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Green's functions for the static curvature and deflection of two-phase peridynamic elastic Euler-Bernoulli beams with exponential kernels
No full textInternational audienc
A solar-powered multi-functional portable charging device (SPMFPCD) with internet-of-things (IoT)-based real-time monitoring—An innovative scheme towards energy access and management
No full textInternational audienceBattery energy storage system (BESS) Internet of thing (IoT) Real-time monitoring Disaster management technology Economic viability Emergency medical charging solutions Mul-ti-functional charging device Public spaces charging infrastructure Renewable energy integration (REI) Solar-powered portable charging In the absence of portable charging devices, sectors such as transportation, communication, and emergency services deal with various challenges towards electric power needs while compromising on (1) operational efficiency, (2) insufficient portable charging solutions, and (3) limited versatility. This highlights the critical need for reliable and multi-functional power solutions. To provide a portable charging solution across diverse sectors, this paper proposes an innovative development of a solar-powered multi-functional portable charging device (SPMFPCD) with internet-of-thing (IoT)-based monitoring capabilities. The proposed scheme introduces a comprehensive model integrating advanced technologies which include a highly efficient solar panel, charge controller, sensors, and IoT module. The proposed system facilitates versatile charging solutions for a wide range of power requirements with real-time monitoring and data analysis through the IoT platform. Moreover, the proposed work explores the applications of the SPMFPCD in (1) emergency medical scenarios, (2) outdoor adventures, (3) disaster management, and 4) public spaces. Performance evaluation was made by proposing case studies to validate the (1) economic viability, (2) power management, and (3) environmental impact of widespread deployment of SPMPFCD in public spaces. Furthermore, detailed analysis of battery energy storage system (BESS) and photovoltaic (PV) integration for load management, seasonal dynamics, and renewable energy integration (REI) contribute to a comprehensive understanding of the proposed solution
An Improved Sensorless Method to Submodule Voltage Balancing in Grid‐Connected Modular Multilevel Converters
No full textInternational audienceABSTRACT This article proposes an improved sensorless capacitor voltage balancing (CVB) method for modular multilevel converters (MMCs) for high‐voltage direct current applications. The suggested method prioritizes achieving precise, straightforward, and computationally efficient control of MMCs, eliminating the necessity for external sensors. Simultaneously, it guarantees effective management of capacitor voltage balance within the converter arms. Combining the proposed sensorless control technique and CVB methods improves converter performance, reduces complexity, and increases overall system reliability. To validate the effectiveness of the proposed strategy, full simulations are performed. The simulation setup includes the MMC structure, the control algorithm, and the sensorless CVB method. The simulation results demonstrate the accurate regulation of energy flow while maintaining balanced capacitor voltages between the arms of the MMC. In addition, experimental verification is carried out using a scaled‐down laboratory prototype of the MMC system. The experimental results validate the practical feasibility and reliability of the proposed control strategy
Thermoplastic Alternatives to Thermosets in Type IV COPVs : A Review of Materials, Manufacturing, and Performance for Hydrogen Storage
No full textInternational audienceABSTRACT The rapid expansion of hydrogen‐powered technologies has developed the need for lightweight, high‐performance storage solutions. Composite overwrapped pressure vessels (COPVs), particularly Type IV designs featuring polymer liners and carbon‐fiber reinforcements, represent the most widely used means of on‐board hydrogen storage due to their exceptional strength‐to‐weight ratios and fatigue resistance. However, conventional thermosetting epoxies, while offering excellent processability, pose significant recyclability challenges amid escalating sustainability and ecology requirements. This review critically examines the state of the art in composite materials for hydrogen tanks, with a special focus on Elium liquid thermoplastic resin as an eco‐friendly alternative. The principal filament winding techniques, namely wet winding, dry winding, towpreg winding, and thermoplastic prepreg winding with in situ consolidation, are systematically reviewed and comparatively analyzed in terms of their processing characteristics, compatibility with resin systems, and resulting composite quality. Recent advancements in the optimization of filament winding process parameters, such as fiber tension, winding angle, and geometry factors, are critically examined for their direct influence on key performance indicators, including burst pressure (the maximum internal pressure a tank can withstand before catastrophic failure) and structural weight. By synthesizing recent advances in materials, processing parameters, and performance metrics, this review outlines a roadmap toward fully recyclable, high‐integrity hydrogen storage solutions
Dynamic Impedance Spectrum: A Novel Metric for Lithium-Ion Batteries Overcharging Diagnosis
No full textInternational audienceDiagnosis of overcharging in lithium-ion batteries (LIBs) is crucial to guaranteeing the long-term thermal stability and operational lifespan of a battery system. Compared with conventional diagnosis methods that rely on cell temperature and voltage measurements, the dynamic impedance spectrum (DIS) provides novel insights into assessing battery charging and overcharging processes. In this article, the perturbation signals are superimposed onto the charging current for the real-time monitoring of the dynamic impedance variation. A quantitative analysis is conducted to examine the applicability of the characteristic parameters, which are extracted by fitting the DIS with an equivalent circuit model (ECM), in assessing the overcharging in LIBs. Experimental investigations confirm the validity of the DIS measurements by performing the Kramers-Kronig (K-K) tests, where the maximum absolute residuals are lower than 0.5%. The proposed method is capable of reliably warning the battery overcharge when the batteries are charged up to 98% state of charg
RegStack machine learning model for accurate prediction of tidal stream turbine performance and biofouling
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Interfacial fracture in soft solids -how geometry and viscoplasticity make crack fronts unstable
No full textInternational audiencePolyvinylbutyral (PVB) is a polymer with sizeable viscoelastic dissipation at room temperature. It is often used in laminated glass to impart shock resistance to glazings. We have investigated adhesion rupture in glass/PVB interfaces in the through crack tensile test (TCT) geometry, representative of laminated glass rupture. We find that even though, in the high velocity range, interfacial rupture apparently follows the linear viscoelastic predictions, at low velocity a much richer behaviour appears: the system bifurcates, the front undulates, and at still lower velocities, it stops. Such instabilities cannot be explained by linear viscoelastic fracture. Prompted by the measured tensile response of PVB at high strain rates/low temperatures, we have explored steady state viscoplastic fracture, using a generic numerical model. The results show that the TCT geometry enhances the viscoplastic response in the rupture process. They also demonstrate that with viscoplasticity, the rupture energy decreases with velocity, a characteristic which indeed accounts for the observed crack front instabilities. We further discuss the implications of these findings for a better understanding of adhesion and rupture in soft matter and their connection to viscoplasticity
The Gasification of Marine and Coastal Resources for Syngas Production: A Review
No full textInternational audienceCoasts are home to one-third of the human population. In the process of energy transition, local biomass and waste resources represent a renewable fuel that can substitute fossil fuels in order to reduce greenhouse gas emissions, hence including marine resources as part of the eligible feedstock for renewable energy production. Gasification regroups different technologies that aim to convert a solid fuel into a useful gas, and has several applications, such as heat production, power generation, and chemical synthesis. Gasification technologies regroup the traditional “dry” processes that use relatively dry fuels, but recent developments have been made with “wet” processes such as hydrothermal gasification, in sub- or supercritical conditions for the water, which can accept wet fuel. This review focuses on scientific articles that performed gasification of marine resources in order to produce a syngas. First, a definition of marine resources is made, followed by the presentation of marine resources studied in the literature. Secondly, this review presents the different types of gasification reactors and their operating conditions, followed by a summary of the different syngas produced with their composition as a performance indicator. Finally, this review exposes the limitations of the current literature and concludes with perspective propositions
RILEM TC 275-HDB: results of interlaboratory testing for determining capillarity properties of hemp concrete
No full textInternational audienceThis report presents a new proposal for conducting the water capillary absorption test of hemp concretes and establishing the parameters useful for analyzing the obtained results. Based on the standards of traditional materials such as concrete and mortar, a testing protocol was developed and executed by eight laboratories from RILEM TC 275-HDB through interlaboratory testing. Homogeneous cubic specimens of hemp concrete with an edge length of 150 mm were cast and distributed to the laboratories, where they were conditioned before undergoing test. By adopting the new testing procedure, consistent results were achieved after analyzing data in both square root of time and log-time regimes. For each regime, two pairs of parameters CA and k (square root of time regime), and IRA and K1 (log-time regime) were utilized to compare the data and successfully validate the interlaboratory testing
Buckling of Simply Supported Bi-Periodic Elastic Columns
No full textInternational audienceIn this paper, the buckling of a simply supported stepped periodic column is studied using an analytical method. The column is composed of biperiodic cells of stepped Euler–Bernoulli continuous segments. The deflection solution in each cell can be expressed from the resolution of a fourth-order differential equation. After expressing the continuity conditions between each cell, it is possible to relate the solution of each cell with respect to its neighbors. The differential eigenvalue problem of the bi-periodic structure is converted into a linear difference eigenvalue problem associated to the coefficients of the expressed solution in each cell. A transcendental equation for the buckling load of the continuous biperiodic column is obtained from the resolution of the discrete linear difference eigenvalue problem. This transcendental equation is valid whatever the number [Formula: see text] of bi-periodic cells, with [Formula: see text] larger than 2. This general expression is corroborated with the buckling values obtained using a direct method for few cells ([Formula: see text] and [Formula: see text] for instance). The behavior of the stability limit for large [Formula: see text] values is also specifically studied. It is shown that the bi-periodic column asymptotically converges toward a homogenized Euler–Bernoulli column with equivalent stiffness calibrated from Reuss’s averaging method. More refined beam models are also derived using asymptotic arguments. The buckling load converges toward the one of a gradient beam model for sufficiently large number [Formula: see text] of cells, which can be equivalently derived from a second-order homogenized beam theory. The convergence of this second-order homogenized beam model toward the equivalent homogenized Euler–Bernoulli column (obtained from Reuss’s averaging method) is from below, as also reported for the exact solution of the biperiodic continuous column. A comparison is also carried out for large values of [Formula: see text] with a nonlocal Euler–Bernoulli model, which has the same order of accuracy as obtained from the gradient beam model (second-order homogenized beam model)