Hysteretic Effects Research Articles

Robust Static Output Feedback Control of a Semi-Active Vehicle Suspension Based on Magnetorheological Dampers

This paper proposes a novel design method for a magnetorheological (MR) damper-based semi-active suspension system. An improved MR damper model that accurately describes the hysteretic nature and effect of the applied current is presented. Given the unfeasibility of installing sensors for all vehicle states, an MR damper current controller that only considers the suspension deflection and deflection rate is proposed. A linear matrix inequality problem is formulated to design the current controller, with the objective of enhancing ride safety and comfort while guaranteeing vehicle stability and robustness against any road disturbance. A series of experiments demonstrates the enhanced performance of the proposed MR damper model, which exhibits greater accuracy than other state-of-the-art damper models, such as Bingham or bi-viscous. An evaluation of the vehicle behavior under two simulated road scenarios has been conducted to demonstrate the performance of the proposed output feedback MR damper-based semi-active suspension system.

Characterizing the hysteretic effects of water and salinity stresses on root-water-uptake

Characterizing the effects of previous water and salinity stresses is critical for the evaluation of plant water status, which, in turn, is essential for understanding soil-plant water relations and optimizing irrigation schemes. Recent research has found that hysteresis of plant response following water stress alone can be described by an exponential function of the stress degree on the previous day. To explore and quantify the effects of hysteresis concerning salinity stress and combined water-salinity stress, a hydroponic experiment and a soil column experiment on winter wheat, and a field experiment on cotton were conducted. Like water stress, previous salinity stress and combined water-salinity stress also resulted in hysteretic effects on root-water-uptake. Leaf stomatal conductance and plant transpiration rate of stressed crops could only recover gradually from a previous stressed status after re-watering. When stress was mild, compensatory recovery was found, while incomplete recovery occurred when stress was severe. Although the recovery process was closely related to stress history and type, a recovery coefficient was quantified universally with an exponential function of the stress extent on the previous day (with a coefficient of determination R2 ≥ 0.60). Consideration of hysteresis for water and salinity stresses with a mathematical model led to significant improvement in the simulation of both relative transpiration rate (R2 = 0.94, root mean squared error RMSE = 0.04, maximal absolute error MAE = 0.12) and soil water content (R2 = 0.90, RMSE = 0.01 cm3 cm–3, MAE = 0.03 cm3 cm–3), especially during the recovery periods severely affected by historical stress. Consideration of hysteresis is expected to benefit regulation of soil water and salinity and thus enhance water use efficiency. However, the mechanisms underlying hysteresis, especially the compensatory recovery mechanisms, still need to be further investigated.

Effect of compressive stress on piezoelectric coefficients: A multiscale modeling approach

The effect of compressive stress on linearized coefficients for ferroelectric ceramics has been extensively reported experimentally. However, there is no proper model for this effect which could be pertinent to designers of force sensors. This paper introduces a model based on a ferroelectric multiscale model in order to predict the effect of compressive stress on the piezoelectric constitutive laws. The comparison with experimental data shows an excellent qualitative agreement and the use of this model gives new insights on this nonlinear and hysteretic effect.

The effects of meteorological factors and air pollutants on the incidence of tuberculosis in people living with HIV/AIDS in subtropical Guangxi, China.

Previous studies have shown the association between tuberculosis (TB) and meteorological factors/air pollutants. However, little information is available for people living with HIV/AIDS (PLWHA), who are highly susceptible to TB. Data regarding TB cases in PLWHA from 2014 to2020 were collected from the HIV antiviral therapy cohort in Guangxi, China. Meteorological and air pollutants data for the same period were obtained from the China Meteorological Science Data Sharing Service Network and Department of Ecology and Environment of Guangxi. A distribution lag non-linear model (DLNM) was used to evaluate the effects of meteorological factors and air pollutant exposure on the risk of TB in PLWHA. A total of 2087 new or re-active TB cases were collected, which had a significant seasonal and periodic distribution. Compared with the median values, the maximum cumulative relative risk (RR) for TB in PLWHA was 0.663 (95% confidence interval [CI]: 0.507-0.866, lag 4 weeks) for a 5-unit increase in temperature, and 1.478 (95% CI: 1.116-1.957, lag 4 weeks) for a 2-unit increase in precipitation. However, neither wind speed nor PM10 had a significant cumulative lag effect. Extreme analysis demonstrated that the hot effect (RR = 0.638, 95%CI: 0.425-0.958, lag 4 weeks), the rainy effect (RR = 0.285, 95%CI: 0.135-0.599, lag 4 weeks), and the rainless effect (RR = 0.552, 95%CI: 0.322-0.947, lag 4 weeks) reduced the risk of TB. Furthermore, in the CD4(+) T cells < 200 cells/µL subgroup, temperature, precipitation, and PM10 had a significant hysteretic effect on TB incidence, while temperature and precipitation had a significant cumulative lag effect. However, these effects were not observed in the CD4(+) T cells ≥ 200 cells/µL subgroup. For PLWHA in subtropical Guangxi, temperature and precipitation had a significant cumulative effect on TB incidence among PLWHA, while air pollutants had little effect. Moreover, the influence of meteorological factors on the incidence of TB also depends on the immune status of PLWHA.

Magnetism in the axion insulator candidate Eu5In2Sb6

Eu5In2Sb6 is a member of a family of orthorhombic nonsymmorphic rare-earth intermetallics that combines large localized magnetic moments and itinerant exchange with a low carrier density and perpendicular glide planes. This may result in special topological crystalline (wallpaper fermion) or axion insulating phases. Recent studies of Eu5In2Sb6 single crystals have revealed colossal negative magnetoresistance and multiple magnetic phase transitions. Here, we clarify this ordering process using neutron scattering, resonant elastic x-ray scattering, muon spin-rotation, and magnetometry. The nonsymmorphic and multisite character of Eu5In2Sb6 results in coplanar noncollinear magnetic structures with an Ising-like net magnetization along the a axis. A reordering transition, attributable to competing ferro- and antiferromagnetic couplings, manifests as the onset of a second commensurate Fourier component. In the absence of spatially resolved probes, the experimental evidence for this low-temperature state can be interpreted either as an unusual double-q structure or in a phase separation scenario. The net magnetization produces variable anisotropic hysteretic effects which also couple to charge transport. The implied potential for functional domain physics and topological transport suggests that this structural family may be a promising platform to implement concepts of topological antiferromagnetic spintronics. Published by the American Physical Society 2024

Energy-based modeling of rate-independent hysteresis and viscoelastic effects in dielectric elastomer actuators

Dielectric elastomer (DE) transducers are known to exhibit a rate-dependent hysteresis in their force-displacement response, which is commonly attributed to the viscoelastic behavior of elastomer materials and compliant electrodes. In the case of DE materials characterized by low mechanical losses, such as silicone, the mechanical hysteresis often turns out to be practically rate-independent in the low frequency range (sub-Hz), whereas rate-dependent hysteretic effects only become relevant at higher deformation rates. Most of the existing literature focuses on describing DE hysteretic losses using viscoelasticity theory. This approach results in relatively simple dynamic models, which are not capable of describing rate-independent hysteretic behaviors. In this work, we propose a control-oriented modeling framework for both rate-dependent and rate-dependent hysteresis occurring in uniaxially loaded DE actuators. To this end, classic thermodinamically-consistent modeling approaches for DEs are combined with a new energy-based Maxwell-Lion formalization of the hysteretic losses. The resulting dynamic model comprises a set of nonlinear ordinary differential equations, and is capable of simultaneously describe geometric dependencies, large deformation nonlinearities, electro-mechanical coupling, and rate-independent and rate-dependent hysteretic effects. To deal with the large number of involved parameters, a novel systematic identification algorithm based on quadratic programming is also proposed. After presenting the theory, the model is validated based on experiments conducted on a silicone-based rolled DE actuator. Its superiority compared to classic DE viscoelastic models is quantitatively assessed.

Post-earthquake repairability enhancement of BRBFs considering isotropic hardening with self-centering braces

This research's aim is to develop a novel peak and residual deformation-targeted design (PRBD) procedure for enhancing BRBF's post-earthquake repairability with self-centering braces (SCBs). To this end, the peak and residual displacement demands of improved BRBFs (denoted as RBRBFs) were studied by single-degree-of-freedom (SDOF) system analyses, where the isotropic hardening features of BRBs were properly considered. The hysteretic behavior's effects of SCBs on the RBRBF's peak and residual displacements were comprehensively investigated. Artificial neural network (ANN) models were developed for predicting the displacement demands of RBRBFs. Based on the developed ANN model, the PRBD was subsequently proposed. Two design cases were presented based on the developed PRBD method with different design objectives. The designed RBRBFs' performance was investigated via dynamic analyses. It can be found from the results that RBRBFs can achieve the desired peak and residual displacements under design earthquakes, validating the effectiveness of the developed PRBD. Moreover, the excellent post-earthquake repairability of RBRBFs with the partial self-centering feature was confirmed by showing residual displacements lower than 0.2% under maximum considered earthquakes.

Dynamics of a piezoelectric vibration energy harvester with a pseudoelastic SMA spring

The development of small-scale and low power consumption devices has been motivating the design of intelligent mechanisms, exhibiting a wide power density spectrum across various external sources. Smart materials come up as an attractive alternative due to their intrinsic multi-coupling between different physical domains. In this context, piezoelectric materials allow conversion of mechanical energy of movement into electrical power through the direct piezoelectric effect. This work investigates a piezoelectric energy harvester combined with a shape memory alloy (SMA) spring to explore the combination of both the smart materials for energy harvesting. The pseudoelastic hysteretic effect of SMA is explored in order to passively change the internal system properties such as stiffness and damping during the harvesting process. Numerical analyses are performed considering the normalized power converted by the harvester, focusing on the influence of the SMA martensite phase transformation under different scenarios. The results exhibit an increment in the harvester bandwidth when compared with a traditional linear piezoelectric energy harvester.

Layer-polarized ferromagnetism in rhombohedral multilayer graphene

Flat-band systems with strongly correlated electrons can exhibit a variety of phenomena, such as correlated insulating and topological states, unconventional superconductivity, and ferromagnetism. Rhombohedral multilayer graphene has recently emerged as a promising platform for investigating exotic quantum states due to its hosting of topologically protected surface flat bands at low energy, which have a layer-dependent energy dispersion. However, the complex relationship between the surface flat bands and the highly dispersive high-energy bands makes it difficult to study correlated surface states. In this study, we introduce moiré superlattices as a method to isolate the surface flat bands of rhombohedral multilayer graphene. The observed pronounced screening effects in the moiré potential-modulated rhombohedral multilayer graphene indicate that the two surface states are electronically decoupled. The flat bands that are isolated promote correlated surface states in areas that are distant from the charge neutrality points. Notably, we observe tunable layer-polarized ferromagnetism, which is evidenced by a hysteretic anomalous Hall effect. This is achieved by polarizing the surface states with finite displacement fields.

Unveiling heterogeneity of hysteresis in perovskite thin films

The phenomenon of current–voltage hysteresis observed in perovskite-based optoelectronic devices is a critical issue that complicates the accurate assessment of device parameters, thereby impacting performance and applicability. Despite extensive research efforts aimed at deciphering the origins of hysteresis, its underlying causes remain a subject of considerable debate. By employing nanoscale investigations to elucidate the relationship between hysteresis and morphological characteristics, this study offers a detailed exploration of photocurrent–voltage hysteresis at the nanoscale within perovskite optoelectronic devices. Through the meticulous analysis of localized I–V curve arrays, our research identifies two principal hysteresis descriptors, uncovering a predominantly inverted hysteresis pattern in 87% of the locations examined. This pattern is primarily attributed to the energetic barrier encountered at the interface between the probe and the perovskite material. Our findings underscore the pronounced heterogeneity and grain-dependent variability inherent in hysteresis behavior, evidenced by an average Hysteresis Index value of 0.24. The investigation suggests that the localized hysteresis phenomena cannot be exclusively attributed to either photocharge collection processes or organic cation migration at grain boundaries. Instead, it appears significantly influenced by localized surface trap states, which play a pivotal role in modulating electron and hole current dynamics. By identifying the key factors contributing to hysteresis, such as localized surface trap states and their influence on electron and hole current dynamics, our findings pave the way for targeted strategies to mitigate these effects. This includes the development of novel materials and device architectures designed to minimize energy barriers and enhance charge carrier mobility, thereby improving device performance and longevity. This breakthrough in understanding the microscale mechanisms of hysteresis underscores the critical importance of surface/interface defect trap passivation in mitigating hysteretic effects, offering new pathways for enhancing the performance of perovskite solar cells.

Annular impinging jets controlled by synthetic jets inducing a swirling flow character

Experimental research was conducted on an annular air jet. The active flow control was introduced by means of tangentially arranged synthetic jets. Flow visualization and measurements of the flow velocity and stagnation pressure on an impingement wall were performed. Tests were carried out with Reynolds numbers ranging from 4000 to 10,000 (evaluated from the outer exit diameter of the annular nozzle). Bistability and hysteretic effects were revealed, because two alternative flow field patterns (A and B) were identified under the same boundary conditions. In the A pattern, a small recirculation area (bubble) of separated flow was attached to the nozzle centerbody. In the B pattern, a large recirculation area of separated flow bridged the entire nozzle-to-wall distance. The effect of the Reynolds number was evaluated: the hysteresis and bistability were not observed for Re ≥ 9000. Concerning the effect of flow control, it was concluded that a moderate swirling effect can effectively suppress the hysteresis and bistability.Graphical abstract

Revealing temporal variation of baseflow and its underlying causes in the source region of the Yangtze River (China)

Abstract Baseflow plays a crucial role in sustaining the alpine ecosystem during rainless or cold periods. Despite its importance, information on how and why baseflow has changed in the source region of the Yangtze River (SRYR) is sparse. In our study, statistical analysis and the elastic coefficient method were used to identify the dynamic characteristics of baseflow and the underlying causes. The results show that monthly baseflow contributed 62–97% of runoff with a mean value of 75%, and they followed remarkable increasing trends from 1957 to 2020. The contributions of precipitation, temperature, evapotranspiration, and ecological conservation programs (ECPs) on baseflow variations were 86, 53, −15, and −24%, respectively. However, their contributions differed across months. During the warm months of May to September, precipitation played a dominant role, followed by evapotranspiration. In contrast, during other colder months, temperature was dominant; meanwhile, the effect of precipitation was almost absent. Moreover, climatic change had a hysteretic effect on baseflow variation, with a maximum lag time of 10 months. Our results highlighted critical roles of both precipitation and temperature, and indicated that climate change, rather than ECPs, dominated the variation in baseflow in the SRYR.

Giant Magnon-Polaron Anomalies in Spin Seebeck Effect in Double Umbrella-Structured Tb_{3}Fe_{5}O_{12} Films.

We report a giant hysteretic spin Seebeck effect (SSE) anomaly with a sign reversal at magnetic fields much stronger than the coercive field in a (001)-oriented Tb_{3}Fe_{5}O_{12} film. The high-field SSE enhancement reaches 4200% at approximately 105K over its weak-field value and presents a nonmonotonic dependence on temperature. The unexpected high-field hysteresis of SSE is found to be associated with a magnetic transition of double-umbrella spin texture in TbIG. Nearly parallel dispersion curves of magnons and acoustic phonons around this neoteric transition are supported by theoretical calculations, leading to a high density of field-tuned magnon polarons and consequently an extraordinarily large SSE. Our study provides insight into the evolution of magnon dispersions of double-umbrella TbIG and could potentially boost the efficiency of magnon-polarons SSE devices.

Periodic solutions of a population dynamics model with hysteresis

This paper is concerned with a population dynamics model describing the evolution of three biological species. Our system takes into account diffusion and hysteretic effects underlying the evolution process. It is shown that the problem admits a time periodic solution under fairly general assumptions on the hysteresis region and right-hand sides of the system.

Multi-phase FCC-based composite eutectic high entropy alloy with multi-scale microstructure

Multi-phase multi-scale composite eutectic alloys containing micrometer-scale dendrites and nano structures provide an opportunity for the development of ultrahigh strength materials. Eutectic high entropy alloys (EHEAs) facilitate the design of eutectic alloys with such structures in the as-cast state due to the hysteretic diffusion effect characteristic of high entropy alloys. Nevertheless, the prevailing design approach for eutectic high-entropy alloys predominantly emphasizes biphase eutectics, with limited attention directed towards methods for designing multiphase eutectic structures. In this work, we propose a pseudo-ternary based idea to design and prepare multiphase multiscale FCC-based triple-phase eutectic high-entropy alloys, i.e., CoCrFeNi–NiAl-X. Using this strategy, a series of triple-phase EHEAs consisting of face-centered cubic (FCC), ordered body-centered cubic (B2), and Laves phase with topologically-close-packed structure (TCP) were successfully prepared by arc melting, like CoCrFeNi–NiAl–Nb. The four designed FCC-based multi-phase multi-scale EHEAs can be categorized into two main groups: 1) primary phase FCC and biphase or triple-phase eutectic; and 2) primary phase FCC, biphase eutectic and triple-phase eutectic. The designed FCC-based multi-phase multi-scale EHEAs exhibit promising mechanical properties. The design idea is not only applicable to the current work, but also provides a new strategy for the later design of other multi-phase multi-scale composite EHEAs, like CoCrFeNi–NiAl–Ta.

Dynamic behavior analysis of systems with friction and hysteretic effects

This paper investigates the steady-state response of a nonlinear system that incorporates both a hysteretic element and frictional contact under harmonic excitation. While previous studies have separately explored hysteretic oscillators and frictional systems, the simultaneous consideration of both elements has received limited attention. In this study, an analytical solution for the steady-state response is proposed, employing the equivalent linearization approach. This method enables the determination of equivalent stiffness and equivalent damping coefficients for the linearized system, which are directly linked to the amplitude of the steady-state response. To validate the derived analytical solution, a numerical model is utilized, demonstrating the agreement between the analytical and numerical results. Moreover, this paper identifies noteworthy dynamic characteristics of the designed system, notably the occurrence of peak amplitude at excitation frequencies lower than the pre-yield natural frequency. Furthermore, the apex point can be adjusted by manipulating the nonlinear parameters. Building upon these observations, a new mounting system is examined, revealing distinctive behavior.

High-mobility spin-polarized two-dimensional electron gas at the interface of EuTiO3/SrTiO3 heterostructures

Spin polarization of two-dimensional electron gas (2DEG) at the interface of EuTiO3/SrTiO3(STO) heterostructures has been theoretical predicted and experimentally observed via x-ray magnetic circular dichroism and polarized x-ray absorption spectroscopy, which, however, is lack of magnetotransport evidence. Here, we report the fabrication of high-quality EuTiO3/STO heterostructures by depositing antiferromagnetic insulating EuTiO3 thin films onto STO substrates. Shubnikov-de Haas oscillation, Hall, and magnetoresistance (MR) measurements show that the interface is not only highly conducting, with electron mobility up to cm2V−1s−1 at 1.8 K, but also shows low-field hysteretic MR effects. MR of ∼9% is observed at 1.8 K and 20 Oe, which is one order of magnitude higher than those observed in other spin-polarized 2DEG oxide systems. Moreover, the heterostructures show ferromagnetic hysteresis loops. These results demonstrate that the high-mobility 2DEG is spin polarized, whose origin is attributed to the interfacial Ti3+-3d states due to oxygen deficiency and the exchange interactions between interfacial Eu spins and itinerant Ti-3d electrons.

Equations for soil freezing characteristics curves based on the thermodynamics principles

Experimental studies related to the thermo-hydro-mechanical-chemo (THMC) behaviors of unsaturated frozen soils are cumbersome, expensive, and time consuming. For this reason, several researchers suggested mathematical models exploiting the strong relationships between the soil freezing characteristics curve (SFCC) and the THMC behavior of unsaturated frozen soils. However, the physical meanings of parameters in the available models are not clearly defined; hence there are limitations in providing rational interpretation of the frozen unsaturated soils behavior. In the present study, SFCC models with well-defined model parameters are developed extending thermodynamics principles and are linked to well-known soil–water characteristics curves (SWCC) models from the literature. Various zones in the SFCC are discussed along with providing rational explanation for the hysteretic effects using the proposed models. In addition, comparisons are provided between the measured results from experimental studies and the predicted results using the proposed models successfully highlighting the effects of salinity and the initial water content on the frozen unsaturated soils. The SFCC models proposed in this paper are promising and can be used for rigorous interpretation and in the prediction of the complex THMC behaviors of frozen unsaturated soils.

Barocaloric response of plastic crystal 2-methyl-2-nitro-1-propanol across and far from the solid-solid phase transition

Plastic crystals have emerged as benchmark barocaloric (BC) materials for potential solid-state cooling and heating applications due to huge isothermal entropy changes and adiabatic temperature changes driven by pressure. In this work we investigate the BC response of the neopentane derivative 2-methyl-2-nitro-1-propanol (NO2C(CH3)2CH2OH) in a wide temperature range using x-ray diffraction, dilatometry and pressure-dependent differential thermal analysis. Near the ordered-to-plastic transition, we find colossal BC effects of 400 J K−1 kg−1 and 5 K upon pressure changes of 100 MPa. Although reversible effects at the transition are obtained only from higher pressure changes due to hysteretic effects, we do obtain fully reversible BC effects from any pressure change in individual phases, that become giant at moderate pressures due to very large thermal expansion, especially in the plastic phase. From our measurements, we also determine the crystal structure of the low-temperature phase and estimate the contribution of the configurational disorder and the volume change to the total transition entropy change.

Effect of cyclic hysteretic multiphase flow on underground hydrogen storage: A numerical investigation

Hydrogen storage in subsurface geological formation is a complex process requiring information at multiple scales for successful understanding and implementation. While some laboratory investigations and pore-scale studies showed evidence of hydrogen and water cyclic hysteresis, field-scale underground hydrogen storage considering the cyclic hysteretic effect received little or no attention and thus remains poorly understood. This is particularly important due to the fact that an underground hydrogen storage project typically involves repeated cycles of hydrogen injection and withdrawal. In this work, numerical simulations were performed to examine the impact of the cyclic hysteretic effect on the dynamics of hydrogen saturation and the associated efficiency of storage and withdrawal cycles. The results indicate that the cyclic hysteretic effect impedes the injected hydrogen distribution in the formation and results in a greater ultimate hydrogen recovery factor during subsequent withdrawal phases (∼77%). However, the accumulated hydrogen in the formation top will, in turn, increase the formation pressure. The impact of capillary pressure and H2 dissolution in brine were also investigated. The results suggest that capillary pressure and dissolution could alter the hydrogen saturation distribution while depicting a negligible effect on the ultimate hydrogen recovery factor. It was found that the loss of hydrogen due to dissolution can be compensated by avoiding more significant residual trapping in our study.