This paper presents a method for modelling the permeability of fluid at the interface formed betw... more This paper presents a method for modelling the permeability of fluid at the interface formed between flat parallel plates and the sharp-edged ridges of a metal gasket. This work was divided into three stages. In the first stage, numerical calculations simulating the deformation (compression of the gasket) were performed. The calculations were carried out using thermomechanical static analysis with commercial software. The purpose of these calculations was to determine the contact area of the gasket ridges with the plates, the deformation of the gasket ridges, and the reaction force resulting from the degree of compression of the gasket. In the second part of this work, analytical calculations were performed to estimate the tightness level. The analytical model proposed in this paper was based on Darcy's equation, simulating fluid flow through a ring-shaped porous layer. The analytical model also took into account the shape of the roughness profile of the sealed surfaces. A mathematical Ausloos-Berman function based on fractal theory was used to represent it. In the last part of this work, experimental tests were carried out to determine the actual fluid permeability and thus verify the numerical and analytical calculations.
Highly efficient fiber-reinforced composites find extensive application in diverse industries. Ye... more Highly efficient fiber-reinforced composites find extensive application in diverse industries. Yet, conventional fiber-reinforced composites have significant environmental impacts during both manufacturing and disposal. Environmentally friendly fiber-reinforced composites have garnered significant attention within the framework of sustainable development. Utilizing natural fibers in place of synthetic fibers and progressively decreasing the use of synthetic fibers are the main approaches to achieving a balance between economic progress and environmental quality. At-tention is increasingly being drawn to natural fiber-reinforced biocomposites that exhibit out-standing environmental performance, exceptional physical and mechanical capabilities, and bi-ological features. The lightweight and high-strength characteristics of these biocomposites enable them to significantly decrease the weight of structures, making them increasingly popular in many industries. The objective of this review is to evaluate the effectiveness of hybrid fiber-reinforced biocomposites in marine applications, specifically examining their mechanical characteristics, resistance to seawater, and ability to absorb moisture, all while advocating for sustainable ma-terial methodologies. To achieve this objective, the paper delineates the distinction between synthetic and natural fibers, examines the benefits of hybrid fiber-reinforced biocomposite ma-terials, and addresses the obstacles and effective approaches in their production and application in seawater. Considering the review analysis, it can be inferred that the use of fiber-reinforced bi-ocomposites in maritime applications shows significant potential and has abundant untapped growth prospects in the future years.
Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a rela... more Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a rela-tively long tool life. One of the basic indices describing the susceptibility of ductile cast irons to change in volume, shape, and dimensions under machining conditions is their machinability. Machinability can be expressed directly in terms of the values of basic quantities such as periodic cutting speed and roughness. At the same time, machinability is a relative quantity evaluated alternatively. This means that the machinability of ductile cast iron can be good, allowing high cutting speeds to be achieved, but it can also be poor, expressed in terms of poor surface quality. In the experimental research carried out, an attempt was made to determine the limit values of the cutting speed, beyond which one should not exceed, in order to increase the efficiency of the machining process. The surface roughness, unlike the periodic cutting speed, is a quantity defined in the product design docu-mentation, so its limits must be observed. In addition to the usual indices of surface geometric texture, the research analysed alternative indices for determining the condition of surface geometric texture and the influence of periodic cutting speed on their values. In the conclusions, valuable recommendations are given for designers and technologists on the purpose and functionality of product surfaces and how to define them. Methods of specifying tribological characteristics, hy-drophobic or hydrophilic properties, as well as the ability to retain fluids and maintain protective coatings of ductile cast iron parts after machining are described, for which relative values, depending on the machining parameters used, can vary from about 10 to even 30%.
Finite element modelling of multi-bolted foundation connections used for the foundation of
heavy ... more Finite element modelling of multi-bolted foundation connections used for the foundation of heavy machinery or equipment is presented. Connections made using different types of shims, with particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the adopted models of multi-bolted foundation connections at the installation stage are described and compared. It is shown that the use of polymer–steel shims can result in a significant improvement in the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim, and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection with a steel shim (at a sufficiently low polymer layer thickness).
The paper presents the procedures developed to correctly assess the geometric condition of large ... more The paper presents the procedures developed to correctly assess the geometric condition of large crankshafts using a novel measurement system equipped with a specially designed prism support system with computer monitoring of support reaction forces. These procedures were developed for three variants of measurement execution corresponding to conditions: non-referenced (fixing of the shaft to be measured with the outer extremes of the faces in the spherical prisms and supporting the shaft in the central part with a set of supports referred to as ‘elastic’), referenced (fixing of the shaft to be measured by the outer extremes of the main journals in prisms and support of the crankshaft in the central part, as in the case of the previous variant, by a set of supports referred to as ‘elastic’) and realised in conditions similar to the traditional ones (fixing and support of the crankshaft by a set of prism supports maintaining a constant height position). Considering the utilitarian potential of the developed procedures, exemplary applications of their practical use in the measurement of large crankshafts are presented.
Advances in Science and Technology Research Journal, 2024
The escalating global population and subsequent demand for agricultural products have led to a su... more The escalating global population and subsequent demand for agricultural products have led to a surge in agricultural waste generation, posing significant disposal challenges. Conventional disposal methods such as burning and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable development globally.
Archives of Metallurgy and Materials, Jun 21, 2024
The subject of the paper is the modelling of multi-bolted connections that are at the pretensioni... more The subject of the paper is the modelling of multi-bolted connections that are at the pretensioning stage. taking a systematic approach to the modelling issue, the connection was treated as a composite of four subsystems: a bolt set, a pair of joined elements and a contact layer between them. the first part of the paper describes experimental studies to determine the contact stiffness of a pair of elements separated from an exemplary asymmetric multi-bolted connection. the normal loading and unloading direction of the contact joint was considered. the tests were performed with the use of an iNstRoN 8850 servo-hydraulic testing machine equipped with an extensometer. a normal stiffness characteristic in the form of an exponential function was proposed for the tested contact joint. it will be applied in the second part of the paper, in which finite element modelling of the multi-bolted connection will be presented.
The aim of this article is to investigate the effect of atmospheric conditions on the tightening ... more The aim of this article is to investigate the effect of atmospheric conditions on the tightening behaviour of HV bolts in structural bolt sets. The article describes the results of experimental tests carried out for bolt sets of a selected type. The parts of the joined sets were stored according to the specified six different conditions for four weeks before assembly. Paper, cardboard boxes and anticorrosion foils were used as protection against atmospheric conditions. The behaviour of unassembled and assembled bolt sets was also taken into account. The variation in the friction coefficient depending on the clamping force and storage conditions of the bolt sets was demonstrated. This applies both to the contact between the joining elements on the threaded surfaces and to the area between the bolt head and the bearing surface of the nut and washer.
In the past few decades, the use of agricultural waste has been increasing due to the increasing ... more In the past few decades, the use of agricultural waste has been increasing due to the increasing demand for sustainable materials. This paper aims to review the significance of agricultural waste as a type of wealth and its potential as an alternative material in the composite field. It was found that many agricultural wastes had been utilized in various production of ecological products. The review discusses the physical, mechanical, and chemical properties of the natural fibers made from agricultural waste and the use of Pineapple Leaf Fiber Reinforced Composite to manufacture UAVs (Unmanned Aerial Vehicles). The extracted waste fibers’ physical, mechanical, and chemical properties show that these agricultural wastes can produce better advanced composite materials suitable for structural applications. The use of pineapple leaf fiber in Unmanned Aerial Vehicles manufacturing has the potential to revolutionize this industry and contribute to a more sustainable future.
The main aim of the paper is to catalog ways of modeling bolted joints and introducing bolt prelo... more The main aim of the paper is to catalog ways of modeling bolted joints and introducing bolt preload using the finite element method. The paper presents models of bolted joints published in the current decade (i.e. after 1 January 2021 and up to 10 May 2023) in journals of the world's largest scientific publishers, such as: Elsevier, Springer, and MDPI, among others. Reporting of the systematic review was carried out based on PRISMA guidelines. The databases were searched with the EBSCO multi-search engine for the following keywords: bolted joint model, bolted connection model, preload, and finite element method. Additionally, the search results were narrowed down to peer-reviewed papers from the discipline of engineering and written in English. This yielded 2,712 records for further analysis. After removing duplicates from this group, screening was carried out, based on which 1,476 records were excluded from the study. For the remaining group of reports, an eligibility assessmen...
International Journal of Applied Sciences & Development
The paper presents the process of constructing and programming an automatic measurement tester th... more The paper presents the process of constructing and programming an automatic measurement tester that can be operated remotely via the Internet. The proposed innovative tester can be used for rapid and automated verification of compliance of medical device components such as power supplies. The process of writing the program supporting the measurement tester is presented and the principle of its operation is described, along with the method of generating the developed measurement results.
This paper presents the modelling of a simultaneous multiple collision occurring between several ... more This paper presents the modelling of a simultaneous multiple collision occurring between several bodies ofa kinematic chain. An algorithm is proposed that when used with an elastoplastic contact model, allows thephenomena that can occur during a multiple-body collision to be taken into account. These phenomena includethe transition of the collision state from the restitution phase directly to the compression phase or successivecollisions occurring along the same normal. The proposed algorithm can be used with any elastoplastic contactmodel. This paper presents its use with a selected model in a three-body system. Numerical calculations basedon the model have been verified using the Finite Element Method (FEM). The use of the proposed improvedapproach reduces the post-collision velocity prediction error by 2.34% compared to the baseline descriptionof collisions known from the literature.
Purpose The aim of study was to determine the influence of factors such as temperature and glutar... more Purpose The aim of study was to determine the influence of factors such as temperature and glutaraldehyde (GA) concentration on the mechanical properties of porcine pericardia, and to propose the recommended optimal conditions for a cross-linking process. It was also to verify whether tannic acid (TA), a natural cross-linking agent that stabilizes collagenous tissues by different mechanism than GA, may positively influence the strength of pericardium. Methods The samples were incubated at various temperatures (4, 22, and 37°C) and GA concentration solutions (0.6%, 1.5%, 3%) for 7 days. Three series were selected and additionally cross-linked with 0.3% TA for another 7 days. Mechanical properties of cross-linked pericardium samples, i.e. ultimate tensile strength (UTS) and elastic modulus (E), were measured in uniaxial tensile testing. The hyperelastic model for incompressible materials – isotropic by Ogden and anisotropic by Fung was utilized to describe the mechanical behaviour of ...
The paper extends the concept of cut edge quality and examines the fibre laser cutting process. A... more The paper extends the concept of cut edge quality and examines the fibre laser cutting process. A Prima Power Platino Fiber Evo device with a reference speed (RS) of 3500 mm/min was used for laser cutting. In order to analyse the influence of the laser cutting speed on the cut edge quality of X5CrNi18-10 stainless steel sheets, macroscopic studies were conducted on a stereoscopic microscope and surface stereometry on a confocal microscope. The obtained results were analysed to evaluate 2D and 3D parameters. These parameters make it possible to determine the cut edge quality and the susceptibility to the application of protective coatings. It was observed that the value of the Sa parameter is the highest for a cutting speed equal to 130% of RS. The Sz parameter is similar, while the Sk, Spk and Svk parameters rise as the speed increases, which is a negative phenomenon. Comparative tests were also conducted for four specimens made at cutting speeds of 70%, 85%, 100% and 115% of RS, re...
This paper presents a method for modelling the permeability of fluid at the interface formed betw... more This paper presents a method for modelling the permeability of fluid at the interface formed between flat parallel plates and the sharp-edged ridges of a metal gasket. This work was divided into three stages. In the first stage, numerical calculations simulating the deformation (compression of the gasket) were performed. The calculations were carried out using thermomechanical static analysis with commercial software. The purpose of these calculations was to determine the contact area of the gasket ridges with the plates, the deformation of the gasket ridges, and the reaction force resulting from the degree of compression of the gasket. In the second part of this work, analytical calculations were performed to estimate the tightness level. The analytical model proposed in this paper was based on Darcy's equation, simulating fluid flow through a ring-shaped porous layer. The analytical model also took into account the shape of the roughness profile of the sealed surfaces. A mathematical Ausloos-Berman function based on fractal theory was used to represent it. In the last part of this work, experimental tests were carried out to determine the actual fluid permeability and thus verify the numerical and analytical calculations.
Highly efficient fiber-reinforced composites find extensive application in diverse industries. Ye... more Highly efficient fiber-reinforced composites find extensive application in diverse industries. Yet, conventional fiber-reinforced composites have significant environmental impacts during both manufacturing and disposal. Environmentally friendly fiber-reinforced composites have garnered significant attention within the framework of sustainable development. Utilizing natural fibers in place of synthetic fibers and progressively decreasing the use of synthetic fibers are the main approaches to achieving a balance between economic progress and environmental quality. At-tention is increasingly being drawn to natural fiber-reinforced biocomposites that exhibit out-standing environmental performance, exceptional physical and mechanical capabilities, and bi-ological features. The lightweight and high-strength characteristics of these biocomposites enable them to significantly decrease the weight of structures, making them increasingly popular in many industries. The objective of this review is to evaluate the effectiveness of hybrid fiber-reinforced biocomposites in marine applications, specifically examining their mechanical characteristics, resistance to seawater, and ability to absorb moisture, all while advocating for sustainable ma-terial methodologies. To achieve this objective, the paper delineates the distinction between synthetic and natural fibers, examines the benefits of hybrid fiber-reinforced biocomposite ma-terials, and addresses the obstacles and effective approaches in their production and application in seawater. Considering the review analysis, it can be inferred that the use of fiber-reinforced bi-ocomposites in maritime applications shows significant potential and has abundant untapped growth prospects in the future years.
Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a rela... more Modern technology allows ductile cast iron parts to be efficiently machined while ensuring a rela-tively long tool life. One of the basic indices describing the susceptibility of ductile cast irons to change in volume, shape, and dimensions under machining conditions is their machinability. Machinability can be expressed directly in terms of the values of basic quantities such as periodic cutting speed and roughness. At the same time, machinability is a relative quantity evaluated alternatively. This means that the machinability of ductile cast iron can be good, allowing high cutting speeds to be achieved, but it can also be poor, expressed in terms of poor surface quality. In the experimental research carried out, an attempt was made to determine the limit values of the cutting speed, beyond which one should not exceed, in order to increase the efficiency of the machining process. The surface roughness, unlike the periodic cutting speed, is a quantity defined in the product design docu-mentation, so its limits must be observed. In addition to the usual indices of surface geometric texture, the research analysed alternative indices for determining the condition of surface geometric texture and the influence of periodic cutting speed on their values. In the conclusions, valuable recommendations are given for designers and technologists on the purpose and functionality of product surfaces and how to define them. Methods of specifying tribological characteristics, hy-drophobic or hydrophilic properties, as well as the ability to retain fluids and maintain protective coatings of ductile cast iron parts after machining are described, for which relative values, depending on the machining parameters used, can vary from about 10 to even 30%.
Finite element modelling of multi-bolted foundation connections used for the foundation of
heavy ... more Finite element modelling of multi-bolted foundation connections used for the foundation of heavy machinery or equipment is presented. Connections made using different types of shims, with particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the adopted models of multi-bolted foundation connections at the installation stage are described and compared. It is shown that the use of polymer–steel shims can result in a significant improvement in the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim, and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection with a steel shim (at a sufficiently low polymer layer thickness).
The paper presents the procedures developed to correctly assess the geometric condition of large ... more The paper presents the procedures developed to correctly assess the geometric condition of large crankshafts using a novel measurement system equipped with a specially designed prism support system with computer monitoring of support reaction forces. These procedures were developed for three variants of measurement execution corresponding to conditions: non-referenced (fixing of the shaft to be measured with the outer extremes of the faces in the spherical prisms and supporting the shaft in the central part with a set of supports referred to as ‘elastic’), referenced (fixing of the shaft to be measured by the outer extremes of the main journals in prisms and support of the crankshaft in the central part, as in the case of the previous variant, by a set of supports referred to as ‘elastic’) and realised in conditions similar to the traditional ones (fixing and support of the crankshaft by a set of prism supports maintaining a constant height position). Considering the utilitarian potential of the developed procedures, exemplary applications of their practical use in the measurement of large crankshafts are presented.
Advances in Science and Technology Research Journal, 2024
The escalating global population and subsequent demand for agricultural products have led to a su... more The escalating global population and subsequent demand for agricultural products have led to a surge in agricultural waste generation, posing significant disposal challenges. Conventional disposal methods such as burning and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable development globally.
Archives of Metallurgy and Materials, Jun 21, 2024
The subject of the paper is the modelling of multi-bolted connections that are at the pretensioni... more The subject of the paper is the modelling of multi-bolted connections that are at the pretensioning stage. taking a systematic approach to the modelling issue, the connection was treated as a composite of four subsystems: a bolt set, a pair of joined elements and a contact layer between them. the first part of the paper describes experimental studies to determine the contact stiffness of a pair of elements separated from an exemplary asymmetric multi-bolted connection. the normal loading and unloading direction of the contact joint was considered. the tests were performed with the use of an iNstRoN 8850 servo-hydraulic testing machine equipped with an extensometer. a normal stiffness characteristic in the form of an exponential function was proposed for the tested contact joint. it will be applied in the second part of the paper, in which finite element modelling of the multi-bolted connection will be presented.
The aim of this article is to investigate the effect of atmospheric conditions on the tightening ... more The aim of this article is to investigate the effect of atmospheric conditions on the tightening behaviour of HV bolts in structural bolt sets. The article describes the results of experimental tests carried out for bolt sets of a selected type. The parts of the joined sets were stored according to the specified six different conditions for four weeks before assembly. Paper, cardboard boxes and anticorrosion foils were used as protection against atmospheric conditions. The behaviour of unassembled and assembled bolt sets was also taken into account. The variation in the friction coefficient depending on the clamping force and storage conditions of the bolt sets was demonstrated. This applies both to the contact between the joining elements on the threaded surfaces and to the area between the bolt head and the bearing surface of the nut and washer.
In the past few decades, the use of agricultural waste has been increasing due to the increasing ... more In the past few decades, the use of agricultural waste has been increasing due to the increasing demand for sustainable materials. This paper aims to review the significance of agricultural waste as a type of wealth and its potential as an alternative material in the composite field. It was found that many agricultural wastes had been utilized in various production of ecological products. The review discusses the physical, mechanical, and chemical properties of the natural fibers made from agricultural waste and the use of Pineapple Leaf Fiber Reinforced Composite to manufacture UAVs (Unmanned Aerial Vehicles). The extracted waste fibers’ physical, mechanical, and chemical properties show that these agricultural wastes can produce better advanced composite materials suitable for structural applications. The use of pineapple leaf fiber in Unmanned Aerial Vehicles manufacturing has the potential to revolutionize this industry and contribute to a more sustainable future.
The main aim of the paper is to catalog ways of modeling bolted joints and introducing bolt prelo... more The main aim of the paper is to catalog ways of modeling bolted joints and introducing bolt preload using the finite element method. The paper presents models of bolted joints published in the current decade (i.e. after 1 January 2021 and up to 10 May 2023) in journals of the world's largest scientific publishers, such as: Elsevier, Springer, and MDPI, among others. Reporting of the systematic review was carried out based on PRISMA guidelines. The databases were searched with the EBSCO multi-search engine for the following keywords: bolted joint model, bolted connection model, preload, and finite element method. Additionally, the search results were narrowed down to peer-reviewed papers from the discipline of engineering and written in English. This yielded 2,712 records for further analysis. After removing duplicates from this group, screening was carried out, based on which 1,476 records were excluded from the study. For the remaining group of reports, an eligibility assessmen...
International Journal of Applied Sciences & Development
The paper presents the process of constructing and programming an automatic measurement tester th... more The paper presents the process of constructing and programming an automatic measurement tester that can be operated remotely via the Internet. The proposed innovative tester can be used for rapid and automated verification of compliance of medical device components such as power supplies. The process of writing the program supporting the measurement tester is presented and the principle of its operation is described, along with the method of generating the developed measurement results.
This paper presents the modelling of a simultaneous multiple collision occurring between several ... more This paper presents the modelling of a simultaneous multiple collision occurring between several bodies ofa kinematic chain. An algorithm is proposed that when used with an elastoplastic contact model, allows thephenomena that can occur during a multiple-body collision to be taken into account. These phenomena includethe transition of the collision state from the restitution phase directly to the compression phase or successivecollisions occurring along the same normal. The proposed algorithm can be used with any elastoplastic contactmodel. This paper presents its use with a selected model in a three-body system. Numerical calculations basedon the model have been verified using the Finite Element Method (FEM). The use of the proposed improvedapproach reduces the post-collision velocity prediction error by 2.34% compared to the baseline descriptionof collisions known from the literature.
Purpose The aim of study was to determine the influence of factors such as temperature and glutar... more Purpose The aim of study was to determine the influence of factors such as temperature and glutaraldehyde (GA) concentration on the mechanical properties of porcine pericardia, and to propose the recommended optimal conditions for a cross-linking process. It was also to verify whether tannic acid (TA), a natural cross-linking agent that stabilizes collagenous tissues by different mechanism than GA, may positively influence the strength of pericardium. Methods The samples were incubated at various temperatures (4, 22, and 37°C) and GA concentration solutions (0.6%, 1.5%, 3%) for 7 days. Three series were selected and additionally cross-linked with 0.3% TA for another 7 days. Mechanical properties of cross-linked pericardium samples, i.e. ultimate tensile strength (UTS) and elastic modulus (E), were measured in uniaxial tensile testing. The hyperelastic model for incompressible materials – isotropic by Ogden and anisotropic by Fung was utilized to describe the mechanical behaviour of ...
The paper extends the concept of cut edge quality and examines the fibre laser cutting process. A... more The paper extends the concept of cut edge quality and examines the fibre laser cutting process. A Prima Power Platino Fiber Evo device with a reference speed (RS) of 3500 mm/min was used for laser cutting. In order to analyse the influence of the laser cutting speed on the cut edge quality of X5CrNi18-10 stainless steel sheets, macroscopic studies were conducted on a stereoscopic microscope and surface stereometry on a confocal microscope. The obtained results were analysed to evaluate 2D and 3D parameters. These parameters make it possible to determine the cut edge quality and the susceptibility to the application of protective coatings. It was observed that the value of the Sa parameter is the highest for a cutting speed equal to 130% of RS. The Sz parameter is similar, while the Sk, Spk and Svk parameters rise as the speed increases, which is a negative phenomenon. Comparative tests were also conducted for four specimens made at cutting speeds of 70%, 85%, 100% and 115% of RS, re...
Proc. of the XXXI International Conference CAD in Machinery Design Implementation and Educational Issues (Supraśl, Poland, 26-28 X 2023), 2024
The paper deals with the modelling of multi-bolted connections under preload conditions in a syst... more The paper deals with the modelling of multi-bolted connections under preload conditions in a systemic approach. A modelling procedure based on the finite element method is presented. According to it, the connection was treated as a combination of four subsystems: a bolt-nut set, a pair of joined components and a contact layer between them. The contact layer model used allows the actual mechanical properties of the contact joint to be taken into account. The application of the method is illustrated using the example of an asymmetric connection. First, its solid model was built, followed by a discrete model in which the bolt-nut set was replaced by a hybrid model with a non-deformable bolt head and nut and a deformable bolt shank. Finally, selected results of connection calculations are also provided. The utilitarian relevance of a systemic approach to modelling multi-bolted connections and the opportunities it delivers for connection assessment is presented.
Fundamentals of machine design. Selected problems, 2020
The paper is related to modeling of multi-bolted connections treated as a system in the assembly ... more The paper is related to modeling of multi-bolted connections treated as a system in the assembly state. The model of the connection with various models of the contact layer between joined elements is presented. The system has been pretensioned in accordance with the specified tightening sequence of bolts and in several tightening cycles. Sample calculations were made for the selected asymmetrical flange connection. As a result of these calculations, the preload distributions in one of the bolts are shown.
The paper is related to modeling of multi-bolted joints treated as a system. The model of the joi... more The paper is related to modeling of multi-bolted joints treated as a system. The model of the joint with various substitute models of bolts is presented. The system was pre-tensioned and externally loaded with normal forces. Calculations were made for an exemplary asymmetric joint. As a result of these calculations, distributions of operational forces in the bolts are shown.
IEEE Conferences, Proc. of the 2018 International Interdisciplinary PhD Workshop (IIPhDW 2018) (Świnoujście, Poland, 9-12 May 2018), Szczecin, ZUT w Szczecinie 2018, 2018
Modelling and calculations of a bolted flange connection located under elevated temperature condi... more Modelling and calculations of a bolted flange connection located under elevated temperature conditions are presented. Analysis of forces acting on the bolt and the joined elements on the basis of analytical formulas and using the finite element method (FEM) is performed. In the case of theoretical calculations the recommendations given in books on the fundamentals of machine design are applied. For a case of numerical calculations a simplified model of the bolt is used. The obtained results of calculations are checked in terms of fulfilment of the adopted strength criterion associated with acceptable thermal stress in the bolt. Selected results of simulation studies of the connection FEM-model in the form of temperature distribution in the model are shown. On the basis of the comparison of the theoretical and numerical analyses results, the usefulness of the simplified bolt model for calculations of forces in the bolts in flange connections under elevated temperature conditions is determined.
Proc. of the 22nd International Scientific Conference “MECHANIKA 2017“ (Birštonas, Lithuania, 19 May 2017), Kaunas, Kaunas University of Technology 2017, 114-117.
The paper deals with modelling and calculations of a contact layer between elements joined in a m... more The paper deals with modelling and calculations of a contact layer between elements joined in a multi-bolted joint for the assembly condition. The physical mod-el of the multi-bolted joint is based on a system consisting of a flexible flange element that is joined with a flexible support by means of the rigid body bolt model. The contact layer between joined elements is described as the nonlinear Winkler model. The contact joint model considering an experimental normal elastic characteristic is presented. Examples of normal contact pressure distributions are contained.
Proc. of the 22nd International Scientific Conference “MECHANIKA 2017“ (Birštonas, Lithuania, 19 May 2017), Kaunas, Kaunas University of Technology 2017, 110-113.
The paper deals with modelling and calculations of asymmetrical multi-bolted joints treated as a ... more The paper deals with modelling and calculations of asymmetrical multi-bolted joints treated as a system composed of four subsystems at the assembly stage. These subsystems are: a couple of joined elements, a contact layer between the elements, and a set of bolts. The contact layer is formed as the Winkler model, and the set of bolts are modeled using simplified beam models. The truth of the theorem has been tested, according to which nonlinearity of the contact layer has a negligible impact on the final values of the bolt forces in the case of sequential tightening of the multi-bolted joint.
The theme of the paper is to determine effective methods of contemporary building structures vibr... more The theme of the paper is to determine effective methods of contemporary building structures vibration analysis. The results of application of the experimental modal analysis in order to assign the modal parameters of the model, mapping a typical column-beam-plate structure founded on a rigid base, is presented. The study is carried out in the form of a impulse test. Based on the test results analysis modal parameters of the model as a set of natural frequencies and corresponding mode shapes as well as modal attenuation coefficients are estimated. The model is validated using the MAC (Modal Assurance Criterion).
Palenica P., Powałka B., Grzejda R.: Assessment of modal parameters of a building structure model, Springer Proceedings in Mathematics & Statistics, vol. 181, 319-325., Sep 2016
This paper relates to the field of vibrations of contemporary building structures. The aim of thi... more This paper relates to the field of vibrations of contemporary building structures. The aim of this study is to develop methods to estimate the safety of use of buildings subjected to dynamic loads. Calculations are carried out based on selected computational models of the column-beam-plate system used at the design stage of monolithic building structures. For modeling, the finite element method (FEM) is used. The results of calculations are compared with laboratory tests of the special model mapping of a building structure.
Grzejda R.: Comparative analysis of selected methods for seating of machines using foundation bolted joints, Proc. of the XXV International Conference on Theory of Machines and Mechatronic Systems (Nowy Sącz – Rytro, Poland, 18-21 IX 2016), Sep 18, 2016
Finite element modelling of foundation bolted joints applied in the case of seating of heavy mach... more Finite element modelling of foundation bolted joints applied in the case of seating of heavy machines or devices is presented. The joints made with the use of three different types of chocks are examined. Stiffness characteristics for the adopted models of the foundation bolted joint at the assembly stage are described and compared. Conclusions of paramount importance to the engineering practice are created.
Proc. of the 15th International Scientific Conference “Engineering for Rural Development 2016“ (Jelgava, Latvia, 25-27 May 2016), Jelgava, Latvia University of Agriculture 2016, 336-341.
The report deals with modelling and calculations of asymmetrical multi-bolted connections at the ... more The report deals with modelling and calculations of asymmetrical multi-bolted connections at the operational stage. The physical model of the joint is based on a flexible flange element that is connected with a rigid support by means of the spider bolt models. Between the joined elements the nonlinear Winkler model of a contact layer is taken into consideration. A computational model of the system is proposed, which makes it possible to analyze any preloaded multi-bolted connection subjected to an eccentric normal load. The sample results obtained from the calculations are presented.
Proc. of the 15th International Scientific Conference “Engineering for Rural Development 2016“ (Jelgava, Latvia, 25-27 May 2016), Jelgava, Latvia University of Agriculture 2016, 329-335.
The article deals with modelling and calculations of asymmetrical multi-bolted connections at the... more The article deals with modelling and calculations of asymmetrical multi-bolted connections at the assembly stage. The physical model of the joint is based on a flexible flange element that is connected with a rigid support by means of the spider bolt models. Between the joined elements the nonlinear Winkler model of a contact layer is taken into consideration. A computational model of the system is proposed, which makes it possible to analyze how the tightening sequence affects the distribution of preload both during the multi-bolted connection assembly and after it has been completed. The sample results obtained from the calculations are presented.
Advances in Mechanics: Theoretical, Computational and Interdisciplinary Issues, Proc. of the 3rd Polish Congress of Mechanics (PCM) and 21st International Conference on Computer Methods in Mechanics (CMM) (Gdansk, Poland, 8-11 September 2015), Leiden, CRC Press/Balkema 2016, 213-216.
Multi-bolted connections are systems of many bodies being in a contact. These systems are compose... more Multi-bolted connections are systems of many bodies being in a contact. These systems are composed of: fasteners, joined elements and contact joints between them. There are known methods for modelling and calculation of parts of typical multi-bolted connections, which are geometrically symmetrical or symmetrically loaded. A novelty is a treatment of the multi-bolted connection as a system consisting of components, which can be considered, modelled and calculateted as separate subsystems using methods adequate to their properties. The aim of this paper is to present the concept of a new modelling method of multi-bolted connections dealing with as multi-bolted systems. The model assumptions and modelling bases of separate subsystems of a physical model of the multi-bolted connection are given. The outcome of actions described in this paper is establishment of the equilibrium equations, which can be applied for any condition of the multi-bolted system. Calculations results of a selected multi-bolted connection are presented.
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Papers by Rafał Grzejda
heavy machinery or equipment is presented. Connections made using different types of shims, with
particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the
adopted models of multi-bolted foundation connections at the installation stage are described and
compared. It is shown that the use of polymer–steel shims can result in a significant improvement in
the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim,
and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection
with a steel shim (at a sufficiently low polymer layer thickness).
and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural
plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural
plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current
disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple
leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its
exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for
a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and
environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable
development globally.
heavy machinery or equipment is presented. Connections made using different types of shims, with
particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the
adopted models of multi-bolted foundation connections at the installation stage are described and
compared. It is shown that the use of polymer–steel shims can result in a significant improvement in
the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim,
and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection
with a steel shim (at a sufficiently low polymer layer thickness).
and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural
plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural
plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current
disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple
leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its
exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for
a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and
environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable
development globally.