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1

A comprehensive case study to the implicit and explicit approach in finite element analysis

Huner Umit, Irsel Gurkan, Bekar Umut, Szala Mirosław

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 2

407--417

EN

The primary aim of this study is to conduct a comprehensive comparative evaluation of implicit and explicit finite element solution methodologies employed in structural analysis. This research examines the characteristics and performance differences between these two approaches, using two diverse case studies as illustrative examples. The FEM solution was performed nonlinearly by defining the linear elastic and plasticity properties of the material. The first case study focuses on a three-point bending test of a beam subjected to a slow deformation rate, while the second case study examines the damage mechanics of a pressure vessel experiencing a high deformation rate. It was found that the implicit solution method operates under the premise that displacement is independent of time, allowing for a more stable analysis in certain scenarios. On the other hand, the explicit method inherently incorporates time as a variable, making displacement a function of time. Once a solid understanding of the system's response is established, transitioning to explicit methods for more dynamic scenarios can lead to a more comprehensive and effective resolution of complex engineering problems. By carefully selecting the appropriate analysis method based on the specific characteristics of the loading conditions and the nature of the forces involved, engineers can optimize their simulations and enhance the reliability of their results.

2

Agroecological Assessment of Soybean Varieties under the Conditions of the Right Bank Forest Steppe of Ukraine

Petrychenko Vasyl, Kobak Svitlana, Kolisnyk Serhii, Chorna Victoria, Korniychuk Oleksandr, Pantsyrev Oleksandr

Journal of Ecological Engineering

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2024

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Vol. 25, nr 9

60-69

EN

Agroecological testing of soybean varieties of domestic and foreign selection was carried out during 2020-2022 on the experimental field Institute of Feed Research and Agriculture of Podillya of NAAS, which is located in the zone of the right-bank forest-steppe of Ukraine. The subject of research was domestic soybean varieties (Diadema Podillia, Tytan, Kobuko, Monada, Triada (Institute of Feed Research and Agriculture of Podillya of NAAS); Vorskla, Lehenda (National Research Center “Institute of Agriculture of the National Academy of Sciences”) and foreign (Merlin, Kardiff, Kent, Padua (SAATBAU LINZ eGen); Kioto, Kordoba, Briunensis (Semences Prograin Ink.); Senator, Alihator (Euralis Semences); Sultana (RAGT Semences) selection. All soybean varieties studied during 2020‒2022 were entered into the State Register of plant varieties suitable for distribution in Ukraine. The maximum seed yield in the zone of the right-bank forest-steppe of Ukraine was recorded in the following varieties: Triada (3.41 t/ha), Kioto (3.29 t/ha), Alihator (3.25 t/ha), Kobuko (3.19 t/ha), Monada (3.15 t/ha), Kardiff (3.06 t/ha) and Tytan (3.05 t/ha). According to the results of the analysis of the mass of 1000 seeds, its highest indicators were noted in soybean varieties: Tytan–194 g, Alihator–192 g, Kent–193 g, Sultana–200 g. According to the results of the biochemical analysis of soybean seeds, it was found that most of the studied varieties provided the content crude protein is more than 40%, while the Merlin, Alihator, Triada, Cardiff and Kent varieties had a crude protein content of 37.1-39.1%. The obtained results of the content of amino acids in soybean seeds show more noticeable indicators in the Tytan soybean variety. Thus, on the basis of a comprehensive approach to soybean productivity indicators, such varieties of domestic selection as Tytan and Kobuko, as well as foreign selection of Kioto, are recommended for agricultural production in the areas of seed production, animal feed and raw material in the selection process.

3

Plastic deformation mechanisms in BCC single crystals and equiatomic alloys: Insights from nanoindentation

Dominguez-Gutierrez Francisco Javier, Papanikolaou Stefanos, Bonfanti Silvia, Alava Mikko

Computer Methods in Materials Science

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2024

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Vol. 24, No. 1

37--49

EN

Deformation plasticity mechanisms in alloys and compounds may reveal the material’s capacity towards optimal mechanical properties. We conducted a series of molecular dynamics (MD) simulations to investigate plasticity mechanisms due to nanoindentation in pure tungsten, molybdenum, and vanadium body-centered cubic single crystals, as well as the body-centered cubic, equiatomic, random solid solutions (RSS) of tungsten–molybdenum and tungsten–vanadium alloys. Our analysis focuses on a thorough, side-by-side comparison of dynamic deformation processes, defect nucleation, and evolution, along with corresponding stress–strain curves. We also checked the surface morphology of indented samples through atomic shear strain mapping. As expected, the presence of Mo and V atoms in W matrices introduces lattice strain and distortion, increasing material resistance to deformation and slowing down dislocation mobility of dislocation loops with a Burgers vector of 1/2 〈111〉. Our side-by-side comparison displays a remarkable suppression of the plastic zone size in equiatomic W–V RSS, but not in equiatomic W–Mo RSS alloys, displaying a clear prediction for optimal hardening response of equiatomic W–V RSS alloys. If the small-depth nanoindentation plastic response is indicative of overall mechanical performance, it is possible to conceive a novel MD-based pathway towards material design for mechanical applications in complex, multi-component alloys.

4

Microalloying of Continuous Cast Aluminum Strip and Structural Modification Using Plastic Treatment to a 9 μm Foil (Patent no. 39762, P-377/76)

Purenović M. M., Purenović Jelena M., Baralić J. Č.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

345--357

EN

Innovative procedure of microalloying continuous cast aluminum strip, thickness 10 mm, by Be, Zr and Mn using 3C Pechiney technology (no. 39762, P-377/76), and modifying the existing parameters for strip casting and crystallization was implemented under industrial conditions with two randomly selected batches 2×8 tones, without previous selection of standardized quality of aluminum, purity Al 99.5%, obtained by electrolysis. The application of microalloying and overall structural modification of the technology resulted in obtaining nanoscale, ultra-thin, compact oxide high-gloss film with uniform surface of continuous cast strip, instead of the usual thick and porous oxide film. The outcome of microalloying the obtained equiaxed fine-grained nano/micro structure was avoiding anisotropic and dendritic microstructure of the strip, and improving deformation and plastic properties of modified continuous cast strip subjected to the technology of plastic treatment by rolling until the desired foil thickness of 9 μm was obtained. The invention of microalloying and structural modification, including multiplying effect of several components, directly or indirectly, changed numerous structurally-sensitive properties. The obtained nano/micro structure of crystal grains with equiaxed structure resulted in the synergy of undesirable <111> and inevitable <100> and <110> textures. Numerous properties were significantly enhanced: elastic modulus was improved, and intensive presence of cracks in warm forming condition was prevented due to rapid increase of the number of grains to 10000 grains/cm2 in as-cast state.

5

Analysis of application of gradient concrete models to assess concrete cover degradation under reinforcement corrosion

Yurkova Kseniya, Krykowski Tomasz

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 4

109--123

EN

The paper presents a comparative analysis of the application of two nonlocal gradient-formulated models to evaluate the concrete cover degradation time. Calculations were made taking into account the increase in the volume of the steel ring around the perimeter of the reinforcement bar. The results of the calculations were compared with the results of experimental studies published in the literature and with the elastic-plastic model based on the Menetrey-Willam surface, in which the objectivity of the obtained results depends on the fracture energy. In addition, the paper compares solutions using different contact models and cohesion models.

6

Influence of material thickness on the ductile fracture of steel plates for shipbuilding

Jakub Kowalski, Janusz Kozak

Polish Maritime Research

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2022

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nr 3

160--166

EN

In the shipbuilding industry, the risk of brittle fractures is relatively high because some units operate in arctic or subarctic zones and use high thickness (up to 100 mm) steel plates in their structures. This risk is limited by employing certified materials with a specific impact strength, determined using the Charpy method (for a given design temperature) and by exercising control over the welding processes (technology qualification, production supervision, and non-destructive tests). However, for offshore constructions, such requirements may prove insufficient. For this reason, regulations employed in constructing offshore structures require conducting crack tip opening displacement (CTOD) tests for steel and welded joints with thicknesses exceeding 40 mm for high tensile strength steel and 50 mm for other steel types. Since classification codes do not accept the results of CTOD tests conducted on specimens of sub-sized dimensions, the problem of theoretically modelling the steel construction destruction process is of key importance, as laboratory tests for notched elements of considerable thickness (100 mm and higher) are costly and problems stemming from high loads and a wide range of recorded parameters are not uncommon. The aim of this research is to find a relationship between material thickness and CTOD value, by establishing and verifying a numerical model that allows recalculating a result obtained on a sub-size specimen to a full- size specimen for a ductile fracture mode. This work presents results and conclusions from numerical modelling and compares them with laboratory test results of the elastic-plastic properties of high thickness steel, typically used in offshore applications.

7

Research on parameters of MMC fracture criterion for advanced high strength dual-phase steel sheets

Fu Qiutao, Li Di, Song Hui, Liu Xingfeng, Lu Zipeng, Cui Hongjian

Journal of Theoretical and Applied Mechanics

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2022

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Vol. 60 nr 2

253--265

EN

To predict the shear fracture, tests of advanced high-strength DP steels have been carried out, and fracture models of DP steels have been established using the MMC fracture model. The MMC fracture parameters were obtained through multiple sets of experiments and stress triaxiality solved by simulation. The result was verified by stretch-bending, Nakazima tests and simulations. It shows that the MMC criterion is suitable for predicting ductile fracture of DP980, 1180. The correlation between the parameters of the MMC criterion and DP steel material properties can reduce the amount of tests data required.

8

Effect of simulated axial residual stress and transverse residual stress in welded P92 pipe and plates including plasticity error

Pal Vinay Kumar, Singh Lokendra Pal

Journal of Mechanical and Energy Engineering

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2022

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Vol. 6, No 2

1--18

EN

The paper deals with the measurement of residual stresses in P92 welded pipe using the blind hole drilling technique. The post weld heat treatment (PWHT) of a P92 welded pipe was also conducted to study their effect on residual stresses. The P92 pipe weld joints were prepared using gas tungsten arc welding process. The residual stress measurement was carried out using a strain gauge rosette that was associated with the plastic deformation of the material and a stress concentration effect of a multi-point cutting tool. A corrective formulation was developed for calculating the corrected value of residual stresses from the experimentally obtained strain value. The Strain gauge response was estimated experimentally using tensile testing for uniaxial loading while a finite element analysis was performed for biaxial loading. A gas tungsten arc welds joint was prepared for a conventional V-groove and a narrow groove design.

9

Coupled Thermomechanical Eulerian-Lagrangian Analysis of the KOBO Extrusion Process

Wójcik Marta, Skrzat Andrzej

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1185--1193

EN

Numerical simulations of the KOBO extrusion process are presented in this paper. The coupled thermomechanical Eulerian-Lagrangian approach was applied for the three-dimensional finite element model. The dynamic explicit Euler forward method was used in numerical calculations. The elastic-plastic Chaboche model assuming isotropic and kinematic hardening under variable temperature conditions was applied to describe the behaviour of the material under cyclic loading. In numerical computations Chaboche material model implemented in commercial software, as well as the proprietary one written as FORTRAN procedure were tested. The numerical results present the stress and strain distributions in the extruded material, as well as an increase of temperature due to the plastic work and friction. The shape of plastic strain zones was verified experimentally. The approach presented in the paper is a promising numerical tool to simulate the KOBO process.

10

Application of a geometrically nonlinear elastoplastic gradient-enhanced damage model with incremental potential to composite microstructures

Boussetta H., Dittmann J., Wulfinghoff S.

Archives of Mechanics

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2021

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Vol. 73, nr 5-6

499--540

EN

The prediction of inelastic processes like plastic deformations and cracks within the microstructure of modern man-made materials by realistic, yet simple and efficient continuum models remains a major task in material modelling. For this purpose, gradient-extended standard dissipative solids represent one of the most promising model classes, which is also formulated and applied in this work to investigate microscopic failure mechanisms in three exemplary three-dimensional composite microstructures. The model combines geometrically nonlinear isotropic elastoplasticity with an isotropic damage model with gradient-extension. For the numerical treatment, a variational constitutive update algorithm based on the exponential map is applied. The model is used to provide insight into the microscopic failure of a brittle woven composite material, a particle-reinforced plastic and a carbon fiber reinforced composite. The influence of different microstructural and material parameters on the overall failure behavior is characterized. Adaptive meshing is used to enable a refined numerical resolution of the cracked regions.

11

Static and kinematic shakedown theorems in diffusion-induced plasticity

Peigney Michael

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 2

415--424

EN

We present shakedown theorems applying to cyclically loaded media in which plastic flow and diffusion of guest atoms are coupled. The presented theorems are in the spirit of Melan and Koiter theorems in plasticity. They allow one to estimate the loading parameters for which elastic shakedown occurs, i.e. for which the plastic strain stabilizes to a time-independent limit. An application related to lithium-ion batteries is presented.

12

Dieless drawing process for elongation of thin copper and copper alloy wire

Milenin Andrij, Kustra Piotr, Wróbel Mirosław, Pidvysots’kyy Valeriy, Paćko Marek

Journal of Metallic Materials

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2019

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Vol. 71, no. 3

12--15

EN

The article proposes a new process for the production of thin wires made of copper and copper alloys. The proposed process is based on the idea of dieless drawing. The workpiece for dieless drawing is a thin wire obtained through a conventional drawing method. The proposed technology is based on a multi-pass process. The deformation parameters in each pass are determined on the basis of an analysis of the dependence of the flow stress of the material on the strain, strain rate and temperature. For this purpose, plastometric tests of a copper and CuZn37 alloy were performed. In order to determine technological plasticity and roughness propagation during dieless drawing, physical and numerical modelling of this process were performed. The obtained data were used in the practical implementation of the dieless drawing technology.

PL

Artykuł poświęcono nowemu procesowi produkcji cienkich drutów z miedzi i jej stopów. Zaproponowany proces jest oparty o idee ciągnienia bezmatrycowego. Wsadem do ciągnienia bezmatrycowego jest cienki drut, wyprodukowany za pomocą metody konwencjonalnego ciągnienia. Proponowana technologia jest oparta na wieloprzepustowym procesie. Parametry odkształcenia w każdym przepuście są wyznaczane na podstawie analizy zależności naprężenia uplastyczniającego od odkształcenia, prędkości odkształcenia i temperatury. W tym celu przeprowadzono badania plastometryczne miedzi i stopu CuZn37. Celem wyznaczenia technologicznej plastyczności oraz propagacji chropowatości powierzchni drutu w trakcie ciągnienia bezmatrycowego wykonano fizyczne i numeryczne modelowanie procesu. Otrzymane dane wykorzystano podczas praktycznej implementacji procesu ciągnienia bezmatrycowego.

13

Research of the dual phase steel DP450 properties from the forming aspects

Bilik Jozef, Tittel Viktor, Sobota Robert, Suba Roland

Hutnik, Wiadomości Hutnicze

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2019

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Vol. 86, nr 1

14--17

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.

14

Some geotechnical properties of pure and waste gypsum for geoelectrical grounding applications

Mohd Tadza Mohd Yuhyi, Mazelan Nurmazuria, Yusri Nur Farahana, Abdullah Amizatulhani

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 3

97--106

EN

Natural occurring gypsum is a soft mineral consists of hydrated calcium sulphate, mainly used in cement industry. On the other hand, red gypsum (RG) is a waste generated from a sulphate process of ilmenite ore to acquire titanium dioxide. Due to the gypsum content in both materials are similar, it is expected that both gypsum type can be used for similar engineering applications. In this study, RG was tested and compared to pure gypsum for geoelectrical grounding applications. The geotechnical properties and plasticity characteristics were carefully measured and tested. In addition, X-ray fluorescence (XRF) was employed to study the chemical constituents of the materials. Test results showed that, the geotechnical properties of RG is different to that of white gypsum. The plasticity index (PI) of RG was 239.6% greater due to the presence of Fe ions. Surprisingly, the electrical resistivity of both material were found to be similar. It was also noted that, although the plasticity of pure gypsum is high, the plasticity of pure gypsum was found to be short lived primarily due to instantaneous exothermic reaction between water and semihydrated gypsum. The change in the plasticity also affected the resistivity as gypsum hardened after short duration. Based on the geotechnical and plasticity characteristics determined, RG was found to be a better as grounding material as compared to gypsum.

15

Plasticity and swell-shrink behaviour of electrokinetically stabilized virgin expansive soil using calcium hydroxide and calcium chloride solutions as cationic fluids

James Jijo, James Archana, Kumar Arun, Gomathi Elumalai, Prasath Karunakaran Kamal

Civil and Environmental Engineering Reports

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2019

|

Vol. 29, no. 1

128--146

EN

This investigation focussed on the plasticity and swell-shrink behaviour of an expansive soil that was stabilized using electro kinetic stabilization (EKS) techniques with cationic fluids for enhancement of stabilization. 0.25 M solutions of calcium hydroxide and calcium chloride were used as cationic fluids. An electro kinetic (EK) cell of dimensions 500 mm x 150 mm x 160 mm with inert graphite electrodes of size 140 mm x 160 mm x 5 mm was adopted for the stabilization process, carried out at an applied voltage of 40 V over a period of 6 hours. After the duration of the test, stabilized soil sample was subjected to Atterberg limits and free swell tests to determine its plasticity and swell-shrink characteristics. The results of the investigation found that both fluids were capable of reducing the plasticity and swell-shrink behaviour of the soil with different levels of effectiveness.

PL

W badaniach skupiono się na plastyczności i kurczeniu się gleby, która została ustabilizowana za pomocą technik stabilizacji elektrokinetycznej (EKS) z płynami kationowymi. Jako płyny kationowe stosowano 0,25 M roztwory wodorotlenku wapnia i chlorku wapnia. Do procesu stabilizacji przyjęto ogniwo elektrokinetyczne (EK) o wymiarach 500 mm x 150 mm x 160 mm z obojętnymi elektrodami grafitowymi o wymiarach 140 mm x 160 mm x 5 mm, przy zastosowaniu napięcia 40 V przez okres 6 godzin. Po zakończeniu testu stabilizowaną próbkę gleby poddano testom Atterberga i badaniom swobodnego spęcznienia w celu określenia jego plastyczności i charakterystyki kurczenia się. Wyniki badania wykazały, że oba płyny były w stanie zmniejszyć plastyczność i kurczenie się gleby przy różnych poziomach skuteczności.

16

Fuzzy Logic Enhancement of Material Strain Hardening Data Obtained in the Heyer's Test

Skrzat A., Wójcik M., Bąk Ł.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

1059--1065

EN

Fuzzy logic determination of the material hardening parameters based on the Heyer’s method was applied in this research. As the fuzzy input variables, the length of two measuring bases and the maximum force registered in the Heyer's test were used. Firstly, the numerical experiment (the simulation of the fuzzification of the input data) with the assumed disturbance of input variables was performed. Next, on the basis of experimental investigations (eleven samples made from the same material), the membership functions associated with the input data were created. After that, the fuzzy analysis was examined. Fuzzy material hardening constants obtained by means of the α-level optimization and the extension principle methods were compared. Discrete values of the hardening data are found in the defuzzification process, by application of the mass center method.

17

Role of dilatancy angle in plasticity-based models of concrete

Wosatko Adam, Winnicki Andrzej, Polak Maria Anna, Pamin Jerzy

Archives of Civil and Mechanical Engineering

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2019

|

Vol. 19, no. 4

1268--1283

EN

The so-called concrete damaged plasticity (CDP) model is frequently employed by ABAQUS users to simulate the behaviour of concrete. One important aspect of the model, namely the representation of material dilatancy, is evaluated in the paper. The role of the dilatancy angle in pressure-dependent plasticity models is reviewed. The plastic potential adopted in the CDP model is discussed. It is shown that the definitions of the angle in the CDP model and in the Burzynski–Drucker–Prager (BDP) plasticity model for a continuum can lead to different angle magnitudes. Two tests on concrete configurations are simulated to illustrate how strongly the angle influences the results: the Kupfer benchmark of a panel under uniaxial or biaxial compression and the punching shear response in a slab-column connection. The importance of viscosity in cracking simulation is thereby mentioned, the results are compared with experimental ones and mesh sensitivity is verified. Recommendations for analysis of concrete mechanics problems are formulated.

18

Odkształcalność plastyczna i anizotropia struktury taśm z nowych stali typu maraging

Pawlak S. J.

Stal, Metale & Nowe Technologie

|

2018

|

nr 11-12

64--68

PL

W pracy analizowano kierunkowość własności i struktury taśm cienkich wytworzonych ze stali X2NiMoTi19-4-1 i X1CrNiMoTi11-10-1, tj. odpowiednio bezkobaltowej stali typu maraging i stali odpornej na korozję umacnianej wydzieleniowo (SONK-UW). Do oceny anizotropii struktury stali i rozkładu wielkości ziarna wykorzystano mikroskop skaningowy z detektorem EBSD. Badane stale – pomimo całkowicie różnych składów chemicznych – mają bardzo zbliżone własności mechaniczne w stanie przesyconym oraz po starzeniu.

EN

The paper analyses the directionality of the tensile properties and microstructure of cold-rolled thin strips made of the X1NiMoTi19-4-1 Co-free maraging steel and the X1CrNiMoTi11-10-1 precipitation hardening stainless steel. The scanning electron microscopy EBSD technique was used to assess microstructural anisotropy and the grain size distribution. It was demonstrated that both steels – despite entirely different chemical compositions – exhibit very similar mechanical properties in the cold-rolled, annealed state and after age hardening.

19

Adaptive Plasticity in Insect Parasites – Philopterus Lice and their Accentor Passerine Hosts

Janiga M.

Polish Journal of Ecology

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2018

|

Vol. 66, nr 4

395--406

EN

One hundred and five alpine accentors Prunella collaris (Scopoli, 1786) and ninety four dunnocks Prunella modularis (Linnaeus, 1758) were captured in the West Carpathian Mountains of Slovakia in order to compare the morphology of their Ischnoceran parasites Philopterus emiliae Balát 1985 and Philopterus modularis (Denny, 1842), respectively. In the case of both host species, the largest bodied lice occurred in winter, before the beginning of the host breeding season. Lice collected during the host breeding season were smaller in size than those collected in winter. Lice collected in the autumn, following postnuptial molt were even smaller in size. The largest lice were found on the bodies of host individuals with relatively long wings. The lice Ph. emiliae also differed in shape. In winter, the relative size of the head was large, while in the autumn, the head was proportionately smaller in size, compared to other body regions. Adult lice Ph. modularis also tended to have larger heads in April than in July. Measurements of lice over an eleven year period from the same site yielded differences in shape, but not in size. This study is one of the first assessments of seasonal variation in morphology of lice.

20

Material definition to design vehicle components, application to crashworthiness

Rusinek A., Zaera R.

Logistics and Transport

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2018

|

Vol. 38, No. 2

63--67

EN

In this paper a short description is reported allowing to take into account some aspects to design structures used for automotive industries. It allows to define correctly the behaviour of a vehicle and mainly the passive structures to absorb energy during an accident or an impact. The main aspect related to the behaviour is the strain rate sensitivity coupled to the process of elastic wave propagation.