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Understanding forest water limitation during droughts within a warming climate is essential for accurate predictions of forest-climate interactions. In hyperdiverse ecosystems like the Amazon forest, the mechanisms shaping hysteresis patterns in transpiration relative to environmental factors are not well understood. From this perspective, we investigated these dynamics by conducting in situ leaf-level measurements throughout and after the 2015 El Niño-Southern Oscillation (ENSO) drought. Our findings indicate a substantial increase in the hysteresis area (Harea) among transpiration (E), vapor pressure deficit (VPD), and stomatal conductance (gs) at canopy level during the ENSO peak, attributed to both temporal lag and differences in magnitude between gs and VPD peaks. Specifically, the canopy species Pouteria anomala exhibited an increased Harea, due to earlier maximum gs rates leading to a greater temporal lag with VPD compared to the post-drought period. Additionally, leaf water potential (ΨL) and canopy temperature (Tcanopy) showed larger Harea during the ENSO peak compared to post-drought conditions across all studied species, suggesting that stomatal closure, particularly during the afternoon, acts to minimize water loss and may explain the counterclockwise hysteresis observed between ΨL and Tcanopy. The pronounced Harea during the drought points to a potential imbalance between water supply and demand, underlining the role of stomatal behavior of isohydric species in response to drought.

Our study delves into analyzing fatigue damage in notched structures, an essential field in structural mechanics. We aim to understand how geometric and dimensional variations in the notches affect fatigue damage under different modes and amplitudes of cyclic loading, focussing on the behavior of steel. Our research methodology integrates experimental and numerical approaches. Experimental validation encompasses material properties, mesh selection, and boundary conditions. The finite element method is tailored to address steel's elastoplastic behavior, employing calibrated parameters for kinematic and isotropic cyclic hardening models within the numerical realm. Specific findings elucidate the cyclic response of notched structures, tracking damage progression to critical thresholds, including the number of cycles to failure (Nf) and the critical crack length (Lc). Hysteresis curves vividly depict stress–strain relationships, offering insight into material behavior under cyclic loading. Implications span engineering domains, focussing on reliability and durability in the aerospace, automotive, and civil engineering sectors. Future directions include real-world applications and advanced techniques such as the Extended Finite Element Method (XFEM). In conclusion, this research enriches our understanding of fatigue damage analysis in notched structures, poised to impact safety and robust engineering design. [ABSTRACT FROM AUTHOR]

In this paper, a new micromechanical hysteresis loop constitutive model of C/SiC composites with different interphases was developed considering the probabilistic‐statistical matrix fragmentation process. The lengths of matrix fragmentation were divided into three types, that is, long matrix fragments (LMFs), medium matrix fragments (MMFs), and short matrix fragments (SMFs). The distributions of the LMFs, MMFs, and SMFs with increasing tensile stress were determined using the probabilistic‐stochastic model by assuming the two‐parameter matrix strength distribution. The micro stress field of the LMFs, MMFs, and SMFs upon unloading and reloading was obtained and adopted to determine the corresponding stress‐strain relations. The interaction of matrix fragmentation lengths, especially for the LMFs with large debonding energy (LDE) and SMFs, was considered in the closed‐form constitutive model and hysteresis‐based inverse tangent modulus (ITMs) damage parameter. Synergistic effects of the fiber volumes, peak stresses, and interface debonding energy on the interface damage state, mechanical hysteresis loops, and related ITMs with small debonding energy and LDE were also analyzed. Comparisons of the mechanical hysteresis loops using the new hysteresis models considering matrix stochastic fragmentation and hysteresis models considering constant matrix fragmentation were also discussed. Experimental cyclic tensile hysteresis loops and unloading/reloading ITMs of C/(PyC)/SiC and C/(PyC+SiC)/SiC composites with different interphase thickness (i.e., t = 300, 600, 1000, and 2000 nm) were predicted using the developed constitutive model. Evolution of the unloading/reloading interface slip ratio was analyzed for different tensile peak stresses. [ABSTRACT FROM AUTHOR]

The Monte Carlo studies presented in this paper provide insight into stable phases, magnetic hysteresis cycles and magnetization plateaus in mixed nano-Kagome bilayer lattices. In particular, exchange coupling reduction affects coercive and saturation fields, and temperature variations impact hysteresis loop regions. The role of the crystal field in the design of magnetization plateaus was highlighted. The study explores the interaction of magnetization plates and their response to critical and saturation fields, depending on the crystal field and ferrielectric coupling. Extremely low temperatures (T = 0. 0 1) play a crucial role in the manifestation of magnetization plateaus. These results suggest possible applications in nanotechnology, particularly in the design of storage media. [ABSTRACT FROM AUTHOR]

The current study investigated the magnetic features of a bilayer MXene-inspired nanostructure through Monte Carlo investigations. Identification of 24 stable spin configurations with varying the coupling parameters (Jss and Jσσ) revealed the influence of these parameters on the magnetic phase region. Additionally, the study explored the impact of coupling parameter (JσS) and external magnetic field (H) on the blocking temperature, highlighting the more significant role played by JσS. Furthermore, the analysis considered how JσS and temperature (T) affect multiple hysteresis loops, including size, coercive field and saturation field. These results have hold important implications for magnetic MXene nanostructures and multistate memory storage applications. [ABSTRACT FROM AUTHOR]

This paper presents selected results of experimental tests on multi-leaf springs used in the dependent suspensions of trucks. The main objective of this research was to determine the dissipation energy in the actual spring structure for various methods of mounting the spring in the vehicle supporting system, with quasi-static vertical loading. Two basic methods of spring cooperation in a dependent suspension were tested: a free spring and a spring with a hanger. The experimental test conditions took into account different loading (unloading) speeds and changes in the angle of the hanger in relation to the frame and changes in its length. Based on the results of experimental tests, the elastic characteristics of springs with a hysteresis loop were developed. Load energy and dispersion values were calculated from the curves using the numerical integration method. The test results are presented in the form of elastic characteristics of springs with a hysteresis loop and comparative diagrams of load and dissipation energy. The original aspects of this work include the design, the construction of the stand and the methodology of experimental tests of the multi-leaf springs together with a comparative analysis of the test results and conclusions. [ABSTRACT FROM AUTHOR]

The impact of dynamic processes on equilibrium properties is a fundamental issue in condensed matter physics. This study investigates the intrinsic ferromagnetism generated by memory effects in the low-dimensional continuous symmetry Landau–Ginzburg model, demonstrating how memory effects can suppress fluctuations and stabilize long-range magnetic order. Our results provide compelling evidence that tuning dynamical processes can significantly alter the behavior of systems in equilibrium. We quantitatively evaluate how the emergence of the ferromagnetic phase depends on memory effects and confirm the presence of ferromagnetism through simulations of hysteresis loops, spontaneous magnetization, and magnetic domain structures in the 1D continuous symmetry Landau–Ginzburg model. This research offers both theoretical and numerical insights for identifying new phases of matter by dynamically modifying equilibrium properties. [ABSTRACT FROM AUTHOR]

Although the impacts of climate change are long-term in nature, the transformation in climate regime can lead to an ecosystem change from one stable to another stable state through intermediate bistable or metastable states. Such state transition or resilience to change in ecosystems is seldom sharp and therefore difficult to quantify with a single tipping point. Rather, the change can be understood through a tipping point range (tipping zone) across hysteresis loop(s). This study uses a satellite data-derived actual vegetation cover map of India and categorizes it into different vegetation types: forest, scrubland, grassland, and vegetation-less. We used high-resolution long-term average precipitation data to develop moisture-driven hysteresis curves and predict various tipping point ranges for vegetation-type regime shifts. Our results reveal that the forest and vegetation-less states could have one-way, while scrubland and grassland have two-way transition probabilities with a probable shift in precipitation regime. In the dry conditions, the precipitation tipping zone predicted between 154 and 452 mm for the forest to scrubland transitions, while the reverse transition (from scrubland to forest) could occur in wet conditions between 1080 and 1400 mm. Similarly, the transition between scrubland and grassland, between grassland and vegetation-less state, may occur in contrasting dry and wet conditions, creating a hysteresis loop. The results indicate that the reversal of state change requires differential energy spent during the onward and reverse transitions. The study proposes a novel characteristic curve demonstrating the varied precipitation tipping points/zones, precipitation overlaps and distribution of the various vegetation types, and co-existence zones, which has huge implications for understanding the climate change impacts. [ABSTRACT FROM AUTHOR]

The increasing frequency of extreme weather events, such as hurricanes and rising sea levels due to climate change, presents significant challenges to coastal infrastructure. With 42% of bridges in the United States exceeding 50 years of age, which surpasses their intended service life, there is a pressing need to assess their structural integrity, especially in coastal regions. This study focuses on evaluating the structural performance of bearing pads in coastal bridges under hurricane-induced wave loadings. Utilizing a combination of physics-based models (PBM), nonlinear modal time history analysis, and numerical validation, the research examines the hysteresis response of eight distinct bearing pad configurations. The findings indicate that reinforced circular bearing pads exhibit significantly greater shear displacements compared to plain elastomeric pads, underscoring the critical influence of shape factors on shear response. Fragility functions developed in the study illustrate the probability of shear failure, with reinforced circular pads showing a 28% higher likelihood of exceedance compared to rectangular plain pads. These results highlight the necessity for advanced design methodologies specifically for bearing pads to enhance the resilience of coastal infrastructure against severe hydrodynamic forces induced by hurricanes. [ABSTRACT FROM AUTHOR]

Abstract The increasing frequency of extreme weather events, such as hurricanes and rising sea levels due to climate change, presents significant challenges to coastal infrastructure. With 42% of bridges in the United States exceeding 50 years of age, which surpasses their intended service life, there is a pressing need to assess their structural integrity, especially in coastal regions. This study focuses on evaluating the structural performance of bearing pads in coastal bridges under hurricane-induced wave loadings. Utilizing a combination of physics-based models (PBM), nonlinear modal time history analysis, and numerical validation, the research examines the hysteresis response of eight distinct bearing pad configurations. The findings indicate that reinforced circular bearing pads exhibit significantly greater shear displacements compared to plain elastomeric pads, underscoring the critical influence of shape factors on shear response. Fragility functions developed in the study illustrate the probability of shear failure, with reinforced circular pads showing a 28% higher likelihood of exceedance compared to rectangular plain pads. These results highlight the necessity for advanced design methodologies specifically for bearing pads to enhance the resilience of coastal infrastructure against severe hydrodynamic forces induced by hurricanes.

Abstract The paper deals with the economic optimisation of ferrite powder preparation during producing hard ferrite magnets. The magnetic properties of ferrites are investigated by replacing feedstock and reducing calcination temperature and particles in the order of tens of microns. The granulates about 8–10 mm in size were calcined for 2 h in the temperature range from 1100 °C to 1300 °C and additionally crushed and milled to an average particle size of about 80–90 µm. The scanning electron microscopy images confirmed the agglomerates of particles with different shapes and sizes in tens of µm. The X-ray diffraction measurements revealed that, besides the SrFe12O19 and BaFe12O19 phases, there was also the presence of 2–39% hematite. The highest values of maximum energy product (BH)max = 930 J/m3 and remanent magnetic induction Br = 72.8 mT were obtained at a calcination temperature of 1300 °C. The Henkel plots confirmed the presence of exchange-coupling and dipolar magnetic interactions at lower and higher magnetic fields, respectively. The strength of interactions was also dependent on the calcination temperature. Replacing strontium with barium led to a deterioration of the magnetic parameters, which were optimal at a lower calcination temperature (1100 °C). This phenomenon was partly overcome by reducing the mean particle size of Ba-based hexaferrites to 45–50 µm.

Bolted joints are widely used in various engineering structures. The bolted joint may become loosening under long-term oscillating load, and cause reciprocating friction between the contact interfaces. Acoustic emission (AE) is a phenomenon of rapid release of transient elastic waves, which will be generated continuously during the reciprocating friction. The friction conditions will affect the characteristics of the contact interface and the related AE signals. Therefore, analyzing the quantitative relationship between friction conditions and AE signal is significant for applying AE technique in bolt loosening monitoring. However, researches on the relationship between AE Vrms and friction operating parameters are mostly focused on rotating machineries currently, whether the obtained conclusions are suitable for bolted joints is not clear. This paper finds that the commonly used quantitative relationship between the AE Vrms and friction operating parameters is not suitable for bolted joint structures by comparing the theoretical and experimental AE Vrms. The relationship is then modified through exponential parameter fitting and verified using the same experiments in this paper. The results show that the modified equation can accurately describe the quantitative relationship between the AE Vrms and the friction operating parameters, thus revealing the mechanism of acoustic emission signals generated during the gross-slip. [ABSTRACT FROM AUTHOR]

The dielectric properties of a mixed Zethrene-inspired nanoscale system ( S i Z -1, σ k Z -5/2) have been analyzed in detail using the Monte Carlo approach (MCa) in this study. First, the most stable configurations in different planes were investigated. Then, the influences of the physical factors, namely the coupling interaction factor, on the thermal behaviors of the polarization and the susceptibility of the studied nanostructure have been examined for nonzero temperatures and fixed external electric field values. It was found that the obtained transition temperature point relies weakly on the coupling interaction. Finally, the effects of the physical factors on the electric hysteresis cycles were discussed. [ABSTRACT FROM AUTHOR]

In this paper, the influence of interphase type (i.e. single-phase (PyC) and co-deposited (PyC+SiC)) and thickness (i.e. 300, 600, 1000, and 2000 nm) on the interface properties and damage evolution of mini-C/SiC composites under cyclic loading/unloading tension was investigated. The micromechanical constitutive model was adopted to derive the damage parameter of inverse tangent modulus (ITM) and perform the hysteresis analysis to estimate the interface properties of the mini-C/SiC composites with large debonding energy. Experimental damage evolution of the ITMs with unloading or reloading stress was analyzed for different interphase types and thickness. The interface properties (e.g. the interface debonding stress and interface debonding energy) were obtained through the hysteresis analysis. Relationships between the loading/unloading ITMs, interface properties, and interphase type and thickness were established. [ABSTRACT FROM AUTHOR]

This study employs comprehensive Monte Carlo simulations to gain detailed insights into the dielectric response of borophene core–shell structures. Key parameters, including exchange coupling interactions, external electric fields, temperature, and crystal fields, were systematically explored, providing a nuanced understanding of the system's behavior. The dynamics revealed by this study lays the foundation for future research, guiding efforts toward optimizing and customizing the dielectric properties of this structure. This exploration holds promise for potential applications tailored to sophisticated electronic devices. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to forecasting the evolution of hysteresis stress-strain response of different types of soils under repeated loading-unloading cycles. The forecasting is made solely from the knowledge of soil properties and loading parameters. Our approach combines mathematical modeling, regression analysis, and Deep Neural Networks (DNNs) to overcome the limitations of traditional DNN training. As a novelty, we propose a hysteresis loop evolution equation and design a family of DNNs to determine the parameters of this equation. Knowing the nature of the phenomenon, we can impose certain solution types and narrow the range of values, enabling the use of a very simple and efficient DNN model. The experimental data used to develop and test the model was obtained through Torsional Shear (TS) tests on soil samples. The model demonstrated high accuracy, with an average R² value of 0.9788 for testing and 0.9944 for training. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of the magnetic and magnetocaloric properties of a mixed Graphullerene-like nanostructure. The Blume–Capel model is employed, and Monte Carlo computations were performed using the Metropolis algorithm. The study examines various spin configurations within different parameter planes and reveals stable configurations. Furthermore, the paper analyzes magnetizations, susceptibilities, specific heat, and Binder cumulant as a function of the temperature to determine the transition temperature and characterize magnetic phase transitions in the system. The suitability of the investigated structure for magnetic refrigeration was also assessed by examining the magnetic entropy change and relative cooling power at different external magnetic field strengths. The results show a direct correlation between the external magnetic field and maximum entropy changes, indicating a significant magnetocaloric effect. [ABSTRACT FROM AUTHOR]

The magnetic properties and hysteresis loops for the hexagonal Ising nanowire (HIN) with a core-shell structure consisting of mixed spins with the core spin being spin-5/2 and the shell spins being spin-3/2 are studied. The Blume-Capel model is considered by using the mean-field approximation (MFA) based on the Gibbs-Bogoliubov inequality for free energy. The impact of different bilinear interaction parameters (JCC, JSS, JCS) between the core, shell, and core and shell spins, respectively, including the crystal (DC, DS) and external magnetic fields (h = hc = hs) at the core and shell sites, are taken into consideration. In order to obtain phase diagrams on various planes, the thermal changes of the net, core, and shell magnetizations are investigated for various values of our system parameters. It is discovered that the model exhibits only second-order phase transitions when h = 0.0 for D greater or equal to zero, first- and second-order phase transitions for h ≠ 0.0 and compensation temperatures for all h. [ABSTRACT FROM AUTHOR]

Historical masonry structures are the most important features that distinguish our cultural heritage, from here comes the importance of protection this type of masonry structures from collapse under earthquakes effect or other dynamic loading such as blast loading. Therefore, Seismic Base Isolation is used to reduce earthquakes damages and protect structures from collapse. This paper aims to study the Effect of Seismic Base Isolation, using High Damping Rubber Bearing (HDRB) on Existing Masonry Structures subjected to dynamic loads such as earthquakes, through utilizing numerical modeling of masonry structures. This paper includes definition of seismic base isolation mechanical characteristics, and definition of numerical modeling approaches for structural masonry analysis. The studied masonry structure is the old AWQAF Directorate Building in Aleppo, which is islamic government building affiliated to the Syrian Ministry of AWQAF; In order to perform the numerical modeling, equivalent masonry properties used for this structure were also determined. This structure was analyzed applying nonlinear dynamic analysis-time history method, and reanalyzing it by using seismic base isolation, type HDRB applying the same method. The results of the two analyses were discussed and compared, and the conclusions of this paper showed reduction in shear force when using seismic base isolation, and reduction in stresses that appear in structure because the stresses are located in the level of base isolation system. [ABSTRACT FROM AUTHOR]

This paper presents selected results of experimental tests on multi-leaf springs used in the dependent suspensions of trucks. The main objective of this research was to determine the dissipation energy in the actual spring structure for various methods of mounting the spring in the vehicle supporting system, with quasi-static vertical loading. Two basic methods of spring cooperation in a dependent suspension were tested: a free spring and a spring with a hanger. The experimental test conditions took into account different loading (unloading) speeds and changes in the angle of the hanger in relation to the frame and changes in its length. Based on the results of experimental tests, the elastic characteristics of springs with a hysteresis loop were developed. Load energy and dispersion values were calculated from the curves using the numerical integration method. The test results are presented in the form of elastic characteristics of springs with a hysteresis loop and comparative diagrams of load and dissipation energy. The original aspects of this work include the design, the construction of the stand and the methodology of experimental tests of the multi-leaf springs together with a comparative analysis of the test results and conclusions.

The impact of dynamic processes on equilibrium properties is a fundamental issue in condensed matter physics. This study investigates the intrinsic ferromagnetism generated by memory effects in the low-dimensional continuous symmetry Landau–Ginzburg model, demonstrating how memory effects can suppress fluctuations and stabilize long-range magnetic order. Our results provide compelling evidence that tuning dynamical processes can significantly alter the behavior of systems in equilibrium. We quantitatively evaluate how the emergence of the ferromagnetic phase depends on memory effects and confirm the presence of ferromagnetism through simulations of hysteresis loops, spontaneous magnetization, and magnetic domain structures in the 1D continuous symmetry Landau–Ginzburg model. This research offers both theoretical and numerical insights for identifying new phases of matter by dynamically modifying equilibrium properties.

Magnetic microwires with amorphous structures can present a unique combination of excellent magnetic softness and giant magnetoimpedance (GMI) effects together with reduced dimensions and good mechanical properties. Such unique properties make them suitable for various technological applications. The high GMI effect, observed in as-prepared Co-rich microwires, can be further optimized by postprocessing. However, unexpected magnetic hardening and a transformation of the linear hysteresis loop into a rectangular loop with a coercivity on the order of 90 A/m were observed in several Co-rich microwires upon conventional annealing. Several routes to improve magnetic softness and GMI effect in Fe- and Co-rich magnetic microwires are provided. We observed that stress annealing could remarkably improve the magnetic softness and GMI ratio of Co-rich microwires. Thus, almost unhysteretic loops with a coercivity of 2 A/m and a magnetic anisotropy field of about 70 A/m are achieved in Co-rich microwires stress annealed at appropriate conditions. The observed change in hysteresis loops and the GMI effect is explained by stress-annealing-induced anisotropy, which is affected by the stresses applied during annealing and by the annealing temperature. While as-prepared Fe-rich amorphous microwires present a low GMI effect, appropriate postprocessing (annealing and stress annealing) allows for a remarkable GMI ratio improvement (an order of magnitude). The evaluated dependence of the maximum GMI ratio on frequency allows the identification of the optimal frequency band for the studied samples. The origin of stress-annealing-induced anisotropy and related changes in hysteresis loops and the GMI effect are discussed in terms of the relaxation of internal stresses, "back-stresses", as well as structural anisotropy. [ABSTRACT FROM AUTHOR]

This manuscript presents a model and simulation of the copper chalcopyrite semiconductor CuGaSe2 in order to predict its magnetic properties. In the semiconductor material CuGaSe2 (CGS), the atom Cu is the only magnetic element with a magnetic moment value S = 1/2. We propose a Hamiltonian to calculate the energies corresponding to different configurations of the system. In a first step, we presented the magnetization behavior by using the Monte Carlo simulations (MCS). The magnetizations as a function of the temperature, the exchange coupling have been studied and discussed. We have also deduced and studied the magnetic susceptibilities. To complete this study, we have established and discussed the magnetic hysteresis loops of the studied compound. Finally, we have calculated the corresponding critical exponents and compared them with the standard 3D Ising model. [ABSTRACT FROM AUTHOR]

Under multi-step cyclic fatigue loading, the mechanical hysteresis loops of ceramic-matrix composites (CMCs) were affected by coupled multiple damage mechanisms. In this paper, the hysteresis-based inverse tangent modulus (ITMs) was developed to characterize the cyclic fatigue mechanical hysteresis behavior in 2D SiC/SiC composite under multi-step loading. The micromechanical multi-step hysteresis constitutive models were developed for the damage state of interface partial and complete debonding. Relationships between the cyclic-dependent interface wear, hysteresis loops, interface slip damage state, and ITMs were established. Effects of multi-step peak stress level, cycle number, and interface properties on the evolution of hysteresis stress-strain curves and ITMs were analyzed. Experimental multi-step cyclic fatigue hysteresis loops and ITMs of 2D SiC/SiC composite under different peak stresses of 1.2, 1.3, 1.4, and 1.5 PLS (proportional limit stress) were predicted. Compared with other hysteresis-based damage parameters, e.g., hysteresis width, hysteresis modulus, peak and residual strain, and loops area, the damage parameter of ITMs can better reveal the interface debonding and slip damage state in CMCs under multi-step cyclic fatigue loading. [ABSTRACT FROM AUTHOR]

We have examined the dynamic hysteresis characteristics and phase transition behavior of permalloy nanodisk with three different shapes, which are controlled by a metric order parameter, using the OOMMF micromagnetic simulation program based on the solution of the Landau-Lifshitz-Gilbert equation by finite difference numerical method approach. The hysteresis loop area, remanent magnetization, and coercive field values of the permalloy disk have been obtained as functions of the frequency and amplitude of the external sinusoidal magnetic field. In accordance with the simulation results obtained, a transition from a dynamically disordered phase to a dynamically ordered phase has been observed after a certain frequency value, and the phase transition region moved towards higher frequency values with increasing field amplitude. The triggered dynamical orders in other directions than the field have been observed for different frequency intervals. According to the shape effect of soft magnetic material, permalloy disk on dynamic behavior has been slowly reflected when the shape is concave. [ABSTRACT FROM AUTHOR]

The magnetic properties and hysteresis loops for the hexagonal Ising nanowire (HIN) with a core-shell structure consisting of mixed spins with the core spin being spin-5/2 and the shell spins being spin-3/2 are studied. The Blume-Capel model is considered by using the mean-field approximation (MFA) based on the Gibbs-Bogoliubov inequality for free energy. The impact of different bilinear interaction parameters (Jcc, Jss, Jcs) between the core, shell, and core and shell spins, respectively, including the crystal (Dc, Ds) and external magnetic fields (h = hc = hs) at the core and shell sites, are taken into consideration. In order to obtain phase diagrams on various planes, the thermal changes of the net, core, and shell magnetizations are investigated for various values of our system parameters. It is discovered that the model exhibits only second-order phase transitions when h = 0.0 for D greater or equal to zero, first- and second-order phase transitions for h ≠ 0.0 and compensation temperatures for all h.

This data article describes the extensive experimental dataset of friction hysteresis measured during the round robin test of the original research article [1]. The round robin test was performed on the two different fretting rigs of Imperial College London and Politecnico di Torino, and consisted of recording comparable friction hysteresis loops on specimen pairs manufactured from the same batch of raw stainless steel. The reciprocating motion of the specimens was performed at room temperature under a wide range of test conditions, including different normal loads, displacement amplitudes, nominal areas of contact and excitation frequencies of 100 Hz and 175 Hz. Friction forces and tangential relative displacements for each specimen pair were recorded and stored as hysteresis raw data. Each hysteresis loop was post-processed to extract friction coefficient, tangential contact stiffness and energy dissipated, whose evolution with wear was thus obtained and stored as well. MATLABⓇ scripts for post-processing and plotting data are included too.The dataset can be used by researchers as a benchmark to validate theoretical models or numerical simulations of friction hysteresis models and wear mechanisms, and also to study the physics of friction hysteresis and its contact parameters. This friction data can also be used as input in models for nonlinear dynamics applications as well as to provide information on the contact measurement uncertainty under fretting motion. Other applications include using this data as a training set for machine learning applications or data-driven models, as well as supporting grant applications.

Recent advancements in digitalization have resulted in the daily collection of vast amounts of data. To capitalize on this wealth of information, it is imperative to address multivariate issues, many of which are classified as NP-hard problems. One potential solution lies in metaheuristic optimization methods, which offer shorter search times and can generate approximate solutions. These techniques have seen applications across various domains. Nevertheless, a significant challenge posed by numerous representative metaheuristic methods involves the necessity for parameter configurations, the values of which notably impact convergence accuracy. This study proposes a novel optimization methodology grounded in metaheuristic optimization techniques that eliminate the need for problem-dependent accuracy affecting parameter settings. The authors assessed the efficacy of our method using standard benchmark functions and engineering benchmark problems. Furthermore, we employed it to search for multiple variables, such as historical curves, while conducting a nonlinear seismic response analysis in a real-world application scenario. Our findings confirm that our approach is not only more cost-effective but also superior in accuracy compared to previously used metaheuristic optimization methods.

The effect of the initial plastic deformation on the damping properties of low-carbon steel is experimentally studied, which corresponds to a change in the deformation diagram. The deformation diagram also refers to hysteresis loops that expand after the initial plastic deformation, called “plastic execution” in the work. When constructing hysteresis loops and recording damped oscillations, the amplitude values of loading cycles not exceeding 200 MPa are considered. Rods of rectangular box-shaped cross-section were used as samples. A description of static and dynamic laboratory installations that implement a pure bending scheme of the sample is given. Measurements are made by load cells with the fixation of counts in the computer memory with a frequency of 100 Hz. Cyclic symmetrical loads with a frequency of 2,62 Hz occur during oscillations in the sample. During the tests, the effect of a strong increase in hysteresis loops after the initial plastic deformation was reported to the sample was detected and quantitatively explored. The parameters of the loops are obtained depending on the value of the amplitude stress. The recorded graphs of decreasing amplitudes over time (up to 1000 periods) are in good agreement with the hysteresis loops obtained during static tests. The initial plastic deformation was also cyclic with deformation amplitudes 17% higher than the yield strength of the material. The effect of restoring the plastic deformation obtained by the sample after oscillations with stress amplitudes of 200 MPa was found. The oscillations cause the plastic deformation to be restored by more than 40%.

Based on the Ising model, Monte Carlo simulation (MCS) and the Mean-field approximation (MFA) were used to examine the magnetic properties and the phase diagram of a ferrimagnetic mixedspin (2,3/2) hexagonal Ising nanotube with core-shell structure. The effects of exchange interactions (Jint, Js) and the single-ion anisotropies (Ds, Dc) on the magnetization of the total system, the two sublattices and the hysteresis loops have been discussed in detail. The phase diagrams under the effect of different parameters have been provided. The results demonstrate the emergence of compensation phenomena as well as the second-order phase transitions. Multiple behaviors of hysteresis loop, including single and triple hysteresis loops, were identified as a result of competitions between various parameters. [ABSTRACT FROM AUTHOR]

Magnetic adaptive testing (MAT), thanks to its relative simplicity from the point of view of both hardware and software, appears to be very promising for non-destructive analysis of various ferromagnetic constructional materials used in many industrial applications. In order to make the inspection of tested objects faster, even more straightforward and the processing of data easier, we concentrated our effort both to improve the experimental procedure, based on specific way of the measurement of magnetization curves at piece-wise linear (triangular) exciting field with a constant field rate of change (i.e., slope) as well as to create a universal software tool for MAT data analysis. On contrary to the original implementation of MAT, the hysteresis loops are measured with decreasing maximum field values, starting at sample saturation region; therefore, time consuming sample demagnetization can be skipped completely. In addition, an advanced tool for the processing of experimentally obtained magnetization curves is presented. Using this application allows to find proper non-traditional magnetic parameters (e.g., the differential permeability) being the most sensitive to various types of industrial load (e.g., thermal, mechanical and/or neutron irradiation) and, at the same time, sufficiently correlated with other, traditional magnetic as well as non-magnetic parameters used routinely for the assessment of possible structural changes associated with applied, often long-term, load even on a microscopic scale, prior to any damage manifests on a macroscopic, visible level. The software capabilities were demonstrated on the data representing the material, whose response to acting thermal load is being difficult to analyze, since the dependence of observed parameters (differential permeability) upon defined artificial ageing was rather complicated. Nevertheless, the sensitivity of differential permeability to such a load was found being more than 8 times larger than in case of traditional hysteretic parameter, namely the remanent flux density while the correlation between them was high. [ABSTRACT FROM AUTHOR]

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We study the so-called self-polarization phenomenon in single, electroded PbTiO3 crystals. In this case, near the electrodes, surface layers are formed with a chemically modified perovskite structure. This generates a built-in electric polarization, which cannot be switched permanently by an external electric field. While the initial samples, having two such surface layers with opposite directions of built-in polarization, exhibit ordinary symmetric hysteresis loops, the "asymmetric" samples, with one of these surface layers removed, show asymmetric hysteresis loops. To describe our experimental findings, we combine two kinds of models: one is phenomenological, utilizing the above general features; and the other is ab initio, taking into account the actual atomic structure at the bulk ferroelectric–surface layer–electrode interface. Namely, the ab initio calculations show that the electric polarization within the surface layer occurs due to the shifts of the relaxed Ti ions with respect to the oxygen ion octahedra on the PbO-terminated surface. We ascribe the self-polarization effect to the occurrence of the built-in electric field resulting from the formation of Pb-O planes within the surface layer. [ABSTRACT FROM AUTHOR]

Shear modulus (SM) and damping ratio (DR) are significant in seismic design and the performance of geotechnical systems. The evaluation of soil reactions to dynamic loads, such as earthquakes, blasts, train, and traffic vibrations, necessitates the estimation of dynamic SM and DR. The aim of this research is to determine the cyclic parameters of unsaturated soils in and around Peshawar, and how these properties depend upon the varied confining pressures and shear strains. Undisturbed samples were collected using Shelby tubes from five boreholes at different locations along Jamrud Road, Peshawar. The index properties (grain size distribution, plasticity index, and specific gravity) and dynamic properties of these samples were determined. Three samples of 100 mm in height and 50 mm in diameter were obtained from each Shelby tube. After preparing and mounting the sample in the triaxial cell, the sample is first saturated by increasing the cell and back pressures in increments of 50 kPa until the value of Skempton's pore pressure parameter (B) reaches ≥ 0.96. Samples were consolidated at confining pressures of 150, 200, and 300 kPa, then subjected to cyclic shear strains of 0.2, 1, 2, 2.5, and 5%. Shear stress–strain hysteresis loops were plotted, and the values of SM and DR were calculated for each cycle. Generally, at shear strains of 0.2 and 1%, the slope of the loops is steep, and gradually becomes gentler at higher strains of 2, 2.5, and 5%. It is found that, with an increasing number of cycles, the SM and DR decrease. The SM decreases with increasing shear strain, whereas the DR increases at shear strains of 0.2–1%, then decreases for strains of 2, 2.5, and 5%. The confining pressure has more influence at a shear strain of 0.2–1%, while little effect has been observed at a shear strain of 2.2–5%. The values of SM are higher at higher confining pressures at a given shear strain. The results show higher stress values during the initial cycles because of the greater effective stress that developed in response to shear strain while, with an increase in the number of cycles, the pore water pressure gradually increases, thereby reducing the effective stress and weakening the bonds between soil particles. In dynamics, when the confining pressure increases, particles are closer to contact, so the travel paths of waves increase. The energy loss will increase, so DR will decrease. [ABSTRACT FROM AUTHOR]

In this study, we performed extensive Monte Carlo simulations to comprehensively analyze the magnetic properties of a single-layer MXene-like lattice. Our investigation involved the exploration of transition temperatures and the behavior of hysteresis cycles, all influenced by a series of key physical parameters. Additionally, we carefully mapped the magnetization as a function of temperature and crystal field, introducing variations in the exchange coupling to unveil their impact on the transition temperature. Furthermore, we investigated the behavior of hysteresis loops, complexly dissecting their responses to changes in exchange coupling, temperature, and crystal field. Significantly, our results highlight the central role of the crystal field in the formation of magnetization plateaus, thus providing promising avenues for applications in nanotechnology and advanced memory storage systems. [ABSTRACT FROM AUTHOR]

Thin films of BaM hexaferrite (BaFe12O19) were grown on α-Al2O3(0001) substrates by laser molecular beam epitaxy. Structural, magnetic, and magneto-optical properties were studied using medium-energy ion scattering, energy dispersive X-ray spectroscopy, atomic force microscopy, X-ray diffraction, magneto-optical spectroscopy, and magnetometric techniques, and the dynamics of magnetization by ferromagnetic resonance method. It was shown that even a short time annealing drastically changes the structural and magnetic properties of films. Only annealed films demonstrate magnetic hysteresis loops in PMOKE and VSM experiments. The shape of hysteresis loops depends on thickness of films showing practically rectangular loops and high value of remnant magnetization (Mr/Ms~99%) for thin films (50 nm) and much broader and sloped loops in thick (350–500 nm) films. The magnitude of magnetization 4πMs ≈ 4.3 kG in thin films corresponds to that in bulk BaM hexaferrite. Photon energy and sign of bands in magneto-optical spectra of thin films correspond to ones observed earlier in bulk samples and films of BaM hexaferrite. FMR spectra of 50 nm films at 50 GHz consist of a number of narrow lines. The width of main line ΔH~20 Oe is lower than has been reported up to now. [ABSTRACT FROM AUTHOR]

This study examined the effect of interchanging the position of (0°/90°) and (±45°) angle ply around the midplane of an eight‐layer symmetric [(0°/90°)/(±45°)2/(0°/90°)]s and asymmetric woven glass fiber reinforced composite laminate having [(0°/90°)/(±45°)2/(0°/90°)//(±45°)/(0°/90°)2/(±45°)] and (±45°)/(0°/90°)2/(±45°)//(0°/90°)/(±45°)2/(0°/90°) stacking sequence by means of flexure and fatigue test. The flexural and fatigue behavior of glass fiber–reinforced polymer (GFRP) laminates was analyzed as well. The GFRP laminates in varying stacking sequence having a volume fraction of 55 ± 0.9% were subjected to fatigue and damage analysis under stress levels ranging from 90% to 50% of their ultimate flexural strength at f = 1 Hz, R = 0.1. Flexure and fatigue testing was done in accordance with ASTM D790/D790‐17. The experiment results showed that the symmetric laminate with (0°/90°) ply at the compression and tension sides exhibited greater flexural strength (458.09 MPa) and fatigue lives as compared to the asymmetric A (352.70 MPa) and asymmetric B (272.89 MPa) laminates with (0°/90°) and (±45°) ply at the compression sides respectively. Microscopy and transmission light photography techniques were used to detect the damage behavior and capture the debond zone images. The correlation between the load‐deflection curve, Wohler‐curve, hysteresis loops, dynamic stiffness and debond zones was also examined with regard to different stacked laminates. [ABSTRACT FROM AUTHOR]

This article examines the impact of fatigue cycles on polylactide samples produced by 3D printing using the FDM method. Samples were printed in three infill degree variants: 50%, 75% and 100%. To compere the influence of infill degree on PLA properties, several tests, including the uniaxial tensile test, the low-cycle fatigue test, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), were conducted. Poisson's ratio has also been studied. Single hysteresis loops were summed to obtain the entire low-fatigue cycle. The infill of density influenced all compared mechanical parameters. The decrease in infill degree caused the reduction of Young's modulus and shear modulus. For a 100% degree of sample infill, a higher number of transferred load cycles were observed compared to PLA with 75% and 50% of infill. Additionally, the value of the transferred cyclic load before fatigue failure and the dissipation of mechanical energy was the highest for 100% of infill. It is also worth noting that fatigue tests can positively affect the appearance of the PLA structure. Obviously, it depends on the number of load cycles and the infill density. It causes that if the goal is to transfer as much load as possible over a long period of time, the maximum filling of the printed element should be used. [ABSTRACT FROM AUTHOR]

Using the Monte Carlo method, we have examined in detail the thermal and magnetic properties of a ferrimagnetic mixed-spin (3/2, 5/2) hexagonal Ising nanowire with a core-shell structure. Under the effects of single-ion anisotropy and exchange couplings, we examined different magnetic properties such as partial and total magnetization, susceptibility, specific heat, and phase diagrams. Our particular results show that the system exhibits the second-order phase transitions as well as the compensation points for certain conditions. Moreover, the multiple hysteresis loops with various shapes and step effects have been detected. These important phenomena are compared with previous theoretical and experimental studies. [ABSTRACT FROM AUTHOR]