Wyniki wyszukiwania - BazTech

1

Assessment of the influence of the bending form shape on the stress and plastic strain values in a cold bending pipe

Nozdrzykowski Krzysztof, Stępień Mateusz, Grządziel Zenon

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2024

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nr 78 (150)

35--48

EN

Abstract This paper presents the results of modelling research concerned with the technological process of the cold bending of a pipe. Stress and plastic strain studies are carried out using the finite element method (FEM) on a thick-walled pipe and various shapes of bending form. The results of the research are benchmarked in terms of the correctness of the implementation of the bending process, including the change in the pipe outside diameter and wall thickness. The level of ovalisation of the cross-section in the bending pipe is used as the primary criterion for assessing the correctness of the bending process. The results show that the most favourable properties in terms of minimising the ovalisation of the pipe cross-section are provided by the use of a bending form with a trapezoidal shape.

2

Innovative FEM for the thermal analysis of architectural glazing exposed to solar radiation. Proposal for a simplified engineering approach

Galuppi Laura, Maffeis Massimo, Haydar Ali, Royer-Carfagni Gianni

Świat Szkła

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2024

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R. 29, nr 9

2--g

3

Problem modelowania przestrzennych konstrukcji drewnianych z masywnego drewna z wykorzystaniem modeli prętowych

Janas Agnieszka, Brol Janusz

Przegląd Budowlany

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2024

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R. 95, nr 3

34--38

PL

W artykule przedstawiono problem właściwego odzwierciedlenia w modelowaniu komputerowym z wykorzystaniem elementów prętowych, drewnianych schodów spiralnych jako elementów z belek drewnianych ułożonych wzajemnie na sobie. Podano sposób rozwiązania tego zagadnienia przez autorów artykułu na przykładzie dyplomowej pracy inżynierskiej pt.: „Projekt wieży widokowej o konstrukcji drewnianej” [1] wykonanej przez autorkę artykułu.

EN

The article presents the problem of proper representation, in computer modelling using bar elements, of wooden spiral stairs as elements made of wooden beams stacked on top of each other. The method of solving this issue by the authors of the article is presented on the example of the engineering diploma thesis titled: „Design of an observation tower with a wooden structure” [1] prepared by the author of the article.

4

Results of stress measurements on the guide rail supporting beams in a hoisting installation operated in the shaft Regis in relation to modelling data

Rozwadowski Krzysztof, Konewecki Artur, Pasek Rafał, Molski Szymon

Mining Machines

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2024

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vol. 42, iss. 2

90--107

EN

Presently the hoisting installation operated in the Wieliczka Salt Mine is mostly used for transporting visitors to the underground mine sections. It comprises two elevators which are able to effectively transport groups of up to 42 people during a single ride. Design objectives developed prior to its mounting at the shaft bottom and observations made by maintenance engineers clearly indicate that the guiding system in the shaft is very stiff and so deformations are in fact negligible. The components of the guiding system which have the highest stiffness are bunton beams, designed in accordance with pertinent regulations having relevance to hoisting installations.To verify the rationale of implementing the stiff steelwork frame, the digital model of the steelwork frame was created and numerical procedures were applied, taking into account the maximal design loads and operational loads. Numerical results were validated through measurements of real stress values at selected components of the guiding system in the hoisting installation operated in the shaft “Regis’, under variable operating conditions. The analysis of measurement data allows a preliminary evaluation of structural parameters of the car frame, highlighting the potential of reducing the mass of components selected to be optimised.

5

Optimization of the topology of the structural component of a magnetic robot

Pac Paweł, Prostański Dariusz

Mining Machines

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2024

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vol. 42, iss. 1

30--48

EN

The article focuses on topology optimization using the Finite Element Method (FEM) in the context of mechanical design and structural engineering. The analysis was based on a robotarm component, which is important for minimising its mass due to the way it moves on steel structures such as mining shaft towers. FEA simulations of the non-optimized workpiece were carried out, followed by iterative mass reduction of the workpiece by editing its geometry. Two approaches were compared: manual weight reduction by the designer and topology optimization using the Shape Generator. The presented results answer the question posed in the introduction whether topology optimization using the Shape Generator can yield better results than manual optimization based on the engineering intuition of an experienced designer. The paper also answers the question of at which stage of design it is betterto use tools such as the shape generator. It is confirmed that topologyoptimization can significantly reduce the weight of the designed component, which is important especially for structures subject to special requirements, such as in the case of equipment used in mining. The authors describe what the effectiveness of the optimization may depend on.

6

Modernisation of the drop forging process on the example of forming a bracket forging

Pater Zbigniew

Mechanik

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2024

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R. 97, nr 3

6--10

EN

This paper presents an example of the manufacturing of bracket forgings formed in a dual system. Cross-wedge rolling (CWR) was proposed as the forming method for the preform. The correctness of the adopted solution was verified in numerical simulations, which were performed using the commercial software Forge®. It was shown in detail how the shape of the workpiece changes in the individual operations of the forming process. Maps of temperature, effective strain, strain rate in the preform as well as distributions of force parameters in the rolling process are presented.

PL

W artykule przedstawiono przykład wykonywania odkuwek wspornika kształtowanych w układzie podwójnym. Jako metodę wytwarzania przedkuwki zaproponowano walcowanie poprzeczno-klinowe (WPK). Poprawność przyjętego rozwiązania zweryfikowano w symulacjach numerycznych, które wykonano w komercyjnym programie Forge®. Szczegółowo pokazano, jak zmienia się kształt przedmiotu obrabianego w poszczególnych operacjach procesu kształtowania. Przedstawiono mapy temperatury, intensywności odkształcenia, prędkości odkształcenia w przedkuwce oraz rozkłady parametrów siłowych w procesie walcowania.

7

Zastosowanie MES do oceny degradacji rur stalowych

Duszyńska Iwona, Krykowski Tomasz, Gremza Grzegorz, Stefanek Paweł, Bzówka Joanna

Materiały Budowlane

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2024

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nr 4

82--85

8

Wpływ ciśnienia spływowego wody na stateczność skarp i zboczy

Łupieżowiec Marian

Materiały Budowlane

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2024

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nr 8

24--31

PL

Bardzo częstym powodem utraty stateczności skarp i zboczy jest ciśnienie wody pojawiające się wskutek warunków atmosferycznych lub zmiany filtracji wody w podłożu. Siła będąca skutkiem tego ciśnienia przeważnie stanowi jeden z głównych czynników inicjujących utratę stateczności, na którą ma wpływ również zmiana poziomu wody w zboczu po wystąpieniu ulewnych deszczy. Stateczność z uwzględnieniem oddziaływania wody można symulować metodą elementów skończonych, stosując metodę redukcji c – φ.

EN

A very common reason for the loss of stability of slopes is water pressure resulting from weather conditions or changes in water filtration in the ground. The force resulting from these pressures is usually one of the main factors initiating the loss of stability. Stability is also influenced by changes in the water level in the slope after heavy rains. Stability taking into account the impact of water can be simulated using the finite element method using the c – φ reduction method.

9

Evaluation of cracking risk of 80MnSi8-6 nanobainitic steel during hot forging in the range of lower temperature limits

Lisiecka-Graca Paulina, Lisiecki Łukasz, Zyguła Krystian, Wojtaszek Marek

Materials Science Poland

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2024

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Vol. 42, No. 1

171--185

EN

Nanobainitic steels exhibit an exceptional combination of high strength, good plasticity, impact toughness, and wear resistance. They are suitable for the production of large mass components through the open-die forging process. Subsequently, the forgings are air-cooled. An obstacle of this method is the extended time required for the large forgings to undergo a bainitic transformation, making the industrial implementation of this process economically unjustifiable. Nevertheless, nanobainitic steels also allow for the open-die forging of small batches of structural elements with high property requirements. A technological limitation lies in the necessity of performing a series of operations, leading to a prolonged processing time dependent on the shape of the product and the degree of deformation. Therefore, inter-operational reheating is often necessary, incurring costs and time consumption. This is particularly relevant to forgings with a mass ranging from a few to several dozen kilograms, which, due to their low thermal capacity, rapidly dissipate heat to the surroundings and tools. Designing an economical process with a limited number of reheating cycles requires advanced knowledge of material behavior under thermo-mechanical deformation parameters, including boundary conditions where a significant decrease in plasticity occurs and the risk of crack initiation. To obtain this information, a comprehensive analysis of the influence of thermo-mechanical parameters applied during the deformation of nanobainitic steel at relatively low temperatures on the flow characteristics and crack formation was conducted. To achieve this goal, the Digital Image Correlation method, the finite element method modeling considering damage criteria, and the macrostructural evaluation of deformed specimens were employed.

10

Optimization and modelling of fracture height in SECC cylindrical cup deep drawing processes

Trieu Quy-Huy, Luyen The-Thanh, Nguyen Duc-Toan

Journal of Machine Engineering

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2024

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Vol. 24, No. 1

74--86

EN

Deep drawing processes play a pivotal role in the manufacturing of sheet and shell products, making it a widely adopted method. This research employs numerical simulations to investigate the impact of various process parameters on the fracture height of cylindrical cups made from SECC (Steel Electrogalvanized Commercial Cold rolled) material. Specifically, it examines parameters such as blank holder force (BHF), punch corner radius (Rp), die corner radius (Rd), and punch-die clearance (Wc). The study extends to optimizing fracture height, offering a solution to this challenge. Subsequently, the selected parameters are validated through experimental deep drawing of cylindrical cups, resulting in a minimal deviation of 1.55% between simulation and experiment outcomes. A precise mathematical equation is developed to estimate fracture height under diverse machining conditions, with a maximum deviation of 4.52% observed between the mathematical model and simulation. These findings represent a substantial advancement in deep drawing processes technology, particularly in reducing error rates during the production of cylindrical cups.

11

Modelowanie i walidacja wytrzymałościowa przegrody budowlanej w zabudowie szkieletowej

Gołębiowski Łukasz, Teodorczyk Michał, Fedorczyk Zbigniew, Piekarczuk Artur

Inżynieria i Budownictwo

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2024

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R. 80, nr 4

239--242

PL

W artykule zaprezentowano badania doświadczalne i analizy numeryczne przegród w zabudowie szkieletowej. Przedmiotem analizy były elementy badawcze reprezentujące fragment przegrody składającej się z profili stalowych zimnogiętych oraz okładzin gipsowo-kartonowych. Przeprowadzono test wytrzymałości w układzie czteropunktowego zginania, w którym rejestrowano ciągły zapis obciążenia od przemieszczenia elementu. Badania prowadzono do momentu zniszczenia. Następnie opracowano model obliczeniowy bazujący na metodzie elementów skończonych (MES), odwzorowujący doświadczenie. Wyniki badań uzyskane w doświadczalnym teście wytrzymałościowym porównano z wynikami uzyskanymi w analizie numerycznej. Przeprowadzona walidacja modelu numerycznego wykazała dużą zgodność w zakresie charakterystyki obciążenia od przemieszczenia. Zastosowanie analiz numerycznych stanowi alternatywę dla czasochłonnych badań doświadczalnych przy szacowaniu przemieszczeń przegród w zabudowie szkieletowej.

EN

The article presents experimental research and numerical analysis of a building partition in frame construction. The subject of the analysis were sections of the building partition consisting of cold-bent steel profiles and plasterboard cladding. The experiment was carried out using a four-point bending test and recording a continuous load-displacement curve until failure. Next, a computational model based on the finite element method was developed to simulate the experiment. The results from the experimental tests were then compared with that obtained from the numerical analysis. The validation of the numerical model demonstrated a high level of agreement in terms of load-displacement characteristics. The use of numerical analyses provides an alternative to time-consuming experimental tests for estimating displacements of building partitions in frame construction.

12

Investigation of novel ceramic materials (Al2O3 and SSiC) for high-pressure pumps delivery sections

Idzior Marek, Karpiuk Wojciech, Smolec Rafał

Combustion Engines

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2024

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R. 63, nr 1

153--160

EN

In this paper, a comparative analysis of structural materials used in the construction of high-pressure pumps delivery sections was carried out. The focus was on a comparison of the ceramic materials such as corundum (alumina, Al2O3) and silicon carbide (solid-state sintered) - SSiC with bearing alloy steel 100Cr6, that is the most common material used to make pistons and cylinders of the delivery section of common rail injection pumps. Simulations performed using the finite element method have proven that ceramic materials have a number of advantages and could therefore be an interesting substitute for materials traditionally used in this area.

13

A Set of Finite Elements for 2D Analysis of Reinforced Concrete Foundations on Deformable Subsoil

Szajna Waldemar

Civil and Environmental Engineering Reports

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2024

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Vol. 34, no. 2

100--116

EN

The paper presents a formulation and verification of a 2D soil – structure interaction model which enables the analysis of reinforced concrete shallow foundations under monotonic short-time loads. The structure supported by a deformable subsoil, whose elasto-plastic features are being considered. The structure model describes: the ability of crack creation, non-linear stress – strain characteristics of concrete and reinforcement and also reinforcement – concrete interaction. The foundation – subsoil contact model enables the identification of slide and adhesion zones. The presented mathematical formulation allowed for the development of a set of finite elements simulating the behaviour of the foundation, the subsoil and the contact zone between them. The elasto-plastic approach was used to describe the behaviour of the structure, the subsoil and the contact phenomena. Computer programs were prepared and verifying analyses were presented.

14

Wpływ zmian temperatury na stan przemieszczeń i naprężeń w płycie betonowej

Mackiewicz Piotr, Szydło Antoni

Budownictwo, Technologie, Architektura

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2024

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nr 3

46--51

PL

Oddziaływanie temperatury w ciągu doby powoduje istotne zmiany w odkształcaniu się płyt betonowych wbudowanych w nawierzchnie drogowe. W związku z rozszerzalnością termiczną oraz nierównomiernym oddziaływaniem temperatury, płyta betonowa odkształca się w ciągu doby w zależności od różnych warunków jej posadowienia. Związane jest to z różnymi typami warstw oraz stanem podłoża, na którym spoczywa płyta. W Polsce, z uwagi na częste zmienne warunki pogodowe, nawierzchnie betonowe poddawane są cyklicznym oraz zróżnicowanym odziaływaniom termicznym w ciągu roku i doby. W artykule przeanalizowano wpływ różnych warunków podparcia płyty na stan przemieszczeń i naprężeń w analizowanym układzie warstwowym. Obliczenia numeryczne przeprowadzono w zależności od zmiennej temperatury dobowej z wykorzystaniem Metody Elementów Skończonych (MES). Z obliczeń wynika, że na skutek dobowych zmian temperatury w obszarze szczelin poprzecznych w podbudowie mogą pojawić się skumulowane przemieszczenia pionowe oraz naprężenia rozciągające prowadzące do uszkodzenia nawierzchni. Wykazano, że stosowanie sztywnych podbudów prowadzi do powstawania większych naprężeń rozciągających w płycie niż dla podbudów podatnych. Natomiast w podbudowach podatnych o małym module sztywności i dodatkowo o małej grubości będą pojawiać się skumulowane przemieszczenia. Pokazano wpływ zmiany wartości modułów i podłoża na wartości termicznych naprężeń rozciągających w płycie betonowej. Stwierdzono, że nawet niewielka zmiana grubości płyty w zakresie 5 cm w specyficznych warunkach może powodować zmiany w odkształceniach i naprężeniach. Przeprowadzone analizy mogą być pomocne przy projektowaniu nowych nawierzchni betonowych jak również ocenie nośności nawierzchni istniejących spoczywających na różnorodnych podłożach.

EN

The impact of temperature over the course of a day causes significant changes in the deformation of concrete slabs embedded in road pavements. Due to thermal expansion and uneven temperature effects, a concrete slab deforms over the course of a day depending on the different conditions of its foundation. This is related to the different types of layers and the condition of the substrate on which the slab rests. In Poland, due to frequent changing weather conditions, concrete pavements are subjected to cyclic and varying thermal actions throughout the year and day. This paper analyzes the effect of different slab support conditions on the state of displacements and stresses in the analyzed pavement system. Numerical calculations were carried out as a function of varying diurnal temperature using the Finite Element Method (FEM). The calculations show that due to diurnal temperature changes, cumulative vertical displacements and tensile stresses leading to pavement failure can occur in the area of transverse cracks in the substructure. It has been shown that the use of rigid substructures leads to higher tensile stresses in the slab than for susceptible substructures. On the other hand, cumulative displacements will occur in susceptible substructures with a low modulus of stiffness and, in addition, a low thickness. The effect of changing modulus and substructure values on the values of thermal tensile stresses in a concrete slab is shown. It was found that even a small change in slab thickness in the range of 5 cm under specific conditions can cause changes in deformations and stresses. The analyses carried out can be helpful in designing new concrete pavements as well as in evaluating the load-bearing capacity of existing pavements resting on a variety of substrates.

15

The Effect of Energy Components Modifications on the Crashworthiness of Thin-Walled Structures

Rogala Michał, Gajewski Jakub

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 6

110--120

EN

Thin-walled structures that serve as energy absorbers are widely used in the automotive industry, and it is well-known that they deform in a specific way under dynamic loading, forming plastic hinges along the yield line. The dynamic impact of these structures causes various phenomena that affect the formation of folds and, consequently, the dynamic response of the structure. The force-shortening curve, which is based on the unified crush efficiency indicators, is a key factor in determining the dynamic response of the structure. While there have been many studies on energy absorbers under static or quasi-static loading conditions, the effect of changing kinetic energy components (mass and velocity) on the obtained crush efficiency indicators is not as well understood. This article presents the results of experimental tests and nonlinear numerical simulations for eleven different initial conditions of the crashworthiness analysis. The tests showed a significant effect of changing the velocity and mass of the striker on the results obtained. Additionally, the nonlinear effect of the change in the velocity of the tup with respect to the peak force and total efficiency was demonstrated.

16

Numerical Study of Rotary Friction Welding of Automotive Components

Więckowski Wojciech, Lacki Piotr, Derlatka Anna, Wieczorek Paweł

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 4

336--346

EN

The aim of the research was to select a material from which a washer can be made, so that it can be connected to an E355 steel tube by Rotary Friction Welding (RFW). It was decided to choose the steel grade X6CrMo17-1. The numerical model of the RFW process was built using the finite element method (FEM) using the ADINA System software. The numerical model takes into account the friction coefficient with variable values depending on the temperature. Numerical simulations of the process made it possible to determine the temperature fields in the weld cross-section. For the assumed process parameters: rotational speed of 14,000 rpm, friction time of 1.5 s and friction force of 600 N, the peak temperature occurred in the middle of the friction surface at the end of the friction phase and amounted to 1050 C. The results of the temperature analysis are one of the most important parameters for the implementation of subsequent calculations, such as the calculation of structural changes, hardness, residual stresses and deformations.

17

Numerical Modelling of a Rotary Compression Test on a Cylindrical Specimen

Pater Zbigniew

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 4

23--32

EN

This paper reviews studies on the modelling of the Mannesmann effect, which leads to the formation of an axial crack in parts formed by cross and skew rolling. This effect also occurs in the rotational compression (RC) test of a cylindrical specimen, which is used to determine the critical damage value. RC tests were carried out under laboratory conditions at the Lublin University of Technology on C45 steel specimens formed at 950°C. Based on the tests, the crack propagation was presented as a function of the progress of rotational compression, measured by the length of the deformation path. The RC tests were numerically modelled in Forge® using four ductile fracture criteria. The effectiveness of the Mannesmann effect modelling was evaluated by comparing the numerically predicted cracks with the experimentally determined ones. In addition, the influence of an occurring axial crack on the stress state in the forming specimen was analysed.

18

Numerical Analysis of Selected Variants of Reinforcements of Thin-Walled Open Load-Bearing Structures Subjected to Torsion

Kopecki Tomasz

Advances in Science and Technology. Research Journal

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2024

|

Vol. 18, no 4

400--409

EN

The study concerns the comparative analysis of selected solutions of thin-walled structures subjected to constrained torsion, representing the simulation of wing areas weakened by large cutouts. The chosen variants of stiffening were based on the concept of so-called "Misztal torsion box", used in the wing of the PZL-37 aircraft. A series of numerical analyses were conducted, aiming to compare selected variants of structures with reinforcements and a reference structure based on a traditional design scheme. The calculations were performed using software based on the finite element method. An analysis of the stress and displacement distribution of the examined structure was conducted, and the results demonstrating the advantages of the proposed structural solution were presented.

19

Influence of Size of Open Hole on Stability of Compressed Plate Made of Carbon Fiber Reinforced Polymer

Wysmulski Paweł, Mieczkowski Grzegorz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

238--247

EN

This manuscript concerns the investigation of the influence of the open hole on stability of the compression plate made of carbon-epoxy composite. Experimental tests carried out on the real plate resulted in a postcritical path from which the critical load value was determined using appropriate approximation method. In parallel, an independent study was carried out based on a numerical analysis using the finite element method (FEM). Investigations were conducted in terms of a linear eigenproblem analysis, from which the value of the bifurcation load was determined for the FEM model of the plate. Its values resulting from the numerical analyses were validated against the experimental results, thus confirming the adequacy of the designed FEM model of the plate. The paper shows that the incremental increase of the hole in the plate monotonically influences the decrease in the critical load of the plate. The largest decrease was observed for the specimen with the largest hole analysed and was 13.5% compared to a plate without a hole. The newness of the paper is the application of interdisciplinary investigation methods to describe the influence of the open hole compression (OHC) on the stability of composite plates. ABAQUS® was used as the tool with which the numerical analyses were realised.

20

Forging of a Hollow Ball Using a Deformable Insert Assembly

Samołyk Grzegorz

Advances in Science and Technology. Research Journal

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2024

|

Vol. 18, no 5

32--40

EN

The paper presents selected results of numerical analysis and experimental verification. The subject is the analysis of cold forging of a thin-walled hollow ball. The process of making a ball out of aluminum alloy and steel is considered. A distinctive feature of this process is the use of a special deformable insert assembly. It consists of two shaped expanding tubes, a distance ring and a centering tube. Each of these elements has a specific function, which is characterized in this article. FEA simulation allowed proving the functionality of the insert assembly and comparing the cold forging of a steel and aluminum part, using the same inserts. Attention was also focused on the impact of the accuracy of the positioning of the insert assembly. Experimental verification confirmed the correctness of the modeling and complemented the results from FEA analysis.