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1

Experimental determination of dynamic and static elastic modulus of high-performance lightweight concrete

Abramowicz Małgorzata, Szewczyk Piotr, Fedorowicz Karol

Advances in Science and Technology. Research Journal

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2026

|

Vol. 20, no. 2

65--77

EN

This article focuses on the study of the elastic modulus of modern high-performance lightweight concrete. A characteristic feature of concrete, a brittle and composite material, is that its stress-strain characteristics are not exactly linear. This causes some problems in the definition of the Young's modulus. This paper compares a statically determined modulus, called the secant modulus, with a dynamically determined modulus. The obtained results show that the proportions between static and dynamic moduli are significantly different from the ratios known from the literature for normal concretes. For comparison, the results of similar tests for normal concrete with similar strength properties are presented.

2

Wpływ stosowania cementu wieloskładnikowego CEM II/C-M (V-LL) na podstawowe parametry wytrzymałościowe betonu

Walczak Aleksandra

Przegląd Budowlany

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2025

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R. 96, nr 5

90--93

PL

W niniejszym artykule zbadano wpływ stosowania cementu wieloskładnikowego CEM II/C-M (V-LL) w matrycy cementowej betonu na jego podstawowe parametry wytrzymałościowe. W myśl Europejskiego Zielonego Ładu i strategii opartej na zmniejszeniu ilości emisji dwutlenku węgla wprowadzono do mieszanki betonowej cement o zmniejszonej ilości klinkieru portlandzkiego w swoim składzie (CEM II) względem obecnie stosowanych w powszechnym budownictwie cementów (CEM I). Badaniu poddano podstawowe parametry wytrzymałościowe betonu: wytrzymałość na ściskanie, wytrzymałość na rozciąganie, moduł sprężystości. Sporządzono krzywą uziarnienia oraz krzywą przyrostu wytrzymałości na ściskanie betonu w czasie. Zbadane parametry uznano za strategiczne i mające znaczący wpływ na znajdujące praktyczne zastosowanie aspekty wymiarowania konstrukcji żelbetowych jak m.in. długość zakładu i zakotwienia prętów zbrojeniowych, ugięcie belek oraz nośność elementów.

EN

This article investigates the effect of using CEM II/C-M (V-LL) multi-component cement in the cement matrix of concrete on its basic strength parameters. In accordance with the European Green Deal and a strategy based on reducing carbon dioxide emissions, a cement with a reduced amount of Portland clinker in its composition (CEM II) was introduced into the concrete mix relative to the cements currently used in common construction (CEM I). The basic strength parameters of concrete were tested: compressive strength, tensile strength, modulus of elasticity. The grain size curve and the curve of increase in compressive strength of concrete over time were prepared. The studied parameters were considered strategic and have a significant impact on the practically applicable aspects of the dimensioning of reinforced concrete structures such as the length of the overlap and anchorage of reinforcing bars, the deflection of beams and the load carrying capacity of elements.

3

Dynamiczne właściwości fibrobetonu wytworzonego na bazie piasków odpadowych

Kobaka Janusz, Katzer Jacek, Zawidzki Machi

Pomiary Automatyka Robotyka

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2025

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R. 29, nr 1

75--79

PL

W artykule przedstawiono wyniki badań nieniszczących fibrobetonu z dodatkiem włókien stalowych wytworzonego na bazie piasków odpadowych. Belki fibrobetonowe o różnej zawartości włókien stalowych poddane były dwóm rodzajom drgań własnych: drganiom skrętnym i giętnym. Na podstawie przeprowadzonych testów i analizy Fouriera, wyznaczono częstotliwości tych drgań. Posłużyły one do określania dynamicznego modułu sprężystości, dynamicznego modułu odkształcenia postaciowego oraz dynamicznego współczynnika Poissona. Następnie określono wpływ włókien stalowych na te parametry. Badania wykazały, że dodatek włókien stalowych wpływa na zwiększenie dynamicznego modułu sprężystości oraz dynamicznego modułu odkształcenia postaciowego do pewnej krytycznej zawartości włókien, po przekroczeniu której, następuje zmniejszenie wartości tych modułów, ponadto włókna stalowe nie wpływają na wartości dynamicznego współczynnika Poissona.

EN

The article presents the results of non-destructive testing of steel fiber reinforced concrete (SFRC) based on waste sand. Fiber concrete beams with different steel fiber content were subjected to two types of free vibrations: torsional and flexural vibrations. Based on the tests and Fourier analysis, the frequencies of these vibrations were determined. They were used to determine the dynamic modulus of elasticity (Young’s modulus), the dynamic shear modulus (modulus of rigidity) and the dynamic Poisson’s ratio. In the next stage, the influence of steel fibers on these parameters was determined. The tests have shown that the addition of steel fibers increases the value of dynamic modulus of elasticity and the dynamic shear modulus up to a certain critical fiber content, beyond which the values of these moduli decrease; moreover, steel fibers do not affect the value of the dynamic Poisson’s ratio.

4

Studies on the behaviour of EPS polystyrene under compression in the light of standard provisions and subject literature

Słowiński Kamil

Materiały Budowlane

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2025

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nr 4

63--69

EN

The article discusses selected provisions of the PN-EN ISO 29469:2023-05 standard regarding the testing methodology and the method of assessing the results of the EPS polystyrene compression test, in the context of the preparation of test elements, the testing procedure and assessment of the results of the EPS polystyrene compression test and the possible possibility of structural use of this material. The provisions of the standard are discussed against the background of research results presented in the literature on the subject and the author's own research. The need to supplement the standard provisions is indicated.

PL

W artykule omówiono wybrane zapisy normy PN-EN ISO 29469:2023-05 dotyczące metody badań i sposobu oceny wyników próby ściskania polistyrenu EPS, w kontekście przygotowania elementów próbnych, procedury badań i oceny wyników próby ściskania polistyrenu EPS oraz ewentualnej możliwości konstrukcyjnego wykorzystania tego materiału. Zapisy normy omówiono na tle rezultatów badań przedstawionych w literaturze przedmiotu oraz badań własnych. Wskazano przy tym na konieczność uzupełnienia zapisów normowych.

5

Parametry techniczne w opisie przedmiotu zamówienia dla bezwykopowych renowacji: część 2

Nienartowicz Beata, Malesińska Agnieszka

Inżynieria Bezwykopowa

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2025

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nr 2

42--44

PL

Z tekstu dowiesz się: jakie znaczenie ma moduł sprężystości materiału, jakie materiały najczęściej wykorzystuje się do bezwykopowych renowacji, jaki kluczowy parametr zapewni bezpieczeństwo konstrukcji.

6

Influence of curing time on the effectiveness of polypropylene fibers in cement-stabilized soil improvement

Miturski Maciej

Inżynieria Bezpieczeństwa Obiektów Antropogenicznych

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2025

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Nr 3

57--66

EN

Soil stabilization is a commonly used method of improving subgrade properties in road construction. Despite many years of using this technology, intensive research continues to be conducted to enhance the effectiveness of stabilization processes. One approach used to improve the unconfined compressive strength (UCS) of stabilized soils is the incorporation of dispersed reinforcement. This study focuses on investigating the effect of polypropylene fibers on the effectiveness of cement-stabilized soil improvement as a function of time. For the study, samples were prepared based on two mixtures containing 4% cement. The first did not include any fibers, while the second contained 0.5% fibers. Six series of samples were prepared for each mixture, which were then subjected to uniaxial compression tests after 1, 3, 7, 14, 28, and 56 days of the curing process. Based on the collected data, an analysis was performed to examine the change in Effectiveness of Fiber Improvement (EFI) over time. The study of the test results showed that in the initial phase of curing, the effectiveness of fiber enhancement reached 165.9%, then gradually decreased over time to about 119.9%. Furthermore, the study also presented the significant impact of fibers on the E50 deformation modulus value, as well as the relationship between this parameter and the unconfined compressive strength of stabilized soil. Based on the results obtained, the mechanisms of soil improvement and their impact on the change in effectiveness over time were described. The presented results and conclusions facilitate a deeper understanding of the improvement of soil stabilized with polypropylene fibers.

7

Effects of Formaldehyde Scavenger on Mechanical, Physical, and Emission Test Results in Multi-Layer Pressed Chipboard Production

Çamlibel Osman, Peker Hüseyin, Ayata Ümit, Ulay Göksel

Drewno : prace naukowe, doniesienia, komunikaty

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2025

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Vol. 68, nr 215

Art. no. 201948

EN

This study investigates the effects of different formaldehyde scavenger (FS) ratios on the physical, mechanical, and chemical properties of fiberboard composites. Experimental analyses included measurements of thickness, density, modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB), shear strength (SS), moisture content, thickness swelling (TS), water absorption (WA), and formaldehyde emission (FE) levels. The results indicate that an increase in the FS ratio leads to a significant decline in mechanical properties. Specifically, MOR, MOE, and IB values decreased by 17.97%, 15.65%, and 16.33%, respectively. Changes in TS and WA were also observed, with TS increasing by up to 22.68% and WA decreasing by as much as 16.90%. In terms of formaldehyde emissions, a significant reduction was observed as the FS ratio increased. At a 15% FS ratio, formaldehyde emissions decreased by 43.24%, which is considered a positive outcome in terms of environmental and health impacts. Overall, the use of FS in specific ratios reduces FE while causing certain reductions in mechanical properties. These findings highlight the importance of optimizing FS usage for the production of low-FE fiberboards.

8

A new approach to determining the elastic modulus of structural materials

Zhigun Valery, Chatys Rafał, Plume Egils

Composites Theory and Practice

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2025

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R. 25, nr 3

217--225

EN

Stiffness characteristics are often decisive in the choice of material for structural parts. At the same time, the process of their determination for anisotropic materials does not fully satisfy the requirements in terms of reliability and reproducibility. This work is devoted to the development of an approach for determining the moduli of elasticity. An analysis of the Timoshenko approaches developed to estimate the shear component of deflection in transverse bending is presented. The drawbacks preventing their use as a basis for modern methods of determining the elastic components of structural materials are noted. An approach for determining the elastic moduli is proposed, the basis of which are the maximum values of deflections and angles of rotation of the cross-sections of a specimen under three-point transverse bending. The relationship between angular and linear displacements under the considered type of loading is established, which allows stable and reliable values of elasticity moduli to be obtained from the data of angular displacements. The acceptability of the proposed approach for determining the elastic moduli of both isotropic materials and composites is shown.

9

Evaluation of mechanical performance in polymer composites reinforced with particles and fibers

Ali Aenas Laith, Habeeb Diyar

Archives of Engineering Knowledge

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2025

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T. 11, Nr 1

13--19

EN

In this study, polymer-based hybrid composites were fabricated using the hand-casting technique, with unsaturated polyester resin serving as the core material. The composites were reinforced with a fixed volume fraction (15%) of glass fiber mat (GLASS-E). Two sets of samples were prepared: the first set was reinforced with graphite particles, while the second set used Kevlar mat fibers (50) as reinforcement instead of glass fibers. The effects of varying volume fractions (2%, 8%, 14%, 20%, and 26%) of graphite particles, with particle sizes ranging from 100 μm to 20 μm, on the mechanical properties of the composites were thoroughly investigated. Comprehensive mechanical tests including tensile, compression, impact, flexural, shear, and hardness tests - were conducted at room temperature to evaluate the material’s performance. The results revealed that increasing the volume fraction of graphite particles led to enhancements in tensile strength, compressive strength, tensile modulus, fracture toughness, and overall hardness. Additionally, flexural stiffness and shear stress values improved as the graphite content increased. Conversely, the compressive modulus showed an increase at lower graphite volume fractions but decreased at higher fractions in both groups. The impact resistance tests indicated that the hybrid composites reinforced with graphite particles and Kevlar fibers exhibited higher values of tensile strength, tensile modulus, compressive modulus, impact strength, and fracture toughness than those reinforced with glass fibers. However, the composites with glass fibers demonstrated superior compressive strength, stiffness, flexural strength, and shear stress compared to the Kevlar-reinforced composites.

10

Investigation on the dynamics of movement of cylindrical cleaning pigs through the bends of pipeline systems for fluid transportation

Stetsiuk Serhii, Doroshenko Yaroslav, Bondarenko Robert, Fіlipchuk Oleksandr, Volovetskyi Volodymyr

Zeszyty Naukowe. Transport / Politechnika Śląska

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2024

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z. 123

303--317

EN

Development and implementation of methods for cleaning the internal cavity of pipelines in the process of transporting fluids is important to ensure their energy efficiency and safe operation. The dynamics of the movement of one-piece cylindrical cleaning pistons made of various materials (silicone compound, self-destructive elastic polymer composition, polyurethane foam assembly foam) in the pipelines of pipeline systems intended for fluid transportation were studied by modelling and experimentally. The dynamics of movement of solid cylindrical cleaning pigs made from various materials (silicone compound, self-destructive elastic-polymer composition, polyurethane foam) in bends of pipeline systems intended for fluid transportation were studied through modelling and experiments. The analysis of forces acting on the pig during its movement in the pipeline bend was conducted, and the equations of pig motion based on Newton's second law were formulated. Contact forces of normal reaction, arising due to pig bending in the pipeline bend and determining the magnitude of frictional force between the pig and the inner wall of the bend, were determined based on classical bending theory. The impact of the material's modulus of elasticity, from which the pig is made, on the magnitude of contact forces of normal reaction at the pig pressing points against the inner wall of the pipeline bend was established. A method for determining the conditions under which pigs made from different materials will pass through pipeline bends without stopping and getting stuck was proposed. An equation for calculating the minimum allowable pig movement speed at the entrance to the bend to ensure its passage without stopping and getting stuck was derived.

11

The influence of chloride ions content on the mechanical properties of concrete

Szweda Zofia

Structure and Environment

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2024

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Vol. 16, no. 3

158--165

EN

This paper presents an analysis of the effect of concrete salinity on the splitting tensile strength of specimens taken directly from the HC-500 floor slab and the flexural and compressive strength and the value of the modulus of elasticity of specimens made under laboratory conditions from lightweight concrete and ordinary concrete. The tests were carried out in two variants: in the first, chloride ions were introduced into the concrete by the migration method and in the second, as an additive introduced directly with the batch water. The analysis showed that the additive can affect certain mechanical properties of concrete both favorably and unfavorably. The results indicate that it is important to examine the issue of the influence of salinity on concrete’s mechanical properties. This knowledge can be applied to the modeling of damage in reinforced concrete structures resulting from exposure to chloride-rich environments.

PL

W niniejszej pracy przedstawiono analizę badań wpływu zasolenia betonu na wytrzymałość na rozciąganie przy rozłupywaniu próbek pobranych bezpośrednio z płyty stropowej HC-500 oraz wpływu zasolenia na wytrzymałość na zginanie i ściskanie oraz na wartość modułu sprężystości próbek wykonanych w warunkach laboratoryjnych z betonu lekkiego i betonu zwykłego. Badania przeprowadzono w dwóch wariantach: w pierwszym po wprowadzeniu jonów chlorkowych do betonu metodą migracyjną w próbkach pobranych z płyt HC-500 i wykonanych z betonu lekkiego i w drugim, jako dodatek wprowadzony bezpośrednio z wodą zarobową w próbkach z betonu zwykłego. Przeprowadzone badania porównawcze różnych betonów z dodatkiem NaCl wykazały, że dodatek ten może wpływać zarówno korzystnie, jak i niekorzystnie na niektóre właściwości mechaniczne betonu. Przeprowadzone badania wskazują, że istotne jest dokładniejsze rozpoznanie zagadnienia wpływu zasolenia betonu na jego właściwości mechaniczne, co może być następnie wykorzystane w procesie modelowania zniszczeń konstrukcji żelbetowych wywołanych oddziaływaniem środowiska zawierającego chlorki.

12

Improving mechanical and thermal properties of unsaturated polyester resin by adding automotive glass waste

Hemadi Assis Ekhlass K., Al-Ahmady Kossay K., Sulyman Ebtahag Z.

Ochrona przed Korozją

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2024

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nr 10

294--305

EN

The primary goal of this study was to improve a number of mechanical properties of UPE (unsaturated polyester) by using available and cheap particulate fillers, such as reinforcement with powder with a particle size of 75 μm. A composite of UPE with automotive glass waste (as filler materials) was prepared, and some mechanical and thermal properties were studied at certain weight percentages (5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%). A comparison was made between the polymeric composites before and after the process of reinforcing them with waste automotive glass, and it was found that with a 30% content of these additives they showed good mechanical properties. These additions were made at different temperatures: 8°C, 25°C and 50°C. The results before and after the reinforcement process for polymer composites showed that there was an improvement in the mechanical properties (compressive strength, hardness and impact resistance) with a decrease in the modulus of elasticity (Young’s modulus). When processing was carried out at a temperature of 8°C, a decrease in the values of the mechanical properties (compressive strength, impact strength, modulus of elasticity, thermal conductivity) was observed in varying proportions, with an increase in the values of hardness. Conversely, when the samples were heated to a temperature of 50°C, there was an increase in the values of the above-mentioned properties and a significant decrease in the hardness values. Throughout the research, various measurement techniques were used, including scanning electron microscopy (SEM), infrared spectroscopy (IR) and thermogravimetric analysis (TGA). Their purpose was to monitor the changes that occurred in the polymer as a result of the use of the reinforcing material (automotive glass).

PL

Głównym celem badań było poprawienie właściwości mechanicznych UPE (nienasyconego poliestru) poprzez zastosowanie dostępnych i tanich wypełniaczy cząsteczkowych, na przykład przez wzmocnienie proszkiem o wielkości cząstek wynoszącej 75 μm. Przygotowano kompozyt UPE ze szklanymi odpadami przemysłu motoryzacyjnego (jako materiałem wypełniającym) i zbadano wybrane właściwości mechaniczne i termiczne przy określonych procentach wagowych (5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% i 50%). Porównano kompozyty polimerowe przed procesem wzmacniania odpadami szklanymi i po nim. Stwierdzono, że przy 30-procentowym udziale tych dodatków wykazywały one dobre właściwości mechaniczne. Dodatki zostały wprowadzone w różnych temperaturach: 8°C, 25°C i 50°C. Analiza wyników przed wzmocnieniem kompozytów polimerowych i po tym procesie wykazała, że nastąpiła poprawa właściwości mechanicznych (wytrzymałości na ściskanie, twardości i udarności) przy spadku modułu sprężystości (modułu Younga). Po przetwarzaniu w temperaturze 8°C odnotowano spadek wartości parametrów mechanicznych (wytrzymałości na ściskanie, udarności, modułu sprężystości, przewodności cieplnej) w różnych proporcjach przy jednoczesnym wzroście twardości. Z kolei po podgrzaniu próbek do temperatury 50°C zwiększyły się wartości wymienionych właściwości i znacznie zmniejszyła twardość. W badaniach wykorzystano różne techniki pomiarowe, w tym skaningową mikroskopię elektronową (SEM), spektroskopię w podczerwieni (IR) i analizę termograwimetryczną (TGA), w celu zweryfikowania zmian zachodzących w polimerze w wyniku zastosowania materiału wzmacniającego (szklanych odpadów przemysłu motoryzacyjnego).

13

Study of the Behaviour of Moment-Resisting Connection of Softwood Timber Elements

Fabriciuss Janis, Ozola Lilita

Inżynieria Mineralna

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2024

|

Vol. 1, no. 2

art. no. 25

EN

Timber moment-resisting connections present opportunities for streamlined architectural design using timber portal frames with rigid knee junctions, enabling open floor plans by eliminating the need for additional bracing or interior columns. This flexibility empowers architects to craft more versatile floor layouts, enhancing spatial aesthetics and functionality. However, moment-resisting connections between timber members, especially crossing ones, present several challenges – complex design, demanding meticulous detailing and precise fabrication and also lack of a detail design format in codes. One of the biggest disadvantages of timber moment-resisting connections made by steel dowels is development of relative rotation due to the timber as well as dowel’s elastic-plastic behaviour, i.e., such connection may be referred to a semi-rigid group. The main objective of this study is to conduct a detailed investigation of semi-rigid timber connections by performing experimental tests of L-shape models, including examination of timber strength and stiffness properties. The rotational displacement between joined members was determined using measured distances between surface points by Particle Image Velocimetry (PIV). The experimental results are compared with an equivalent linear calculation model. Different connection models are treated by Dlubal RFEM software tools using experimentally obtained embedment stiffness variables. It is found that the linear behavior of the semi-rigid connection is up to approximately 40% of the connection's design capacity, after which distinctly nonlinear force-deformation relationship develops.

14

Effect of Calcium Lignosulfonate Additive on Some Physical and Mechanical Properties of High-Density Fiberboard

Çamlibel Osman, Ayata Ümit, Peker Hüseyin

Drewno : prace naukowe, doniesienia, komunikaty

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2024

|

Vol. 67, nr 214

Art. no. 195844

EN

Calcium lignosulfonate (CLS) (C20H24CaO10S2) is widely used in various industries today, including wood, construction, food, agriculture, and textiles. There are currently few studies on the addition of CLS chemicals to various fiberboards. This study was designed to explore the outcomes of the interaction between CLS and the boards, with the aim of expanding the potential applications of this chemical. We incorporated CLS at varying percentages (6%, 8%, and 10%) as an adhesive additive in high-density fiberboard (HDF) produced using urea-formaldehyde (UF) resin in a laboratory setting. We assessed its impact on several physical properties - thickness swelling (TS), den-sity, and water absorption (WA) - and mechanical properties: modulus of rupture (MOR), internal bond strength (IB), modulus of elasticity (MOE), and surface soundness (SS). A control group was created using prepared boards, enabling the comparison of results between boards made with and without CLS additives. According to the results of a multivariate analysis of variance, the CLS per-centage showed no significant effect on density, MOE, and SS. However, it significantly influenced TS, WA, IB, and MOR, resulting in reductions of 4-12% for SS, 6-12% for MOR, and 2-22% for IB, while increasing TS by 20-130%, WA by 25-84%, and MOE by 1-3%. It was observed that the use of CLS led to differing results in the tests conducted on the produced HDF materials.

15

Dimensional stability and mechanical performance of face-glued spruce-pine-fir and Douglas-fir studs

Cook Sophia, Ghavidel Amir, Zhou Jianhui

Drewno : prace naukowe, doniesienia, komunikaty

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2024

|

Vol. 67, nr 214

Art. no. 193420

EN

Warpage of dimensional lumber has been identified as the major issue for its use in wood construc tion prefabrication in North America. Face-gluing is a promising technique to mitigate warping of dimensional lumber. This paper studies the dimensional stability and mechanical performance of 2-ply face-glued lumber as a means of reducing warpage in both spruce-pine-fir (S-P-F) and Douglas-fir (D. fir) lumber. Planks were paired and subsequently laminated based on their initial dynamic modulus of elasticity (MOE) and shape compatibility. Warp was measured in twist, bow, and crook at varying moisture contents. Mechanical performance was measured in terms of the MOE, modulus of rupture (MOR), and shear strength. This pairing regime between component planks offers a means to reduce the twist and bow tendencies of face-glued lumber while increasing the unifor mity of lumber strength. Flexural MOE and MOR performances were consistent with visual grades No.1/No.2, showing the potential of face-glued lumber as a value-added product for the automatic prefabrication of wood constructions.

16

Synergistic use of nano‑silica to enhance the characterization of ambient‑cured geopolymer concrete

Swathi B., Vidjeapriya R.

Archives of Civil and Mechanical Engineering

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2024

|

Vol. 24, no. 1

art. no. e4, 2024

EN

As global urbanization flourishes, the adverse effects on the environment also incredibly increase. This urbanization leads to the evolution of construction and building materials. To meet the requirements of eco-balanced construction materials without compromising their original properties, many evolutions of concrete are in practice nowadays. One such evolution of concrete is geopolymer concrete. The objective of the current study is to produce high-strength geopolymer concrete using ground granulated blast furnace slag (GGBS), metakaolin (MK), and nano-silica (NS) in ambient-cured conditions. The influence of nano-silica in the geopolymer concrete is evaluated by workability, setting time, mechanical strength, durability properties, and microstructural analyses, which include scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and correlation analysis. In this research, the effect of nano-silica on formulating the equation for modulus of elasticity was determined. Nano-silica was replaced at a percentage of 1, 2, and 3% of the binder material. It is summarized that the molar ratios and properties of the precursor materials are the defining factors in altering the systems of geopolymer concrete. The highest strength of 89.4 MPa at 28 days of ambient-cured concrete with outstanding durability performance was achieved.

17

Quasi-Static Investigations of 240-Bloom Gelatine for Ballistic Tests

Fikus Bartosz, Basiński Norbert

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2023

|

Vol. 14, Nr 1 (51)

61--72

EN

The paper presents the results of investigations of ballistic gel properties in quasi-static conditions. Specimens were prepared using the 240 Bloom gelatine, which was determined by product availability. Tests were carried out making use of a material testing machine to estimate the influence of gel share on stress-strain characteristics. Considered values of a gel mass content were equal to 10, 12, and 14%. Assumed parameters were determined on the material calibration stage conducted with steel balls with a diameter of 4.5 mm. The most significant influence of a gel content on mechanical properties of specimens were observed for a share of 10% and 12%. The conducted preliminary tests are a part of investigations aimed at assessment if it is possible to calibrate the ballistic gel making use of mechanical characteristics obtained in quasi-static tests without shooting.

PL

Niniejsza praca stanowi opis oraz wyniki prac realizowanych w ramach badań quasi-statycznych żelatyny (o sile żelowania 240 Bloom) przeznaczonej do testów balistycznych, która jest najczęściej stosowanym substytutem tkanek miękkich w badaniach balistyki końcowej. W ramach prac przeprowadzono proces przygotowania materiału do badań, jego kondycjonowania, kalibracji oraz badań w warunkach quasi-statycznych w celu określenia modułu sprężystości wzdłużnej oraz modułu sprężystości objętościowej. Na podstawie wstępnych badań kalibracyjnych podjęto decyzję o przebadaniu próbek o zawartości żelatyny równej 10 %, 12 % oraz 14 %. Rezultaty badań (krzywe siła-przemieszczenie) pozwoliły na ocenę odkształceń oraz naprężeń (inżynierskich oraz rzeczywistych) występujących w badanym materiale. To z kolei pozwoliło na ocenę wartości wyżej wspomnianych modułów sprężystości. Należy zwrócić uwagę na relatywnie duży rozrzut uzyskanych wyników, co może sugerować konieczność dalszych prac nad precyzją wykonania próbek. Uzyskane wyniki wykazały łatwość oraz efektywność zastosowanej metodyki przygotowania próbek, jak również znaczący wpływ zawartości żelatyny na moduł sprężystości wzdłużnej (szczególnie w przypadku dwóch niższych wartości zawartości żelatyny). Zdecydowania mniejszą rozbieżność zauważono w przypadku modułu sprężystości objętościowej. Ponadto, okazało się, że przygotowanie próbek o udziale masowym 20 % jest nieuzasadnione ze względu na dużą czasochłonność całości procesu.

18

Wpływ wybranych parametrów na wartość modułu sprężystości taśm przenośnikowych z rdzeniem poliestrowo-poliamidowym

Zarzycki Jacek

Mining – Informatics, Automation and Electrical Engineering

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2023

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R. 61, nr 4

56--62

PL

W artykule zestawiono informacje na temat wpływu wybranych czynników na wartość modułu sprężystości taśm przenośnikowych z rdzeniem tekstylnym. Przedstawiono metodę badania modułu sprężystości w warunkach laboratoryjnych, wskazano, jak wartość modułu sprężystości zmienia się w zależności od zakresu obciążenia oraz temperatury. Moduł sprężystości jest to parametr, którego wartość jest niezbędna do poprawnego projektowania w szczególności długich i niekonwencjonalnych przenośników taśmowych.

EN

The article compiles information on the influence of selected factors on the elasticity modulus of conveyor belts with a textile core. It presents a laboratory method for testing the modulus of elasticity, highlighting how its value changes depending on the load range and temperature. The modulus of elasticity is a parameter essential for the proper design of conveyor belts, especially those that are long or unconventional.

19

The influence of selected parameters on the elasticity modulus of conveyor belts with a polyester-polyamide core

Zarzycki Jacek

Mining – Informatics, Automation and Electrical Engineering

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2023

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R. 61, nr 4

49--55

EN

The article compiles information on the influence of selected factors on the elasticity modulus of conveyor belts with a textile core. It presents a laboratory method for testing the modulus of elasticity, highlighting how its value changes depending on the load range and temperature. The modulus of elasticity is a parameter essential for the proper design of conveyor belts, especially those that are long or unconventional.

PL

W artykule zestawiono informacje na temat wpływu wybranych czynników na wartość modułu sprężystości taśm przenośnikowych z rdzeniem tekstylnym. Przedstawiono metodę badania modułu sprężystości w warunkach laboratoryjnych, wskazano, jak wartość modułu sprężystości zmienia się w zależności od zakresu obciążenia oraz temperatury. Moduł sprężystości jest to parametr, którego wartość jest niezbędna do poprawnego projektowania w szczególności długich i niekonwencjonalnych przenośników taśmowych.

20

Analysis of using the empirical model of organic soil consolidation to predict settlement

Meyer Zygmunt, Olszewska Magdalena A.

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 2

111--117

EN

The paper describes two models for determining the constrained elasticity modulus of organic soils based on the settlement of an overloading embankment. In these methods, based on the settlement of the embankment of the load exerted on the subsoil, using the inverse problem, it is possible to determine the constrained modulus. A parameter determined in this way can also be determined during consolidation. Changes in the settlement at successive stages of consolidation can be used to determine the constrained modulus of the organic soil at a given point in time. Assuming a “temporarily stable” (quasi-stationary) state at each analysed stage of consolidation. The constrained elasticity modulus was determined for the settling at a given moment. constrained modulus tests of organic soils were carried out for two embankments previously described in the literature. In this case, the modulus was also analysed during consolidation. These embankments are founded on peat and peat-gyttja substrates. In both cases, the layer of organic soil was 4 m. The presented methods with the assumption of a one-dimensional state of deformation, despite the state of spatial stress, can be used during construction using the “design and build” technology. The constrained modulus determined from the embankment overload will represent the actual deformations – volumetric deformations (including other deformations that actually occurred) during the consolidation period. The paper was concluded with several conclusions.