2022 - Publications Repository - Gdańsk University of Technology

Show publications from the year

Publications from the year 2022

Show all

Evaluation of pounding effects between reinforced concrete frames subjected to far-field earthquakes in terms of damage index
- S. H. Hosseini
- H. Naderpour
- R. Vahdani
- Robert Jankowski
2022 Full text Bulletin of Earthquake Engineering
In this paper, three different damage indexes were used to detect nonlinear damages in two adjacent Reinforced Concrete (RC) structures considering pounding effects. 2-, 4- and 8-story benchmark RC Moment Resisting Frames (MRFs) were selected for this purpose with 60%, 75%, and 100% of minimum separation distance and also without any in-between separation gap. These structures were analyzed using the incremental dynamic analysis method under 44 far-field ground motion records. Comparison of the results between the MRFs with and without considering pounding effects show that collisions lead to a decrease in the values of coefficient of determination and the nonlinear damage occurs in lower seismic intensity. As a result, using the damage indexes, nonlinear damages can be detected during a specific seismic intensity. Moreover, considering a minimum separation distance leads to an increase in the coefficient of determination between the damage index and the maximum story drift ratio. Furthermore, due to pounding, shorter MRFs are damaged more significantly than the taller structures.
Evaluation of Sicilian landraces of broccoli (B. oleracea var. italica Plenck) for quality traits
- M.c. Di Bella
- S. Treccarichi
- D. Arena
- R. Nicotra
- A. Mazzaglia
- M.g. Melilli
- Agnieszka Bartoszek-Pączkowska
- Barbara Kusznierewicz
- Karol Parchem
- F. Branca
2022
Brassica oleracea L. var. italica Plenck is one of the most popular vegetables which belong to Brassicaceae family. It is getting attention as an important source of bioactive compounds such as glucosinolates, and many other phytochemicals. In the frame of the H2020 BRESOV project, we evaluated three landraces (‘Broccolo nero', ‘Ramoso calabrese' and ‘Sparaceddu') and two commercial F1 hybrid cultivars (‘Marathon' and ‘Naxos'). The seedlings were transplanted in Mojo-Alcantara (Sicily) in November 2020 (4 plant m-2) to monitor plant phenological stages and biometric, sensorial, and biochemical traits of the produce. Plants were characterized through bio-morphometric parameters using the following descriptors: stem and basal diameter, grain size, colour, soluble solid content; sensorial analysis by panel test was performed using fresh inflorescence appearance and leaves portions. Biochemical analysis of glucosinolates (GLSs) amount and their profile were carried out using freeze-dried samples of the evaluated accession. The results showed significant differences, among genotypes, in plant habitus, sprouting/branching and flowering time. The most performing genotype in term of inflorescence weight was ‘Naxos' (415.6 g), followed by ‘Marathon' (112.7 g). The Sicilian landraces ‘Broccolo nero' and ‘Sparaceddu' showed lower curd diameter (35.6 and 21.5 mm, respectively) than commercial F1 hybrids ‘Marathon' and ‘Naxos' (84.3 and 151.3 mm, respectively). Concerning soluble solid content, it was high in ‘Sparaceddu' (8.53 °Brix), ‘Naxos' F1(8.30 °Brix) and ‘Broccolo nero' (8.14 °Brix), while it was low in ‘Marathon' F1 (6.12 °Brix). The ANOVA results of the sensory data showed significant differences (p≤0.05) in the attributes colour intensity and overall. Among the Sicilian landraces, the accession ‘Sparaceddu' had the highest content of total GLSs (20.21 µmol dw1), and its profile was very articulated in comparison to the hybrid F1 ‘Naxos'.
Evaluation of the Cathodic Electrodeposition Effectiveness of the Hydroxyapatite Layer Used in Surface Modification of Ti6Al4V-Based Biomaterials
- Michalina Ehlert
- Aleksandra Radtke
- Michał Bartmański
- Piotr Piszczek
2022 Full text Materials
The important issue associated with the design and the fabrication of the titanium and titanium alloy implants is the increase of their biointegration with bone tissue. In the presented paper, the research results concerning the conditions used in the cathodic deposition of hydroxyapatite on the surface Ti6Al4V substrates primarily modified by the production of TiO2 nanoporous coatings, TiO2 nanofibers, and titanate coatings, are discussed. Despite excellent biocompatibility with natural bone tissue of materials based on hydroxyapatite (HA), their poor adhesion to the substrate caused the limited use in the implants’ construction. In our works, we have focused on the comparison of the structure, physicochemical, and mechanical properties of coating systems produced at different conditions. For this purpose, scanning electron microscopy images, chemical composition, X-ray diffraction patterns, infrared spectroscopy, wettability, and mechanical properties are analyzed. Our investigations proved that the intermediate titanium oxide coatings presence significantly increases the adhesion between the hydroxyapatite layer and the Ti6Al4V substrate, thus solving the temporary delamination problems of the HA layer.
Evaluation of the Impact of Different Types of Uncoupling on the Processing Capacity of Hump Yards
- Miroslava Mikusova
- Matljuba Khajimuhamedova
- Joanna Żukowska
- Tomasz Mackun
2022 Full text Periodica Polytechnica Transportation Engineering
The paper considers the issue of evaluating the impact of different types of uncoupling to increase the processing capacity of hump yards to ensure high technical-economic indicators in the conditions of limited capital funds. Moreover it describes the mathematical formulation of the sorting slide. For the mathematical formulation, the sorting slide is taken as a surface that is uniquely projected onto a horizontal plane. Based on the results of calculations, more accurate data on the speeds of movement along the downhill part of the slide are determined. This data is compared with experimental results.
Evidence of the impact of sport policies on physical activity and sport participation: a systematic mixed studies review
- Kevin Volf
- Liam Kelly
- Enrique García Bengoechea
- Bláthín Casey
- Peter Gelius
- Sven Messing
- Sarah Forberger
- Jeroen Lakerveld
- Nicolette R. Den Braver
- Joanna Żukowska
- Catherine Woods
2022 Full text International Journal of Sport Policy and Politics
Participation in sport contributes to increased physical activity (PA) levels. Increasing PA is a public health concern due to its recognised impact on health outcomes. International policy actors such as the Council of Europe, the World Health Organisation (WHO) and the International Society for Physical Activity and Health (ISPAH) have recommended that ‘sport for all’ is promoted both for public health and as a basic right. This review aims to evaluate sport related policies aimed at maximising the opportunity to participate in PA and sporting activity. Six electronic databases were systematically searched for quantitative, qualitative and review studies investigating how public sport policy affects PA outcomes. The scientific literature was screened according to predetermined eligibility criteria. Following study selection and data extraction, the quality was assessed using modified versions of existing quality assessment tools. Results were synthesised and the context in which policy actions occurred analysed using the Context and Implementation of Complex Interventions (CICI) framework. Database searches identified 3705 unique articles. A total of 93 full-text articles were assessed, with 22 meeting our inclusion criteria. Seven unique ‘policy actions’ were identified and were categorised into the ‘policy areas’ Facilities, Financial, Collaboration and Exhortation. Policy actions to promote PA and sport participation have demonstrated qualified success but there is limited evidence of success in engaging hard to reach groups. Therefore, policymakers utilising sport to increase PA should treat it as a complementary intervention alongside other policy actions based on a systems perspective.
Evolutionary Algorithm for Selecting Dynamic Signatures Partitioning Approach
- Marcin Zalasiński
- Łukasz Laskowski
- Tacjana Niksa-Rynkiewicz
- Krzysztof Cpałka
- Aleksander Byrski
- Krzysztof Przybyszewski
- Paweł Trippner
- Shi Dong
2022 Full text Journal of Artificial Intelligence and Soft Computing Research
In the verification of identity, the aim is to increase effectiveness and reduce involvement of verified users. A good compromise between these issues is ensured by dynamic signature verification. The dynamic signature is represented by signals describing the position of the stylus in time. They can be used to determine the velocity or acceleration signal. Values of these signals can be analyzed, interpreted, selected, and compared. In this paper, we propose an approach that: (a) uses an evolutionary algorithm to create signature partitions in the time and velocity domains; (b) selects the most characteristic partitions in terms of matching with reference signatures; and (c) works individually for each user, eliminating the need of using skilled forgeries. The proposed approach was tested using Biosecure DS2 database which is a part of the DeepSignDB, a database with genuine dynamic signatures. Our simulations confirmed the correctness of the adopted assumptions.
Examination of advanced isotropic constitutive laws under complex stress states in plain and reinforced concrete specimens
- Jerzy Bobiński
- Patryk Chodkowski
- Jakub Schönnagel
2022
The performance of advanced isotropic constitutive laws under complex stress states in plain and reinforced concrete specimens is investigated. Three different formulations are chosen: original Mazars model, Mazars mi model and model proposed by Pereira and coworkers. The degradation of the material in all formulations is described via a single variable, but a strain/stress state is taken into account via quite sophisticated relationships. In order to better reproduce experimentally observed stress-strain curves in uniaxial tension and compression, some modifications and extensions are proposed. An integral non-local approach is used to ensure FE mesh insensitive results. Two benchmarks are simulated. Nooru-Mohamed test is chosen to analyse numerically the growth of cracks in plain concrete under mixed-mode stress conditions. A geometrically scaled set of longitudinally reinforced beams under four-point bending load serves to assess the ability of reproducing different failure mechanisms. All results obtained from calculations are compared with experimental outcomes.
Examination of epigenetic inhibitor zebularine in treatment of skin wounds in healthy and diabetic mice
- Piotr Sass
- Paweł Sosnowski
- Jolanta Kamińska
- Milena Deptuła
- Aneta Skoniecka
- Jacek Zieliński
- Sylwia Rodziewicz‐Motowidło
- Michał Pikuła
- Paweł Sachadyn
2022 Full text Journal of Tissue Engineering and Regenerative Medicine
DNA methyltransferase inhibitor zebularine was proven to induce regeneration in the ear pinna in mice. We utilized a dorsal skin wound model to further evaluate this epigenetic inhibitor in wound healing. Full-thickness excisional wounds were made on the dorsum of 2 and 10-month-old healthy BALB/c and 3 and 8-month-old diabetic (db/db) mice, followed by topical or intraperitoneal zebularine delivery. Depending on the strain, age, dose, and delivery, the zebularine treatments either had no effect or accelerated or delayed wound closure. In principle, zebularine applied topically moderately promoted wound closure in the healthy but markedly delayed in the diabetic mice, which was in line with decreased viability of cultured keratinocytes from diabetic patients exposed to zebularine. The histological analysis revealed an improvement in the architecture of restored skin in zebularine-treated mice, manifested as a distinct layered pattern resembling panniculus carnosus. The finding corresponds with the zebularine-mediated activation of the Wnt5a gene, an essential regulator of Wnt signaling, the pathway involved in hair follicle development, the process which in turn is connected with regenerative skin healing. Although zebularine did not remarkably accelerate wound healing, zebularine and other epigenetic inhibitors deserve further testing as potential drugs to improve the quality of restored skin.
Examining Impact of Speed Recommendation Algorithm Operating in Autonomous Road Signs on Minimum Distance between Vehicles
- Andrzej Sroczyński
- Adam Kurowski
- Szymon Zaporowski
- Andrzej Czyżewski
2022 Full text Remote Sensing
An approach to a new kind of recommendation system design that suggests safe speed on the road is presented. Real data obtained on roads were used for the simulations. As part of a project related to autonomous road sign development, a number of measurements were carried out on both local roads and expressways. A speed recommendation model was created based on gathered traffic data employing the traffic simulator. Depending on the traffic volume and atmospheric conditions prevailing on the road, as well as the surface conditions, the proposed system recommends the safe speed for passing vehicles by influencing the distance from the preceding vehicle to prevent collisions. The observed effect of the system application was an increase in the minimal distance between vehicles in most simulations.
Expedited Gradient-Based Design Closure of Antennas Using Variable-Resolution Simulations and Sparse Sensitivity Updates
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2022 Full text IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
Numerical optimization has been playing an increasingly important role in the design of contemporary antenna systems. Due to the shortage of design-ready theoretical models, optimization is mainly based on electromagnetic (EM) analysis, which tends to be costly. Numerous techniques have evolved to abate this cost, including surrogate-assisted frameworks for global optimization, or sparse sensitivity updates for speeding up local search. In the latter, CPU-heavy updates of the system response sensitivity through finite differentiation are suppressed based on, e.g., the magnitude of design variability during the optimization run. Another approach is to incorporate variable-resolution simulations. Recently, a technique exploiting a continuous spectrum of admissible model fidelity levels has been reported, thereby allowing for a considerable reduction of the computational expenditures. Seeking further savings, this work introduces an accelerated gradient-based algorithm with sparse sensitivity updates and variable-resolution EM simulations. Our technique is validated using four broadband antennas, and demonstrated to offer substantial (around eighty percent) savings over the benchmark while maintaining acceptable design quality.
Expedited Optimization of Passive Microwave Devices Using Gradient Search and Principal Directions
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
- Leifur Leifsson
2022
Over the recent years, utilization of numerical optimization techniques has become ubiquitous in the design of high-frequency systems, including microwave passive components. The primary reason is that the circuits become increasingly complex to meet ever growing performance demands concerning their electrical performance, additional functionalities, as well as miniaturization. Nonetheless, as reliable evaluation of microwave device characteristics requires full-wave electromagnetic (EM) analysis, optimization procedures tend to be computationally expensive, to the extent of being prohibitive when using conventional algorithms. Accelerating EM-driven optimization is therefore a matter of practical necessity. This paper proposes a novel approach to reduced-cost gradient-based parameter tuning of passive microwave circuits with numerical derivatives. Our technique is based on restricting the finite-differentiation (FD)-based sensitivity updates to a small set of principal directions, identified as having the most significant effect on the circuit responses over the frequency bands of interest. The principal directions are found in the form of an orthonormal basis, using an auxiliary optimization process repeated before each iteration of the optimization algorithm. Extensive verification experiments conducted using a com-pact branch-line coupler and a dual-band power divider demonstrate up to fifty percent speedup obtained over the reference algorithm (using full FD sensitivity updates), as well as a considerable improvement over several accelerated algorithms. The computational savings are obtained with negligible degradation of the design quality.
Expedited Variable-Resolution Surrogate Modeling of Miniaturized Microwave Passives in Confined Domains
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2022 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Design of miniaturized microwave components is largely based on computational models, primarily, full-wave electromagnetic (EM) simulations. EM analysis is capable of giving an accurate account for cross-coupling effects, substrate and radiation losses, or interactions with environmental components (e.g., connectors). Unfortunately, direct execution of EM-based design tasks such as parametric optimization or uncertainty quantification, may turn prohibitively expensive in computational terms. A workaround has been offered by surrogate-assisted procedures that capitalize on replacing expensive EM simulations by fast metamodels, notably data-driven ones. However, construction of general-purpose metamodels is impeded by the curse of dimensionality as well as a limited capability of approximation techniques to represent highly nonlinear responses of microwave devices. This paper proposes a novel technique that integrates the performance-driven modeling paradigm as well as variable-resolution EM simulations. The former focuses the construction of the surrogate in the parameter space subset encompassing high-quality designs, which effectively addresses the dimensionality issues. The latter—realized through co-kriging—contributes to further computational savings by executing the majority of circuit evaluations at the level of coarse-discretization EM analysis. Verification experiments conducted for three microstrip components demonstrate superiority of the proposed approach over existing performance-driven techniques, let alone conventional modeling procedures, both with respect to accuracy and computational cost of the surrogate construction.
Expedited Yield-Driven Design of High-Frequency Structures by Kriging Surrogates in Confined Domains
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2022
Uncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of high-frequency structures systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the characteristics of antennas or microwave devices. For example, in the case of narrow- or multi-band antennas, this usually leads to frequency shifts of the operating bands. Quantifying these effects is imperative to adequately assess the design quality, either in terms of the statistical moments of the performance parameters or the yield. Reducing the system sensitivity to parameter deviations is even more essential when increasing the probability of the system satisfying the prescribed requirements is of concern. The prerequisite of such procedures is statistical analysis, normally carried out at the level of full-wave electromagnetic (EM) analysis. Although necessary to ensure reliability, it entails considerable computational expenses, often prohibitive. Following the recently fostered concept of constrained modeling, this chapter discusses a simple technique for rapid surrogate-assisted yield optimization of high-frequency structures. The keystone of the approach is an appropriate definition of the optimization domain. This is realized by considering a few pre-optimized designs that represent the directions featuring maximum variability of the circuit responses (particularly the parts thereof that affect the yield value in the most significant way) with respect to its geometry parameters. Due to a small volume of such a domain, an accurate replacement model can be established therein using a small number of training samples, and employed to improve the yield. The implementation details are tailored to a particular type of device. Verification results obtained for several antenna structures and a miniaturized rat-race coupler indicate that the optimization process can be accomplished at low cost of a few dozen of EM simulations. The result reliability is validated through comparisons with EM-based Monte Carlo simulations.
Experience-based Intelligence Augmentation with Decisional DNA: Upcoming direction
- Edward Szczerbicki
- Cesar Sanin
2022 Full text
Intelligence amplification systems and technologies have gained significant interest from academia and industry during the past few decades. One of the main reasons behind this trend is the fact that most experts agree that truly intelligent artificial system is yet to be developed. The question increasing often asked is this: Is full replication of human intelligence desirable key aim in intelligence related technology and research? In this context, the concept of Augmented Intelligence, also known as Cognitive Augmentation or Intelligence Amplification (IA) comes into play. One of the main reasons behind this interest in this concept is the potential of such technologies to revolutionize human life as they intend to work under complex decision-making environments, adapting to a comprehensive range of unforeseen changes, and exhibiting prospective behavior. The combination of these properties aims to enhance human capabilities and create more intelligent and efficient human-centered environments. In this paper we discuss how Decisional DNA (DDNA), a multi-domain knowledge structure that has the Set of Experience Knowledge Structure (SOEKS) at its core can be utilized as an experience-based intelligence augmentation in a number of different domains.
Experimental and numerical identification of corrosion degradation of ageing structural components
- Beata Zima
- Krzysztof Wołoszyk
- Yordan Garbatov
2022 Full text OCEAN ENGINEERING
The study presents experimental and numerical identification of corrosion degradation of thin-walled structural components employing guided wave propagation. The steel structural components are subjected to through-thickness varying corrosion degradation levels. The developed approach using the non-destructive guided wave-propagation quantifies the equivalent average corrosion degradation level by exploring a limited number of transducers. A group velocity dispersion curve reconstruction has been used to determine the corrosion-induced plate thickness reduction. Two case studies are used to examine experimentally the newly developed approach. In the first one, the dispersion curve and the assessment of the corrosion thickness reduction have been made using wave signals of various excitation frequencies. In the second one, the analysis was conducted only for two wave propagation signals and one excitation frequency which allowed for reconstructing the dispersion curve in a limited frequency range. A good agreement between the natural and estimated corrosion degradation levels was observed in both case studies. The present study develops a signal processing methodology, which can be used in the SHM systems. Several aspects still need to be further investigated before the developed approach can be applied to the complex ship hull structures' large size and complex geometry.
Experimental and numerical investigations on RC beams with stirrups scaled along height or length.
- Ireneusz Marzec
- Andrzej Tejchman-Konarzewski
2022 Full text ENGINEERING STRUCTURES
Belki żelbetowe (RC) ze zbrojeniem poprzecznym (strzemiona) poddane czteropunktowemu zginaniu zostały zbadane eksperymentalnie i numerycznie. Belki były skalowane wzdłuż wysokości lub długości. Były przezbrojone, aby uniknąć płynięcia zbrojenia podłużnego. W pierwszej kolejności przeprowadzono badania laboratoryjne na belkach żelbetowych ze strzemionami. Ze względu na brak podobieństwa geometrycznego zaobserwowano dwa odrębne tryby zniszczenia w zależności od relacji rozpiętości ścinania do wysokości belki. W eksperymentach dominował tryb zniszczenia przy ścinaniu-ściskaniu dla małych wartości tej relacji oraz kruszenie betonu w strefie ściskania dla dużych wartości. Następnie wykonano obliczenia metodą elementów skończonych (MES) do bezpośredniej symulacji doswiadczeń. Zastosowano dla betonu sprzężony izotropowy sprężysto-plastyczny model konstytutywny z degradacją sztywności w warunkach stanu płaskich naprężeń. Konstytutywny model został wzbogacony o nielokalność typu integralnego w reżimie osłabienia, aby zapewnić obiektywne wyniki numeryczne. Założono prawo kontaktu typu poślizgowego pomiędzy betonem a prętami podłużnymi. Symulacje numeryczne w warunkach naprężeń płaskich warunki realistycznie odtworzyły eksperymentalne wytrzymałości na ścinanie i tryby zniszczenia dla wszystkich belek dla tego samego zestawu parametrów wejściowych. Wykonano szerokie badania parametryczne dotyczące numerycznego wpływu zbrojenia podłużnego i poprzecznego oraz relacji rozpiętości ścinania do wysokosci na wytrzymałości belek i sposoby ich zniszczenia. Dodatkowo wykonano również w celach porównawczych jedno pełne obliczenie trójwymiarowe.
Experimental investigations and damage growth modeling of EN‐AW 2024 aluminum alloy under LCF loading accounting creep pre‐deformation
- Adam Tomczyk
- Andrzej Seweryn
2022 Full text FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
This article presents the results of experimental tests of creep rupture and of low-cycle fatigue (LCF) of EN-AW 2024 aluminum alloy devoid of damage and having preliminary damage. The preliminary damage was dealt in the process of creep at elevated temperature 100C, 200C, and 300C until achievement of two different strain values at each temperature. Samples with preliminary damage were subjected to fatigue tests at room temperature. Based on the results of experimental tests, a simple damage accumulation model was proposed for creep at different temperatures. In this model, growth of the damage state variable was made dependent on the current value of axial stress and on growth of plastic strain. This model was also adapted for description of damage accumulation in the process of LCF for both as-received material and material with creep pre-deformation. In both cases, that is, creep and LCF, the model's parameters were determined and it was experimentally verified.
Experimental research on a hydrodynamic thrust bearing with hydrostatic lift pockets: Influence of lubrication modes on bearing performance
- J. Bouyer
- Michał Wodtke
- Michel Fillon
2022 TRIBOLOGY INTERNATIONAL
The aim of the study is to investigate the performance of a thrust bearing equipped with hydrostatic lift pockets under different lubrication modes. Three types of flat land bearing lubrication modes are studied experimentally: hydrostatic lubrication (HS; forced oil injection to the pockets), hybrid lubrication (HS + HD; hydrostatic lubrication combined with the external forced bearing oil supply) and hydrodynamic lubrication (HD; external forced bearing lubrication acting alone). Tests are performed for steady and transient states of bearing operation. The obtained results confirmed that the load- carrying capacity of the flat land bearing is poor, and the introduction of hydrostatic lubrication improves its performance. The speed is found to be a critical parameter: as it increases, the hydrostatic effect is affected and the film thickness is educed.
Experimental-Numerical Analysis of the Effect of Bar Diameter on Bond in Pull-Out Test
- Marcin Burdziński
- Maciej Niedostatkiewicz
2022 Full text Buildings
Bar diameter is one of the basic factors affecting bond behavior, which is still of interest due to opposing opinions regarding its effect on bond behavior in the pull-out test. This paper presents an experimental and numerical bond analysis of ribbed reinforcing bar in concrete. The aim was to experimentally evaluate the effect of bar diameter on the bond behavior in the pull-out test and to perform numerical simulations of the conducted experiments in ABAQUS to verify their convergence to the obtained experimental results. The experiments used concrete of C35/45 grade and B500SP reinforcing steel bars of three diameters: 10, 12, and 16 mm. FEA simulations employed the Concrete Damaged Plasticity (CDP) material model and the Contact Cohesive Behavior (CCB) method to model the concrete–bar interface. The study shows that bar diameter significantly affects the bond, both on the bond stress–slip relationship and the type of bond failure, as well as on the bond strength. FEA simulations correctly reflected the bond behavior observed in the specimens. The analytical models presented estimates that were too conservative regarding the maximum bond stress relative to the experimental results.
Experiment-Based Study of Heat Dissipation from the Power Cable in a Casing Pipe
- Romuald Masnicki
- Janusz Mindykowski
- Beata Pałczyńska
2022 Full text ENERGIES
The paper deals with the important challenges in terms of electricity transmission by means of underground cable lines. The power cable’s performance is characterized by an ampacity that represents its maximum electric current-carrying capacity. The ampacity of power cables depends on their ability to diffuse the heat generated by the current flow into the environment. In the performed research, the analysis of the efficiency of heat dissipation from the cable is based on the measurement of temperatures at selected points in individual sections of the cable. As a consequence, the proposed test stand and applied research methodology are vital for the experimental evaluation of the analyzed thermal phenomena in the investigated underground cable lines. The research program covers an in-depth analysis based on the results related to the vital parameters of the investigated cable. The experimental methodology was used to analyze the influence of the properties of the medium surrounding the cable on its temperature, and thus on the ampacity of the cable. A novelty of this paper concerns the carrying out of the experimental laboratory research with actual measurements of the temperature distribution in specific points of the casing pipe based on the original test stand. The paper presents the novel concept of the developed stand for testing heat dissipation from the cable in a casing pipe with pipe sections filled with various media, equipped with a power supply system ensuring easy control of the power dissipated in the cable. The preliminary results of the comparative tests, in which the temperature distribution in the sections of the casing pipes was recorded, indicate that the findings are satisfactorily consistent with the assumptions related to the purpose of the research. The use of appropriate materials surrounding the cable contributes to more effective heat dissipation, and as it has been shown for the examined case in originally planned and conducted tests, it can lower the cable temperature by more than 20 °C, contributing to a significant increase in the ampacity of the cable. For example, it was recorded that for different media filling the pipes, the cable reached 30 °C with different currents flowing through cables of 60 A and 120 A, respectively.