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Gdańsk University of Technology

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Publications from the year 2023

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  • Określanie liczby sygnałów echa w zmodyfikowanej metodzie Prony’ego w zastosowaniu do echosondy interferometrycznej
    • Piotr Grall
    2023 Full text

    W rozprawie zaprezentowana została analiza możliwości poprawy dokładności określania głębokości w echosondzie interferometrycznej. Analiza dostępnych źródeł wykazała, że jednym ze sposobów na osiągnięcie poprawy dokładności jest zastosowanie zaawansowanych metod określania kierunku. Spośród odstępnych metod wybrano Zmodyfikowaną Metodę Prony’ego i zastosowano ją do przetwarzania sygnałów w echosondzie interferometrycznej. Aby poprawnie zastosować Zmodyfikowaną Metodę Prony’ego konieczne jest poprawne określanie liczby sygnałów echa. W rozprawie zaprezentowano opracowaną, nową metodę określania liczby sygnałów echa, która w zastosowaniu do Zmodyfikowanej Metody Prony’ego pozawala na poprawę dokładności określania głębokości w echosondzie interferometrycznej. Zaprezentowane zostały dwa warianty opracowanej metody, które umożliwiają jej zastosowanie w typowych, reprezentatywnych warunkach, w jakich pracuje echosonda interferometryczna w systemach hydrograficznych. Właściwości zaprezentowanej metody zostały zbadane dla symulowanych sygnałów ze stałego kierunku. W szczególności zbadano jak dekorelacja przestrzenna sygnału wpływa na skuteczność nowej metody w określaniu liczby sygnałów echa oraz dokładność określenia kierunku. Następnie sprawdzono właściwości zaproponowanej metody dla sygnałów symulowanych oraz dla sygnałów zarejestrowanych w warunkach rzeczywistych. W rezultacie przeprowadzonych badań wykazano poprawę dokładności określania kierunku/głębokości za pomocą Zmodyfikowanej Metody Prony’ego wraz z zaproponowaną metoda określania liczby sygnałów echa w stosunku do standardowego Metody Prony’ego bez modyfikacji.

  • On a 3D material modelling of smart nanocomposite structures
    • Mohammad Malikan
    • Shahriar Dastjerdi
    • Victor Eremeev
    • Hamid M. Sedighi
    2023 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    Smart composites (SCs) are utilized in electro-mechanical systems such as actuators and energy harvesters. Typically, thin-walled components such as beams, plates, and shells are employed as structural elements to achieve the mechanical behavior desired in these composites. SCs exhibit various advanced properties, ranging from lower order phenomena like piezoelectricity and piezomagneticity, to higher order effects including flexoelectricity and flexomagneticity. The recently discovered flexomagneticity in smart composites has been investigated under limited conditions. A review of the existing literature indicates a lack of evaluation in three-dimensional (3D) elasticity analysis of SCs when the flexomagnetic effect (FM) exists. To address this issue, the governing equations will incorporate the term ∂/∂z, where z represents the thickness coordinate. The variational technique will guide us in further developing these governing equations. By using hypotheses and theories such as a 3D beam model, von Kármán's strain nonlinearity, Hamilton's principle, and well-established direct and converse FM models, we will derive the constitutive equations for a thick composite beam. Conducting a 3D analysis implies that the strain and strain gradient tensors must be expressed in 3D forms. The inclusion of the term ∂/∂z necessitates the construction of a different model. It should be noted that current commercial finite element codes are not equipped to accurately and adequately handle micro- and nano-sized solids, thus making it impractical to model a flexomagnetic composite structure using these programs. Therefore, we will transform the derived characteristic linear three-dimensional bending equations into a 3D semi-analytical Polynomial domain to obtain numerical results. This study demonstrates the importance of conducting 3D mechanical analyses to explore the coupling effects of multiple physical phenomena in smart structures.

  • On analysis of nanocomposite conical structures
    • Shahriar Dastjerdi
    • Ömer Civalek
    • Mohammad Malikan
    • Bekir Akgöz
    2023 INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    This research examines the analysis of rotating truncated conical baskets reinforced by carbon nanotubes around the two independent axes. A time-dependent analysis is considered, and the nonlinear dynamic governing equations are extracted using the energy method. Carbon nanotubes (CNTs) reinforced the conical basket, and the structure's mechanical properties are determined based on the several distributions of carbon nanotubes. The novel design of a two-axis rotating conical basket is used as a centrifuge device and its resistance is investigated at different rotational velocities around the two independent axes. The partial differential governing equations are solved to obtain the structure's deformations. It can be seen that the structure undergoes much deformation against rotational velocities (significantly two-axis rotations). By reinforcing the conical basket with CNTs, its resistance increased, and a considerable part of the deformations resulting from the accelerated rotation will be neutralized. The results of novel presented formulation are validated, and the effectiveness of the dynamics formulation and solution method is proved. Also, the effects of various parameters on the research, such as the type of CNTs distribution and two-axis angular rotational velocities, are carefully examined. The results of this research can provide valuable information about the resistance of conical centrifuges reinforced with carbon nanotubes for other researchers. Also, it is noteworthy to mention that a novel approach has been presented for the dynamic deformation analysis of perforated centrifuges.

  • On bidirectional preestimates and their application to identification of fast time-varying systems
    • Maciej Niedźwiecki
    • Artur Gańcza
    • Lu Shen
    • Yuriy Zakharov
    2023 Full text

    When applied to the identification of time-varying systems, such as rapidly fading telecommunication channels, adaptive estimation algorithms built on the local basis function (LBF) principle yield excellent tracking performance but are computationally demanding. The subsequently proposed fast LBF (fLBF) algorithms, based on the preestimation principle, allow a substantial reduction in complexity without significant performance losses. We propose a novel preestimator, called bidirectional, which further improves the performance of the fLBF scheme.

  • On dynamic modeling of piezomagnetic/flexomagnetic microstructures based on Lord–Shulman thermoelastic model
    • Mohammad Malikan
    • Victor Eremeev
    2023 Full text ARCHIVE OF APPLIED MECHANICS

    We study a time-dependent thermoelastic coupling within free vibrations of piezomagnetic (PM) microbeams considering the flexomagnetic (FM) phenomenon. The flexomagneticity relates to a magnetic field with a gradient of strains. Here, we use the generalized thermoelasticity theory of Lord–Shulman to analyze the interaction between elastic deformation and thermal conductivity. The uniform magnetic field is permeated in line with the transverse axis. Using the strain gradient approach, the beam yields microstructural properties. The analytical solving process has been gotten via applying sine Fourier technique on displacements. Graphical illustrations are assigned to shape numerical examples concerning variations in essential physical quantities. It was observed that the flexomagnetic effect could be extraordinary if the thermal conductivity of the material is higher or the thermal relaxation time of the heat source is lesser. This theoretical study will provide the way of starting studies on magneto-thermoelastic small-scale piezo-flexomagnetic structures based on the heat conduction models.

  • On dynamics of origami-inspired rod
    • Igor Berinskii
    • Victor Eremeev
    2023 INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We discuss the dynamics of a relatively simple origami-inspired structure considering discrete and continuum models. The latter was derived as a certain limit of the discrete model. Here we analyze small in-plane deformations and related equations of infinitesimal motions. For both models, dispersion relations were derived and compared. The comparison of the dispersion relations showed that the continuum model can capture the behavior of origami structures, which can be helpful in the materials properties determination and nondestructive evaluation.

  • On implementation of fibrous connective tissues’ damage in Abaqus software
    • Agnieszka Sabik
    • Wojciech Witkowski
    2023 JOURNAL OF BIOMECHANICS

    Connective fibrous tissues, such as tendons and ligaments, in humans and animals exhibit hyperelastic behaviour. The constitution of the material of these tissues is anisotropic due to the presence of the collagen fibres, where one family of fibres is the typical case. Traumatic events and/or aging may sometimes lead to the damage of the tissue. The study of motion of affected joints or limbs is usually not permitted in vivo. This is where finite element method (FEM) becomes useful as a premise for general analysis, surgical planning or designing of implants and medical treatment. One of the most often used FEM commercial programs is the field of the biomechanics is Abaqus. The present study discusses the potential of user subroutine UANISOHYPER_INV in this code to analyse response of transversely isotropic tissue with damage in quasi-static range. This subroutine requires providing the material energy function and its derivatives only. The stress tensor and constitutive matrix are computed by the software automatically. To the best of the Authors’ knowledge this procedure provides the easiest way to simulate the anisotropic hyperelastic material behaviour in Abaqus. In this study its usage is extended onto the damage response simulation. The verification of the approach and its validation against experimental data indicates its efficiency.

  • On Nature-Inspired Design Optimization of Antenna Structures Using Variable-Resolution EM Models
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2023 Full text Scientific Reports

    Numerical optimization has been ubiquitous in antenna design for over a decade or so. It is indispensable in handling of multiple geometry/material parameters, performance goals, and constraints. It is also challenging as it incurs significant CPU expenses, especially when the underlying computational model involves full-wave electromagnetic (EM) analysis. In most practical cases, the latter is imperative to ensure evaluation reliability. The numerical challenges are even more pronounced when global search is required, which is most often carried out using nature-inspired algorithms. Population-based procedures are known for their ability to escape from local optima, yet their computational efficiency is poor, which makes them impractical when applied directly to EM models. A common workaround is the utilization of surrogate modeling techniques, typically in the form of iterative prediction-correction schemes, where the accumulated EM simulation data is used to identify the promising regions of the parameter space and to refine the surrogate model predictive power at the same time. Notwithstanding, implementation of surrogate-assisted procedures is often intricate, whereas their efficacy may be hampered by the dimensionality issues and considerable nonlinearity of antenna characteristics. This work investigates the benefits of incorporating variable-resolution EM simulation models into nature-inspired algorithms for optimization of antenna structures, where the model resolution pertains to the level of discretization density of an antenna structure in the full-wave simulation model. The considered framework utilizes EM simulation models which share the same physical background and are selected from a continuous spectrum of allowable resolutions. The early stages of the search process are carried out with the use of the lowest fidelity model, which is subsequently automatically increased to finally reach the high-fidelity antenna representation (i.e., considered as sufficiently accurate for design purposes). Numerical validation is executed using several antenna structures of distinct types of characteristics, and a particle swarm optimizer as the optimization engine. The results demonstrate that appropriate resolution adjustment profiles permit considerable computational savings (reaching up to eighty percent in comparison to high-fidelity-based optimization) without noticeable degradation of the search process reliability.

  • On Rapid Design Optimization and Calibration of Microwave Sensors Based on Equivalent Complementary Resonators for High Sensitivity and Low Fabrication Tolerance
    • Tanveer Haq Ul
    • Sławomir Kozieł
    2023 Full text SENSORS

    This paper presents the design, optimization, and calibration of multivariable resonators for mi-crowave dielectric sensors. An optimization technique for circular complementary split ring reso-nator (CC-SRR) and square complementary split ring resonator (SC-SRR) is presented to achieve the required transmission response in a precise manner. The optimized resonators are manufac-tured using a standard photolithographic technique and measured for fabrication tolerance. The fabricated sensor is presented for high-resolution characterization of dielectric substrates and oil samples. A three-dimensional dielectric container is attached to the sensor, which acts as a pool for the sample under test (SUT). In the presented technique, the dielectric substrates and oil sam-ples can interact directly with the electromagnetic (EM) field emitted from the resonator. For the sake of sensor calibration, a relation between the relative permittivity of the dielectric samples and the resonant frequency of the sensor is established in the form of the inverse regression model. Comparisons with state-of-the-art sensors indicate the superiority of the presented design in terms of oil characterization reliability. The significant technical contributions of this work include the employment of rigorous optimization of geometry parameters of the sensor leading to its superior performance, the development and application of the inverse-model-based calibration procedure.

  • On the exact equilibrium conditions of irregular shells reinforced by beams along the junctions
    • Violetta Konopińska-Zmysłowska
    2023 Full text CONTINUUM MECHANICS AND THERMODYNAMICS

    The exact, resultant equilibrium conditions for irregular shells reinforced by beams along the junctions are formulated. The equilibrium conditions are derived by performing direct integration of the global equilibrium conditions of continuum mechanics. New, exact resultant static continuity conditions along the singular curve modelling reinforced junction are presented. The results do not depend on shell thickness, internal through-the-thickness shell structure, or material properties of shell and beam elements. In this theoretical approach, the beam’s kinematics is represented by the elastic Cosserat curve. Kinematically, the six-parameter model of shell structures coincides with the Cosserat curve model of the beam. The presented method can be easily applied to cases of connection of three or four shell elements with the reinforcement along the junction.

  • On the Importance of Resilience Engineering for Networked Systems in a Changing World
    • David Hutchison
    • Dimitrios Pezaros
    • Jacek Rak
    • Paul Smith
    2023 Full text IEEE COMMUNICATIONS MAGAZINE

    Resilience is featured increasingly often in the media, usually applied to society when faced, for example, with disasters such as flooding and the enormous challenges that the Covid-19 pandemic posed. There are now many resilience-related discussion groups worldwide, and some standards initiatives devoted in particular to city resilience. However, there is relatively little explicit interest in resilience engineering for communication networks and systems, including the Internet. This is perhaps surprising, given the reliance that society now places on networks and networked systems. This article reflects on key issues and developments that may change this perspective; we summarize recent and current research in resilient systems and, consequently, propose a multidisciplinary research agenda in resilience engineering for networked systems.

  • On the Possibility of Increasing Ship Energy Efficiency Through Improved Propulsion Control System
    • Mohammad Ghaemi
    2023

    This paper summarizes the analyses conducted to assess the impact of the ship's propulsion control system on energy efficiency in calm, manoeuvre, and sea wave conditions, where the goal of the investigation is to develop new strategies for controlling the ship's motion while considering the interactions between the hull, engine, and propeller.

  • On the recognition of the game type based on physiological signals and eye tracking
    • Mariusz Szwoch
    • Łukasz Czekaj
    • Łukasz Radzinski
    • Robert Kitłowski
    • Włodzisław Duch
    • Jakub Domaszewicz
    • Mateusz Kolimaga
    2023

    Automated interpretation of signals yields many impressive applications from the area of affective computing and human activity recognition (HAR). In this paper we ask the question about possibility of cognitive activity recognition on the base of particular set of signals. We use recognition of the game played by the participant as a playground for exploration of the problem. We build classifier of three different games (Space Invaders, Tetris, Tower Defence) and inter-game pause. We validate classifier in the player-independent and playerdependent scenario. We discuss the improvement in the player-dependent scenario in the context of biometric person recognition. On the base of the results obtained in game classification, we consider potential applications in smart surveillance and quantified self.

  • On the use of leading safety indicators in maritime and their feasibility for Maritime Autonomous Surface Ships
    • Krzysztof Wróbel
    • Mateusz Gil
    • Przemysław Krata
    • Karol Olszewski
    • Jakub Montewka
    2023 Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability

    Although the safety of prospective Maritime Autonomous Surface Ships will largely depend on their ability to detect potential hazards and react to them, the contemporary scientific literature lacks the analysis of how to achieve this. This could be achieved through an application of leading safety indicators. The aim of the performed study was to identify the research directions of leading safety indicators in three safety-critical operational aspects of Maritime Autonomous Surface Ships: collision avoidance, intact stability, and communication. To achieve this, literature review is performed, taking into account scientific documents including journal and conference papers. The results indicate that the need for establishing operational leading safety indicators is recognized by numerous scholars, who sometimes make suggestions of what the set of indicators shall consist of. Some leading safety indicators for autonomous vessels are readily identifiable in the scientific literature and used in current practice. However, the research effort is lacking a holistic approach to the issue.

  • On time-dependent nonlinear dynamic response of micro-elastic solids
    • Mohammad Malikan
    • Victor Eremeev
    2023 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    A new approach to the mechanical response of micro-mechanic problems is presented using the modified couple stress theory. This model captured micro-turns due to micro-particles' rotations which could be essential for microstructural materials and/or at small scales. In a micro media based on the small rotations, sub-particles can also turn except the whole domain rotation. However, this framework is competent for a static medium. In terms of dynamic investigations of micro materials, it is required to involve micro-rotations' mass inertias. This fact persuades us to pay particular attention to the micro mechanics' samples and directed us to re-derive the modified couple stress model to propose and represent a new micro-mechanic approach which is well-deserved, especially for dynamic studies of microstructures. In carrying out this job, the classical beam has provided the basic form of formulation procedure. The continuum medium has been limited to a square flat non-porous beam deducing a homogeneous isotropic micromaterial. As long as the time-dependent results are concerned due to studying micro-mass inertia in time history, there would be two solution steps. The Galerkin decomposition technique is imposed in accord with an analytical postulate to issue the algebraic problem distributing time-dependent equations. The latter, the Homotopy perturbation method delivers time-dependent outcomes. The solution methods have been validated by building numerical models in Abaqus software. On the new achievements of this study, one can declare that both static and dynamic length scale parameters are very effective in order to study vibrations of microstructures. If the values of these characteristic lengths are considerable, the nonlinear frequency analysis will be essential.Furthermore, the stiffness of the structure will be higher if the values of both length scale parameters increase.

  • On Unsupervised Artificial-Intelligence-Assisted Design of Antennas for High-Performance Planar Devices
    • Sławomir Kozieł
    • Weiping Dou
    • Peter Renner
    • Andrew Cohen
    • Yuandong Tian
    • Jiang Zhu
    • Anna Pietrenko-Dąbrowska
    2023 Full text Electronics

    Design of modern antenna structures is a challenging endeavor. It is laborious, and heavily reliant on engineering insight and experience, especially at the initial stages oriented towards the devel-opment of a suitable antenna architecture. Due to its interactive nature and hands-on procedures (mainly parametric studies) for validating suitability of particular geometric setups, typical antenna development requires many weeks and significant involvement of a human expert. The same reasons only allow the designer to try out a very limited number of options in terms of antenna geometry arrangements. Automated topology development and dimension sizing is therefore of high interest, especially from industry perspective where time-to-market and expert-related ex-penses are of paramount importance. This paper discusses a novel approach to unsupervised specification-driven design of planar antennas. The presented methodology capitalizes on a flexi-ble and scalable antenna parameterization, which enables realization of complex geometries while maintaining reasonably small parameter space dimensionality. A customized nature-inspired al-gorithm is employed to carry out space exploration and identification of a quasi-optimum antenna topology in a global sense. A fast gradient-based procedure is then incorporated to fine tune an-tenna dimensions. The design framework works entirely in a black-box fashion with the only in-put being design specifications, and optional constraints, e.g., concerning the structure size. Nu-merous illustration case studies demonstrate the capability of the presented technique to generate unconventional antenna topologies of satisfactory performance using reasonable computational budgets, and with no human expert interaction necessary whatsoever.

  • On well-posedness of the first boundary-value problem within linear isotropic Toupin–Mindlin strain gradient elasticity and constraints for elastic moduli
    • Victor Eremeev
    2023 Full text ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik

    Within the linear Toupin–Mindlin strain gradient elasticity we discuss the well-posedness of the first boundary-value problem, that is, a boundary-value problem with Dirichlet-type boundary conditions on the whole boundary. For an isotropic material we formulate the necessary and sufficient conditions which guarantee existence and uniqueness of a weak solution. These conditions include strong ellipticity written in terms of higher-order elastic moduli and two inequalities for the Lamé moduli. The conditions are less restrictive than those followed from the positive definiteness of the deformation energy.

  • One More Step Towards a Circular Economy for Thermal Insulation Materials—Development of Composites Highly Filled with Waste Polyurethane (PU) Foam for Potential Use in the Building Industry
    • Łukasz Kowalczyk
    • Jerzy Korol
    • Błażej Chmielnicki
    • Aleksandra Laska
    • Daniel Chuchała
    • Aleksander Hejna
    2023 Full text Materials

    The rapid development of the building sector has created increased demand for novel materials and technologies, while on the other hand resulting in the generation of a severe amount of waste materials. Among these are polyurethane (PU) foams, which are commonly applied as thermal insulation materials. Their management is a serious industrial problem, due to, for example, their complex chemical composition. Although some chemical and thermochemical methods of PU foam recycling are known, their broader use is limited due to requirements related to the complexity and safety of their installation, thus implicating high costs. Therefore, material recycling poses a promising alternative. The incorporation of waste PU foams as fillers for polymer composites could make it possible to take advantage of their structure and performance. Herein, polypropylene-based composites that were highly filled with waste PU foam and modified using foaming agents were prepared and analyzed. Depending on the foam loading and the foaming agent applied, the apparent density of material was reduced by as much as 68%. The efficient development of a porous structure, confirmed by scanning electron microscopy and high-resolution computed micro-tomography, enabled a 64% decrease in the thermal conductivity coefficient. The foaming of the structure affected the mechanical performance of composites, resulting in a deterioration of their tensile and compressive performance. Therefore, developing samples of the analyzed composites with the desired performance would require identifying the proper balance between mechanical strength and economic, as well as ecological (share of waste material in composite, apparent density of material), considerations.

  • Ongoing Progress on Pervaporation Membranes for Ethanol Separation
    • Muhammad Imad
    • Roberto Castro Munoz
    2023 Full text Membranes

    Ethanol, a versatile chemical extensively employed in several fields, including fuel production, food and beverage, pharmaceutical and healthcare industries, and chemical manufacturing, continues to witness expanding applications. Consequently, there is an ongoing need for cost-effective and environmentally friendly purification technologies for this organic compound in both diluted (ethanol-water–) and concentrated solutions (water-ethanol–). Pervaporation (PV), as a membrane technology, has emerged as a promising solution offering significant reductions in energy and resource consumption during the production of high-purity components. This review aims to provide a panorama of the recent advancements in materials adapted into PV membranes, encompassing polymeric membranes (and possible blending), inorganic membranes, mixed-matrix membranes, and emerging two-dimensional-material membranes. Among these membrane materials, we discuss the ones providing the most relevant performance in separating ethanol from the liquid systems of water–ethanol and ethanol–water, among others. Furthermore, this review identifies the challenges and future opportunities in material design and fabrication techniques, and the establishment of structure–performance relationships. These endeavors aim to propel the development of next-generation pervaporation membranes with an enhanced separation efficiency.

  • Ontological Modeling for Contextual Data Describing Signals Obtained from Electrodermal Activity for Emotion Recognition and Analysis
    • Teresa Zawadzka
    • Tomasz Wierciński
    • Wojciech Waloszek
    • Michał Wróbel
    2023 Full text IEEE Access

    Most of the research in the field of emotion recognition is based on datasets that contain data obtained during affective computing experiments. However, each dataset is described by different metadata, stored in various structures and formats. This research can be counted among those whose aim is to provide a structural and semantic pattern for affective computing datasets, which is an important step to solve the problem of data reuse and integration in this domain. In our previous work, the ROAD ontology was introduced. This ontology was designed as a skeleton for expressing contextual data describing time series obtained in various ways from various signals and was focused on common contextual data, independent of specific signals. The aim of the presented research is to provide a carefully curated vocabulary for describing signals obtained from electrodermal activity, a very important subdomain of emotion analysis. We decided to present it as an extension to the ROAD ontology in order to offer means of sharing metadata for datasets in a unified and precise way. To meet this aim, the research methodology was defined, mostly focusing on requirements specification and integration with other existing ontologies. Application of this methodology resulted firstly in sharing the requirements to allow a broader discussion and secondly development of the EDA extension of the ROAD ontology, validated against the MAHNOB-HCI dataset. Both these results are very important with respect to the vast context of the work, i.e. providing an extendable framework for describing affective computing experiments. Introducing the methodology also opens the way for providing new extensions systematically just by executing the steps defined in the methodology.