Bulletin of the Polish Academy of Sciences-Technical Sciences最新文献

{"title":"Mechanical properties and geometric accuracy of angle-shaped parts manufactured using the FFF method","authors":"Wiesław Kuczko, A. Hamrol, Radosław Wichniarek, F. Górski, M. Rogalewicz","doi":"10.24425/BPASTS.2021.137387","DOIUrl":"https://doi.org/10.24425/BPASTS.2021.137387","url":null,"abstract":"Additive manufacturing (AM), also known as 3D printing, allows the shaping of parts with a complex geometry without the need for additional technological equipment [1]. Moreover, a broad spectrum of additive manufacturing varieties makes it possible to manufacture parts from many types of materials [2]. However, concerning traditional technologies (casting, machining and plastics moulding), AM has significant constraints relating to its efficiency and the quality and, above all, the physical and chemical properties of the manufactured parts [3]. Therefore, the scope of AM applications in the industrial production of everyday products is still relatively limited [4]. For most types of AM methods, especially those in which metal alloys are not used, production is focused mainly on prototypes and visual supplies [5], some types of tooling [6] and simple parts which are not heavy-duty [7]. One of the most commonly used additive manufacturing methods is FFF (Fused Filament Fabrication), also known as FDM (Fused Deposition Modelling). In this method, the physical version of a part is made from thermoplastic material. The production itself consists of applying plasticized material extruded through a nozzle with a circular end section, moving along the X and Y axis, parallel to the print bed, which is often enclosed in a chamber (see Fig. 1). After applying the material within one layer, the print bed moves its position relative to the head along the Z axis, at a value corresponding to the defined thickness of a single layer. The FDM technological parameters are related to the parts manufactured (product parameters) and to the process of mateMATERIAL SCIENCE AND NANOTECHNOLOGY","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88978019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrides precipitation in Ti6Al4V titanium alloy used for airframe manufacturing","authors":"D. Băilă, S. Tonoiu","doi":"10.24425/BPASTS.2019.129662","DOIUrl":"https://doi.org/10.24425/BPASTS.2019.129662","url":null,"abstract":". The aeronautical industry is a sector constantly looking for new materials and equipment because of its tendency to expand quickly. The Ti6Al4V titanium alloy is used frequently in the aeronautic, aerospace, automobile, chemical and medical industry because it presents high strength combined with low density ( approximately 4.5 g / cm 3 ) , good creep resistance ( up to 550°C ) , excellent corrosion resistance, high flexibility, good fatigue and biocompatibility. As a result of these properties, this titanium alloy is considered an excellent material for manufacturing structural parts in the aircraft industry for modern aeronautic structures, especially for airframes and aero-engines. But its use is also problematic because the Ti6Al4V titanium alloy manifests hydrogen embrittlement, by means of hydrides precipitation in the metal. The Ti6Al4V alloy becomes brittle and fractures because of hydrogen diffusion into metal and because titanium hydrides appear and create pres-sure from within the metal, thus generating corrosion. Because of titanium hydrides, the titanium alloy suffers from reduced ductility, tensile strength and toughness, which can result in fractures of aeronautical parts. This poses a very serious problem for aircrafts. In this paper, rapid hydrogen embrittlement is presented along with XRD, SEM and TEM analysis. Its goal is to detect the presence of titanium hydrides and to spot the initial cracks in the metallic material.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83627415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PMSM drive with adaptive state feedback speed controller","authors":"Rafał Szczepański, T. Tarczewski, L. Grzesiak","doi":"10.24425/BPASTS.2020.134624","DOIUrl":"https://doi.org/10.24425/BPASTS.2020.134624","url":null,"abstract":"In this paper, the issue related to control of the plant with nonconstant parameters is addressed. In order to assure the unchanged response of the system, an adaptive state feedback speed controller for permanent magnet synchronous motor is proposed. The model-reference adaptive system is applied while the Widrow-Hoff rule is used as adjustment mechanism of controller’s coefficients. Necessary modifications related to construction of the cost function and formulas responsible for adjustment of state feedback speed controller’s coefficients are depicted. The impact of adaptation gain, which is the only parameter in proposed adjustment mechanism, on system behaviour is experimentally examined. The discussion about computational resources consumption of the proposed adaptation algorithm and implementation issues is included. The proposed approach is utilized in numerous experimental tests on modern SiC based drive with nonconstant moment of inertia. Comparison between adaptive and nonadaptive control schemes is also shown.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78893584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computationally efficient method for determining the most important electrical parameters of axial field permanent magnet machine","authors":"A. Smoleń, M. Gołębiowski","doi":"10.24425/bpas.2018.125943","DOIUrl":"https://doi.org/10.24425/bpas.2018.125943","url":null,"abstract":"Bull. Pol. Ac.: Tech. 66(6) 2018 Abstract. This paper describes a numerically efficient method for determining the electrical parameters of axial field permanent magnet machine (AFPM). The presented method aims to accurately determine the back EMF waveform and self-inductance coefficients, while maintaining possibly low computational complexity, which is crucial in case of incorporation of the method in numerical optimization procedure of AFPM construction. The described algorithm is based on 2D FEM with several simplifications. The obtained results have been compared with full 3D FEA conducted with Ansys/Maxwell software, and confirmed by measurements. The result shows that presented method ensures satisfactory accuracy as well as computational time performance.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81242216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residual life estimation of fabricated humidity sensors using different artificial intelligence techniques","authors":"C. Bhargava, Jaya Aggarwal, P. Sharma","doi":"10.24425/bpas.2019.127344","DOIUrl":"https://doi.org/10.24425/bpas.2019.127344","url":null,"abstract":"Background: a humidity sensor is used to sense and measure the relative humidity of air. A new composite system has been fabricated using environmental pollutants such as carbon black and low-cost zinc oxide, and it acts as a humidity sensor. Residual life of the sensor is calculated and an expert system is modelled. For properties and nature confirmation, characterization is performed, and a sensing material is fabricated. Methodology: characterization is performed on the fabricated material. Complex impedance spectroscopy (CIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) are all used to confirm the surface roughness, its composite nature as well as the morphology of the composite. The residual lifetime of the fabricated humidity sensor is calculated by means of accelerated life testing. An intelligent model is designed using artificial intelligence techniques, including the artificial neural network (ANN), fuzzy inference system (FIS) and adaptive neuro-fuzzy inference system (ANFIS). Results: maximum conductivity obtained is 6.4£10−3 S/cm when zinc oxide is doped with 80% of carbon black. Conclusion: the solid composite obtained possesses good humidity-sensing capability in the range of 30–95%. ANFIS exhibits the maximum prediction accuracy, with an error rate of just 1.1%.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91158638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy-based spectrum sensing with copulas for cognitive radios","authors":"F.Y. Ilgin","doi":"10.24425/bpasts.2020.134177","DOIUrl":"https://doi.org/10.24425/bpasts.2020.134177","url":null,"abstract":"In this study, an energy-based spectrum sensing method combined with copula theory is proposed for cognitive radio systems. In the proposed spectrum sensing model, cognitive radio users first make their own local spectrum decision with energy-based spectrum sensing. Then, they forward their decision to the fusion center. In the fusion center, this decision is compared with the threshold value determined by copula theory and global spectrum decision is made. The test statistic at the fusion center were obtained with the Neyman Pearson approach. Thus, the fusion rule was created for the fusion center and necessary simulation studies were performed. According to the results of the simulation studies, the proposed detection method showed better results than the traditional energy based detection method.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135544612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current harmonic controller in multiple reference frames for series active power filter integrated with 18-pulse diode rectifier","authors":"W. Śleszyński, A. Cichowski, P. Mysiak","doi":"10.24425/bpas.2018.125336","DOIUrl":"https://doi.org/10.24425/bpas.2018.125336","url":null,"abstract":"","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135544925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of random bio-hydrodynamic lubrication parameters for joints with phospholipid bilayers","authors":"Krzysztof Wierzcholski, Andrzej Miszczak","doi":"10.24425/bpasts.2021.135834","DOIUrl":"https://doi.org/10.24425/bpasts.2021.135834","url":null,"abstract":"This paper presents a new form of a mathematical estimation of stochastic bio-hydrodynamic lubrication parameters for real human joint surfaces with phospholipid bilayers. In this work, the authors present the analytical and stochastic considerations, which are based on the measurements of human joint surfaces. The gap is restricted between two cooperating biological surfaces. After numerous experimental measurements, it directly follows that the random symmetrical as well as unsymmetrical increments and decrements of the gap height in human joints influence the hydrodynamic pressure, load-carrying capacity, friction forces, and wear of the cooperating cartilage surfaces in human joints. The main focus of the paper was to demonstrate the influence of variations in the expected values and standard deviation of human joint gap height on the hydrodynamic lubrication parameters occurring in the human joint. It is very important to notice that the new form of apparent dynamic viscosity of synovial fluid formulated by the authors depends on ultra-thin gap height variations. Moreover, evident connection was observed between the apparent dynamic viscosity and the properties of cartilage surface coated by phospholipid cells. The above observations indicate an indirect impact of stochastic changes in the height of the gap and the indirect impact of random changes in the properties of the joint surface coated with the phospholipid layers, on the value of hydrodynamic pressure, load carrying capacity and friction forces. In this paper the authors present a synthetic, comprehensive estimation of stochastic bio-hydrodynamic lubrication parameters for the cooperating, rotational cartilage bio-surfaces with phospholipid bilayers occurring in human joints. The new results presented in this paper were obtained taking into account 3D variations in the dynamic viscosity of synovial fluid, particularly random variations crosswise the film thickness for non-Newtonian synovial fluid properties. According to the authors’ knowledge, the obtained results are widely applicable in spatiotemporal models in biology and health science.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135545571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On elastic contact problems of micro-periodic slant layered composite pressed by a rigid punch with a parabolic or rectangular shape","authors":"Piotr Sebestianiuk, Dariusz M. Perkowski, Roman Kulchytsky-Zhyhailo","doi":"10.24425/bpasts.2021.138091","DOIUrl":"https://doi.org/10.24425/bpasts.2021.138091","url":null,"abstract":". The paper presents an analysis of the influence of the shape of the rigid body pressed into the micro-periodic composite half-space on the examples of two punch shapes – parabolic and rectangular. The presented material is a layered body that consists of infinitely many thin alternately arranged homogenous layers. Layers of the presented composite are oblique to the boundary surface. Two cases of punch tip shape are examined – parabolic and rectangular. The presented problem has been formulated within the framework of a homogenized model with microlocal parameters and solved using the elastic potentials method and averaged boundary condition. Fourier integral transform method has been used to obtain the solution and the inverse integrals have been calculated numerically. Solutions in terms of contact pressure and maximum pressure characteristics were shown in the form of graphs.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135545573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trajectory tracking control of a mobile manipulator with an external force compensation","authors":"Mirosław Galicki","doi":"10.24425/bpasts.2021.137943","DOIUrl":"https://doi.org/10.24425/bpasts.2021.137943","url":null,"abstract":"This paper considers the problem of the accurate task space finite-time control susceptible to both undesirable disturbance forces exerted on the end-effector and unknown friction forces coming from joints directly driven by the actuators as well as unstructured forces resulting from the kinematic singularities appearing on the mechanism trajectory. We obtain a class of estimated extended transposed Jacobian controllers which seem to successfully counteract the external disturbance forces on the basis of a suitably defined task-space non-singular terminal sliding manifold (TSM) and the Lyapunov stability theory. Moreover, in order to overcome (or to minimise) the undesirable chattering effects, the proposed robust control law involves the second-order sliding technique. The numerical simulations (closely related to an experiment) ran for a mobile manipulator consisting of a non-holononic platform of (2,0) type and a holonomic manipulator of two revolute kinematic pairs show the performance of the proposed controllers and make a comparison with other well-known control schemes.","PeriodicalId":55299,"journal":{"name":"Bulletin of the Polish Academy of Sciences-Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135545587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}