner with an outer covering material. Both longitudinal and circumferential samples were taken. The Neo-Hookean, Mooney-Rivlin and Ogden parameters of constitutive models of hyperelastic materials were calculated.
PL
Celem badań była ocena przydatności modeli materiałów hipersprężystych do dopasowania danych doświadczalnych uzyskanych w próbie rozciągania dla silikonowych linerów ortopedycznych stosowanych w protezach dolnych. Przeanalizowano trzy grupy: I – liner silikonowy, II – liner silikonowy z wewnętrznym wzmocnieniem, III – liner silikonowy z zewnętrznym wzmocnieniem. Wyróżniono dwa kierunki pobrania próbek: podłużny i obwodowy. Zidentyfikowano parametry określonych funkcji modeli konstytutywnych materiałów hipersprężystych: Neo-Hookean’a, Mooney-Rivlin’a i Ogden’a.
PL
Duże zapotrzebowanie na odkuwki w postaci pierścieni dla różnych gałęzi przemysłu wymaga stosowania nowoczesnych stali martenzytycznych o właściwościach mechanicznych dostosowanych do konkretnego zastosowania. Aby sprostać wymaganiom rynku, powstała koncepcja projektu niskoodpadowej technologii kształtowania wielkogabarytowych pierścieni ze stali X20Cr13 i X10CrMoVNb9-1 o profilowanych pobocznicach. Liderem projektu jest firma Zarmen FPA. Jednym z etapów tego projektu jest opracowanie technologii obróbki cieplnej pierścieni. Wykonano badania mikrostruktury i właściwości mechanicznych (wg norm PN-EN ISO 6892-1:2016-09, PN-EN ISO 148-1:2017-02 i PN-EN ISO 6507-1:2007) na próbkach pobranych z odkuwek kutych swobodnie przy temperaturze 1110±20°C z redukcją wysokości materiału wsadowego 50% oraz obrobionych cieplnie w 2 wariantach: hartowanie stali X20Cr13 z temperatury 1020±10°C w oleju oraz odpuszczanie przy temperaturze 600°C i 700°C, hartowanie stali X10CrMoVNb9-1 z temperatury 1050±10°C w oleju oraz odpuszczanie przy temperaturze 650°C i 700°C. Materiałem wsadowym były wałki ϕ40x60 mm. Wykonano też badania porównawcze na próbkach pobranych z wałków w stanie dostawy hutniczej i poddanych obróbce cieplnej w tych samych warunkach co odkuwki. Wskaźniki Rp0,2 i Rm, zgodne z założeniami, otrzymano dla obu stali po odpuszczaniu próbek pobranych z odkuwek przy temperaturze 700°C, wynoszące odpowiednio: 660 MPa i 844 MPa dla stali X20Cr13 oraz 764 MPa i 893 MPa dla stali X10CrMoVNb9-1. Wydłużenie próbek z obu stali wyniosło 21%, a praca łamania KV2: 25 J dla stali X20Cr13 i 38 J dla stali X10CrMoVNb9-1. Planowana jest weryfikacja właściwości mechanicznych uzyskanych na próbkach pobranych z kutych wałków oraz z eksperymentalnie walcowanych pierścieni.
EN
The large demand for forgings in the form of rings for various branches of industry requires the application of modern martensitic steels with mechanical properties adapted to the specific application. To meet the requirements of the market, the first concept of low-waste forming technology for large-size rings made of X20Cr13 and X10CrMoVNb9-1 steel, with profiled side surfaces, was created. The leader of the project is Zarmen FPA. One of the stages of this project is the development of ring heat treatment technology. Tests of microstructure and mechanical properties (according to standards PN-EN ISO 68921:2016-09, PN-EN ISO 148-1:2017-02 and PN-EN ISO 6507-1:2007) were performed on samples collected from flat-die forgings at temperature 1110±20°C with 50% height reduction of the stock material and heat treatment in 2 variants: hardening of X20Cr13 steel from temperature 1020±10°C in oil and tempering at temperature 600°C and 700°C, hardening of X10CrMoVNb9-1 steel from temperature 1050±10°C in oil and tempering at temperature 650°C and 700°C. The stock material was ϕ40x60 mm shafts. Comparative tests were also performed on samples collected from shafts in the state as delivered from the mill and subjected to heat treatment under the same conditions as forgings. Indicators Rp0.2 and Rm, according to assumptions, were obtained for both steels after tempering of samples collected from forgings at temperature 700°C, and were equal to, respectively: 660 MPa and 844 MPa for X20Cr13 steel and 764 MPa and 893 MPa for X10CrMoVNb9-1 steel. Elongation of samples for both steels was 21%, and energy absorbed during fracture KV2: 25 J for X20Cr13 steel and 38 J for X10CrMoVNb9-1 steel. It is planned to verify mechanical properties obtained in samples collected from forged shafts and from experimentally rolled rings.
EN
3D polymer-based printers have become easily accessible to the public. Usually, the technology used by these 3D printers is Fused Deposition Modelling (FDM). The majority of these 3D printers mainly use acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) to fabricate 3D objects. In order for the printed parts to be useful for specific applications, the mechanical properties of the printed parts must be known. The aim of this study is to determine the tensile strength and elastic modulus of printed materials in polylactic acid (PLA) according to three important printing parameters such as deposition angle, extruder temperature and printing speed. The central composite design (CCD) was used to reduce the number of tensile test experiments. The obtained results show that the mechanical properties of printed parts depend on printing parameters. Empirical models relating response and process parameters are developed. The analysis of variance (ANOVA) was used to test the validity of models relating response and printing parameters. The optimal printing parameters are determined for the desired mechanical properties.
EN
Glass fibre reinforced composites are used in many branches of industry. Polyester-glass laminates serve as structural material in shipbuilding (e.g. hulls of units, superstructures), in railways, automotive (e.g. elements of car bodies and interior fittings, roofs of wagons, cisterns) or aviation (e.g. aircraft fuselages, fuel tanks, completion beaks and ballasts). Factors affecting the increase of their use include low specific gravity, optimal strength properties, corrosion resistance. This is associated with a large amount of post-production and post-use waste. The recycling problem of these materials remains unresolved. The article presents the technology of processing polyester-glass waste in order to obtain a recycle with a specific granulation. The selected technology for the production of layered composites with reinforcement in the form of recycle is described. For testing, granulation was selected for 1.2 and 3 mm, as well as content: 0%, 10%, 20% and 30%. Using the water-cutting method, samples were prepared according to the standard static tensile test for plastics. The tests were carried out using a universal testing machine as well as an extensometer for samples with granulation of 1.2 mm and 3 mm, as well as the selected recycled percentage. Obtained results of the research indicated that granulation as well as content affects the strength properties of composites. As the granulation increases, at the same content, the material gains less deformation. The increase in the amount of the recycle reduces the strength properties of the material, and also due to the decrease in the deformation value - the material becomes brittle.
EN
Composites are materials used for various types of constructions in the automotive industry, aviation, and shipbuilding. Due to the wide use of these materials, there is a problem with their recycling. Such material requires appropriate processing technology, which has been developed to obtain a recyclate with a specific granulation. The use of hand laminating technology made composites with the addition of polyester and glass recyclate with granulation of 1.2, as well as content: 0%, 20%, 30%. These types of materials are exposed to various types of atmospheric factors that affect their durability. Aging is defined as changes in the composite when exposed to atmospheric conditions, such as sunlight, temperature, thermal cycles, water in various forms and wind. This article uses recycled polyester and glass composites to investigate the effect of aging in seawater on their strength properties. These tests can be used to pre-assess the applicability of newly developed materials as construction or protective coatings. They were carried out on a specially prepared station for accelerated tests, with elevated temperature (35ºCC), as well as brine spray imitating sea atmosphere. The method is used to accelerate the aging processes occurring in composite materials. Samples were subjected to cycles of 5, 30 and 60 days respectively. Samples were weighed and measured before and after each cycle. In order to investigate the effect of aging on strength properties, the composites underwent a static tensile test in accordance with the standard for plastics. Studies have shown that as a result of the aging process, the strength properties decrease slightly, which affects the favourable assessment of these materials as constructional.
EN
This paper focused on the effect of pure torsion deformation and various torsion pitches on the mechanical properties of the commercial pure Al wires which has not been examined so far. The initial wires with diameter of 4 mm have been torsion deformed to different pitch length (PL). In order to investigate the effect of gradient microstructure caused by torsion deformation, three different pitch length of 15 mm, 20 mm and 30 mm are considered. The results revealed that the level of grain refinement is correlated with the amount of induced plastic shear strain by torsion deformation. For the wire with pitch length of 15 mm, the grain sizes decreased to about 106 μm and 47 μm in the wire center and edge from the initial size of about 150 μm of the annealed wire. The micro-hardness measurement results show a gradient distribution of hardness from the wire center to the wire surface that confirmed the increasing trend of plastic shear strain obtained by FE simulations. The hardness of annealed sample (35 HV) is increased up to 73 HV at the wire surface for the smallest pitch length. The yield and ultimate tensile strength of the torsion deformed wires are also increased up to about 85 MPa and 152 MPa from the initial values of 38 MPa and 103 MPa of the annealed one respectively while the maximum elongation reduced significantly.
EN
This work is focused on the effect of rolling with cyclic movement of rolls (RCMR) on microstructure, mechanical properties and electrical conductivity of CuCr0.6 and CuFe2 alloys in states after applying different heat treatments. The mechanical properties were determined by using MST QTest/10 machine equipped with digital image correlation (DIC). Scanning transmission electron microscopy (STEM) was used for microstructural characterization. The RCMR processed alloys shows high mechanical strength (UTS:539 MPa for CuCr0.6 alloy and UTS:393 MPa for CuFe2 alloy) attributed to the high density of coherent precipitates (after aging at 500 °C/2 h) and ultrafine grained structure. Plastically properties as uniform elongation (Agt) was about (∼1%) for both alloys after RCMR deformation. The RCMR processing induces a significant reduction of the electrical conductivity for samples, which were quenched before deformation, but for samples which were subjected to aging before deformation, the electrical conductivity was restored thanks to precipitation process.
EN
Nowadays, there are several reasons for the utilization of the sheets made of aluminum in the car body production. Besides decreasing the car body weight, there is a need to reduce fuel consumption of the vehicle as well as the environmental impact by lower production of emissions. Moreover, such reasons are mutually dependent or influence each other. The application of the aluminum sheets in hybrid car body production resulted in the need for innovative joining techniques, which could make it possible to successfully join sheets from aluminum alloys. Mechanical clinching is one of the new or innovative joining techniques, which belongs to cold-forming joining process, which makes it possible to join different kinds and thicknesses of sheets. Individual materials and thicknesses can be combined. The mechanically clinched joints are durable, and the joining process duration is very fast (duration of 1s) and does not have a distinctive impact on the environment; a protective layer of the sheets remains intact. The paper focuses on the evaluation of the properties of hybrid joints that were prepared by the single stroke clinching process with a rigid die. The hot-dip galvanized steel sheets DC06 and H220PD combined with the sheets from aluminum alloys EN AW 5754 (having different values of the hardness – H11, H22, and H24) and EN AW 6082 were used for joining. The results from experiments confirmed the mechanical clinching is the suitable technique for joining such combination of sheets. However, some considerations, such as the arrangement of the sheets about the punch and die, must be regarded.
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