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The correct description of the kinetics of NH 3 oxidation over Pt is crucial for the optimal catalyst design. Despite a general agreement on the elementary steps, major discrepancies on the value of the activation energy are still present, with experimental studies showing activation energies > 100 kJ/mol, way above the activation energies predicted by DFT (typically around 50 kJ/mol). In this work, we apply a novel kinetic analysis, reconciling experimentally and theoretically derived activation energies. We developed a Transient Response Measurement protocol which allowed to measure the intrinsic kinetics, observing an activation energy of 39 kJ/mol, close to theory, and then the following Pt oxide formation/decomposition. By combining the two phenomena, we obtained a model describing the experimental light-off curves and their high apparent activation energy (>100 kJ/mol). This is explained by the Pt-oxide decomposition evolving concurrently with the heating ramp, leading to a gradual enhancement of the catalytic activity beyond the increase related to the low intrinsic activation energy. Furthermore, our model explains previously observed effects like the NH 3 conversion hysteresis during light-up/light-down, and the O 2 inhibition on NH 3 light-off. The work paves the way for a more fundamental understanding of a wide range of NH 3 conversion/abatement catalytic systems. [Display omitted] • New Transient Response Method shows deactivation due to Pt oxide formation. • Transient Response Method also measures intrinsic rate on oxide free Pt catalyst. • Low intrinsic action energy on oxide free surface in agreement with DFT. • Higher activation energy in light-off curves explained by concurrent oxide formation. • NH 3 conversion hysteresis and the O 2 inhibition explained by Pt oxide formation. [ABSTRACT FROM AUTHOR]

• Transient heat pipe model to predict the response to pulse-load-induced dryout. • Model considers spatiotemporal variations in local liquid saturation in the wick. • Experiments are performed using commercial heat pipe samples to validate the model. • Validation spans a range of wick types, heat pipe lengths, and heat pipe thicknesses. • Model accurately predicts thermal hysteresis, dryout, and recovery from dryout. Heat pipes are capillary-pumped two-phase devices that transport heat from localized sources in electronics to a heat sink through continuous evaporation and condensation of an internal working fluid. Given the reliance of a heat pipe on capillary transport of liquid through internal wicking structures to the evaporator section where heat is applied, operating it at a power exceeding the so-called capillary limit can lead to dryout at the evaporator and subsequent device failure. However, in response to highly dynamic workloads in the electronics being cooled, heat pipes may more typically be exposed to heat loads above the capillary limit only intermittently over brief time intervals. Understanding the heat pipe response to these transient workloads is critical, as designing heat pipes for steady-state operation at the peak transient heat load would represent an expensive overdesign. Our previous work has experimentally characterized the transient heat pipe response to power pulses exceeding the capillary limit. It was demonstrated that a pulse must be sustained for a minimum duration termed the time-to-dryout before dryout is initiated. Once a pulse-induced transient dryout does occur in a heat pipe, its thermal resistance does not necessarily recover back to the pre-dryout performance even after the power input drops below the capillary limit. This behavior, termed thermal hysteresis, can be circumvented if the power is lowered (or throttled) to a sufficient threshold below the capillary limit for an extended time interval. In the current work, a first-of-its-kind transient heat pipe model is developed to predict the salient features of heat pipe response to pulse-load-induced dryout as well as recovery from dryout. The model uniquely considers spatiotemporal variations in local liquid saturation in the wick (i.e., the fraction of pore volume occupied by the liquid). Experiments are performed using commercial heat pipe samples that span a range of sizes and wick types to validate the model predictions. It is shown that the model can predict the transient thermal response, including thermal hysteresis, of the heat pipe during pre-dryout, dryout (pulse load), and post-dryout (recovery) stages with good accuracy. The model results are also validated against experiments for heat pipes spanning a range of wick types, heat pipe lengths, and heat pipe thicknesses. The capability to accurately predict crucial temporal events during dryout and recovery is key to establishing power expenditure strategies in electronics and designing heat pipes with improved dryout and recovery performance. [ABSTRACT FROM AUTHOR]

• High performance IATO films and TFTs are prepared by RF magnetron sputtering. • The IATO films have high transparency and wide band gap. • The 50 W-fabricated IATO TFTs possess the best overall performance. • The IATO TFTs exhibit good bias and illumination stability. The amorphous In-Al-Sn-O (IATO) is a very promising material fulfilling the increasing demands of thin film transistors (TFTs). Here, high performance IATO films and TFTs were prepared using RF magnetron sputtering with the sputtering power (20–200 W) being systematically investigated and optimized for the first time. All IATO films exhibited an amorphous structure, dense and flat surfaces, high average absolute visible transmittances (95.0 to 96.6%), and large optical band gaps (4.18 to 4.44 eV). The TFTs fabricated at 50 W demonstrated the best overall performance including the highest saturation mobility (10.71 ± 1.79 cm2 V-1 s-1) and on-off current ratio (11.89 ± 4.33 × 108), as well as the lowest subthreshold swing (0.30 ± 0.07 V dec-1) and hysteresis (0.11 ± 0.50 V) values. Meanwhile, the 50 W-fabricated IATO TFTs also showed high stability under the gate bias and illumination stresses, further indicating the promising application prospects of our IATO TFTs. [Display omitted] [ABSTRACT FROM AUTHOR]

The physiological state of functional leaves in crops plays a vital role in yield formation. Over two consecutive winter wheat growing seasons, we continuously monitored the flag leaf temperature (Tf) during the reproductive growth stage and collected key meteorological indicators, including air temperature (Ta), relative humidity (Ha), soil temperature (Ts), and photosynthetically active radiation (PAR). Pearson correlation analysis, stepwise regression analysis, and path analysis revealed that Ta, PAR, Ts, and Ha are the main environmental factors influencing Tf. These variables were identified as key for further analysis. Notably, Tf exhibited a positive time lag correlation with PAR, while Ta and Ts lag showed positive lag correlation with Tf, and Ha demonstrated a negative lag correlation with Tf. Among the analyzed meteorological factors, soil temperature displayed the smallest lag effect relative to Tf, consistently trailing behind it. PAR showed a pronounced lag effect, shifting an hour earlier than Tf, while Ta exhibited a significant hour-long delay after Tf. Ha primarily functioned as a cooling influence, lagging approximately one hour behind Tf. Moreover, the intensity of the time delay effect will vary depending on the developmental stage. Integrating these time-lag relationships significantly enhanced the accuracy of Tf simulations. Support Vector Regression (SVR) demonstrated robust predictive performance (R2 = 0.937, RMSE = 2.048 °C), indicating its potential for accurate prediction of Tf in wheat production. This study highlights the time-delay effects between Tf and meteorological factors during the reproductive growth stage of wheat, offering a predictive model that provides a foundation for monitoring crop physiological conditions in real time. [ABSTRACT FROM AUTHOR]

Hysteresis in the relation between the capillary pressure and the moisture content in unsaturated porous media, which is due to surface tension at the liquid-gas interface, exhibits strong degeneracy in the resulting mass balance equation. Solutions to such degenerate equations have been recently constructed by the method of convexification. We show here that the convexification argument works even if the permeability coefficient depends on the hysteretic saturation. The problem of uniqueness remains open in this case. [ABSTRACT FROM AUTHOR]

This study investigates the influence of capacitance on the non-zero crossing hysteresis observed in Ag/CoWO 4 /FTO devices. This work successfully synthesized uniform and adherent cobalt tungstate (CoWO 4) film using spray pyrolysis at 350 ℃. The results revealed a pure, monoclinic polycrystalline phase with a crystallite size of ∼50 nm. The electrical properties demonstrated that a typical capacitive behavior characterizes current-voltage (I-V) hysteresis. The non-pinched hysteresis curve is observed from ±0.5 V to ±3 V, while the non-zero crossing hysteresis curve is obtained at ±4 V and ±5 V. The device demonstrates low power consumption, ranging from 0.3 nW to 310 nW across the tested voltage range. Reliability studies show minimal cycle-to-cycle variation (coefficient of variance <10 %) in SET and RESET currents, except at ±5 V. A higher Weibull β indicates more stable and uniform resistive switching. The β values for SET and RESET currents range from 10.06 to 58.06, excluding 146 at +3 V. Further, the fabricated device showed stable performance over 103 switching cycles without degradation. The Ag/CoWO 4 /FTO device exhibits double-valued charge-flux characteristics, suggesting it is a non-ideal memristor. The results suggest uniformity and reliability during the RS process. This work gives new insight into developing the metal tungstates-based memristive device based on the capacitive effect for non-volatile memory application. [Display omitted] • Cobalt Tungstate (CoWO 4) thin film was successfully synthesized using spray pyrolysis. • Non-pinched and non-zero crossing hysteresis curves were observed due to capacitive coupling. • Statistical analysis suggests good stability and reliability of fabricated devices. • The device can switch the data up to 103 cycles. • The findings provide valuable insights into the development of metal tungstate-based memristive devices for non-volatile memory applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Polyelectrolytes have shown promise as sensitive material for high-performance humidity sensors in recent years. How to obtain fast recovery and high sensitivity polyelectrolyte humidity sensors is a great challenge. A kind of poly(ionic liquid)s (PILs) humidity sensors modified by zwitterionic polymers (partially zwitterionic PILs, named PZPILs) were prepared in this work. The PZPILs can transform between PILs and zwitterionic polymers in different humidity sensitive processes. In the adsorption process of water molecules, characteristics of PZPILs are similar to those of PILs. When desorbing water molecules, the characteristics of PZPILs trend to those of sulfobetaine (SB) type zwitterionic polymers. This design endowed the humidity sensors high response and fast response/recovery characteristics. The optimized PZPILs sensor shows high response (4862.8) in a wide relative humidity (RH) range of 11 %–95 %, with short response/recovery time (1.0 s/15.0 s) and small humidity hysteresis about 0.6 % RH. The PZPILs shortened the recovery time of the PILs humidity sensors (from 143.4 s to 15.0 s), and improved the response (from 1980.8 to 4862.8). [ABSTRACT FROM AUTHOR]

The excellent strain behavior of piezoelectric stack actuators (PSAs) is critical for expanding their applications in precision control fields. Traditional PSAs are constrained by the limitations of piezoceramics, such as low piezoelectric coefficients and high dielectric loss. This study employs piezoelectric single crystals from two systems, Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PMNT) and Pb(In 1/2 Nb 1/2)O 3 -Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PIMNT), to fabricate 15-layer PSAs (6 × 6 × 6.7 mm3) and analyze their strain behavior. Under 25 °C, 1 Hz, and 1.0 kV/mm, the PMNT- and PIMNT-based PSAs achieved maximum strains of 1.63 ‰ and 1.33 ‰, respectively, with hysteresis values of 3.54 % and 3.27 %. As the electric field increased from 1.0 to 1.5 kV/mm, the maximum strain of both PSAs increased linearly, while hysteresis remained stable. However, when temperature rose from 25 °C to 115 °C, the PMNT-based PSA exhibited a relatively greater growth rate than the PIMNT-based PSA in both strain and hysteresis. Under the preloading force of 360 N, the PMNT- and PIMNT-based PSAs exhibit the blocking force of 433 N and 386 N. Overall, the PMNT-based PSA excels in high-strain output, and the PIMNT-based PSA offers thermal stability. [Display omitted] • This work provides comprehensive strain parameters for PSAs based on single crystals, including maximum strain, hysteresis, effective piezoelectric coefficient, stability, and blocking force. • A systematic comparison between PSAs based on PMNT and PIMNT single crystals is presented. The advantages and disadvantages of the two types of PSAs are summarized. • Compared to traditional piezoceramic-based PSAs, the fabricated PSAs demonstrate low hysteresis, which reduces the dependence on feed-forward compensation mechanisms. • This study also provides the fundamental electrical parameters of the single crystals and outlines the actuator fabrication process, offering valuable insights for future research. [ABSTRACT FROM AUTHOR]

In rubber nanocomposites, filler networks gradually form during post-mixing stages, a topic of considerable interest in the field. However, the exact mechanisms underlying filler structure formation remain unclear due to complex processing conditions and filler-rubber interactions, posing a major challenge for optimizing composite performance. Herein, we demonstrate to track the evolution of filler structures in silica-filled rubber composites during storage stage, capturing gradual changes using various imaging and analytical techniques. As storage time prolongs, silica aggregates gradually re-agglomerate, developing into interconnected and percolating filler networks within 2 days, followed by occurrence of extensive micron-sized filler flocs with further storage. Filler-rubber interactions strengthen with extended storage time, mutually affecting filler flocculation. Additionally, the tensile fatigue lifetime of vulcanized rubber composites improves by 67 % after 2 days of storage, but gradually declines as storage extends to 7 days. The abrasion resistance of composites improves by 10 % after 4 days of storage, but reverts to the initial level observed in the composite without storage. These changes in dynamical properties derive from the interplay between enhanced interfacial interactions and the evolving state of filler structures. Besides, hysteresis loss reduces in rubber composites undergoing the early storage period, then rises significantly with prolonged storage. This can be attributed to the combined effects of occluded rubber formation and the friction and rearrangement of rubber and filler flocs on energy dissipation. This study offers crucial insights into understanding filler structure evolution and structure-property relationships within composites, advancing the development of high-performance polymer composites. [Display omitted] • Filler aggregates form dendritic flocs, creating networks with occluded rubber. • Adsorbed and occluded rubber in the flocs drive the rise in bound rubber early on. • As Filler flocs grow, flocculation slows, and bound rubber increase also decreases. • Composites properties are tied to filler structures evolved over storage periods. [ABSTRACT FROM AUTHOR]

• Theory of the hysteresis with the applied stress is developed. • The constitutive model of magneto-mechanical coupling is proposed. • An extended analysis of the working conditions is performed. • Effects of tensile stress, magnetic intensity, and material types are clarified. • Influences of initial magnetization and cyclic load-unload are analyzed. The initial magnetization state, magnetization history, stress loading history, and material type of ferromagnetic materials have significant effects on the self-magnetic flux leakage (SMFL) stress detection, which therefore needs to be clarified, and the key to clarifying these effects is to establish the magneto-mechanical coupling constitutive model accurately. Thus, mathematical descriptions of magneto-mechanical coupling are constructed, by combining the basic magnetization characteristics and hysteresis properties of ferromagnetic materials. The accuracy and validity of such fundamental theories are verified by experimental examples, allowing for an extended analysis of the working conditions. The results show that the proposed model is well suited to complex cross-coupling conditions of applied magnetic field H (involving constant excitation magnetic intensity H 0) and tensile stress σ t (involving cyclic loading and unloading), predicting the stress-induced magnetization behaviour and its variation law in ferromagnetic materials effectively. The study here can further serve as an important theoretical basis for the work on numerical analog analysis, guiding the quantitative analysis of SMFL stress detection of ferromagnetic materials on the theoretical level. [ABSTRACT FROM AUTHOR]

In this study, a novel method is proposed to recover the close-loop hysteresis curve from measurements with lift-offs which is achieved by Jiles–Atherton (J–A) hysteresis model and offers an alternative to the existing empirical methods. An experiment measurement system is developed to obtain the hysteresis curves under different lift-offs first, and then the J–A hysteresis parameters are derived by inversion method. Using the trends in these parameters and by extrapolation, close-loop hysteresis parameters and curves are predicted and recovered. Good agreement with experimental data is found, demonstrating the validity of the proposed recovery method with the error of 0.26% and 2.49% for the coercivity and remanence value between the measurement curve and recovered close-loop hysteresis curve. This method has potential to extend the technique to in field measurement where lift-off is inevitable due to access needs or non-contact requirements such as in online production. • A novel method is proposed for recovering the closed-loop hysteresis curve from measurements affected by lift-offs. • An experiment measurement system is developed to obtain the measurement curves. • The recovered hysteresis curves show good agreement with experimental data, with an error of less than 3% between the measured and recovered closed-loop hysteresis curves. [ABSTRACT FROM AUTHOR]

The importance of continuous and reliable pulse wave monitoring is constantly being increased in health signal monitoring and disease diagnoses. Flexible pressure sensors with high sensitivity, low hysteresis and fast response time are an effective means for monitoring pulses. Herein, a special wave-shaped layered porous structure of carbonized wood cellulose sponge (CWCS) was constructed based on natural wood (NW). Thermoplastic polyurethane (TPU)/CWCS (PCWCS) composite flexible pressure sensitive elements were formed by immersing a TPU solution into the CWCS skeleton. The PCWCS-4 % based sensors exhibited high sensitivity of 164.77 kPa−1 (0.01–0.5 kPa), low hysteresis (0.70 %), short response time (21 ms), low detection limit and good cycling stability. The exceptional sensing performance was attributed to the wave-shaped layered porous structure of the PCWCS, which rapidly established conductive pathways and reduced stress concentrations during compression. Due to the high sensitivity and low hysteresis of sensors, more comprehensive pulse and other physiological signals could be obtained. Therefore, the PCWCS flexible pressure sensor possesses great potential for application in smart wearable and healthcare. • The high-performance flexible pressure sensor with extremely low hysteresis and excellent sensitivity is prepared. • The excellent sensing properties, such as fast response time, low detection limit, and good cycling stability are displayed. • The effect of unique wave-shaped layered porous structure on sensor demonstrated by finite element simulations. • The prepared sensors have the ability to accurately monitor dynamic pulses. [ABSTRACT FROM AUTHOR]

We report the regeneration of truncated Airy pulses using the asymmetric inversion phenomenon obtained exclusively with the interaction between the third-order dispersion (TOD) and the fourth-order dispersion (FOD). Such regeneration shows a succession of alternating hysteresis cycle shapes (HCSs) and reversed HCSs. The weakness of the dispersion of the medium makes it possible, compared to other pre-existing regeneration techniques, to obtain significantly greater maximum signal intensities in the focal area (FA) regions. Starting with an asymmetric inversion phenomenon in anomalous FOD is found to be the best method unlike the case of starting in normal FOD which achieves the worst case of regeneration in agreement with the results obtained in other techniques. Increasing the nonlinearity is deleterious for the regeneration so for more realistic conditions, it is rather required to operate with a weakly nonlinear transmission line at low value of the anomalous FOD. • Regeneration of the Airy pulse using the third-order dispersion (TOD) and the fourth-order dispersion (FOD). • The weakness of the dispersion compared to other techniques induces significant maximum intensities during propagation. • This regeneration is better when using the anomalous FOD at the start of propagation with a strong positive TOD. • The strong Kerr nonlinearity is deleterious for this regeneration. • Optimally and efficiently achieving such regeneration requires low anomalous FOD and low nonlinearity. [ABSTRACT FROM AUTHOR]

Fixed-point or Newton-methods are typically employed for the numerical solution of nonlinear systems arising from discretization of nonlinear magnetic field problems. We here discuss an alternative strategy which uses Quasi-Newton updates locally, at every material point, to construct appropriate linearizations of the material behavior during the nonlinear iteration. The resulting scheme shows similar fast convergence as the Newton-method but, like the fixed-point methods, does not require derivative information of the underlying material law. As a consequence, the method can be used for the efficient solution of models with hysteresis which involve nonsmooth material behavior. The implementation of the proposed scheme can be realized in standard finite-element codes in parallel to the fixed-point and the Newton method. A full convergence analysis of all three methods is established proving global mesh-independent convergence. The theoretical results and the performance of the nonlinear iterative schemes are evaluated by computational tests for a typical benchmark problem. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) represent a promising solution for thermal energy storage (TES) since they can store and release energy in the form of latent heat during solid ↔ liquid transitions. Nevertheless, accurately simulating the thermal behavior of PCMs remains challenging due to the non-linearities concerning latent heat effects and enthalpy hysteresis. This work introduces a stable and robust procedure based on the finite element method (FEM) under a mixed enthalpy–temperature formulation to address such non-linearities, which enables the numerical solutions using derivative-based algorithms such as the Newton–Raphson (NR) method. The static hysteresis model (SHM) is implemented in the FEM-based formulation via a regularization of the liquid fraction function in response to the sign of the temperature rate. This novel approach ensures a continuous and smooth heating ↔ cooling transition while retaining the SHM energy-conservative features to properly solve its non-linearities. The method is validated through a one-dimensional benchmark problem, demonstrating high performance and physical fidelity for both complete and partial phase changes. It achieves second-order convergence rates, ensures numerical stability even for large time steps, and maintains accuracy under diverse thermal boundary conditions. Finally, the method is extended to two-dimensional problems, highlighting its robustness and scalability for practical applications in TES systems. [ABSTRACT FROM AUTHOR]

• This paper's main innovation is that it combines the hysteretic heat inside the sealing ring, the frictional heat in the sealing contact area, and the influence of thermal effects on the material constitutive model to establish reciprocating seal Soft elastohydrodynamic lubrication considering structural thermal. • The elastic deformation, surface roughness and fluid cavitation effects of seals are synthesized. The elastic half-space theory is adopted to calculate the microelastic deformation of the seal element, which effectively avoids the inefficiency of calculating the influence coefficient matrix in the traditional soft-elastichydrodynmic lubrication modeling process. • The model is verified by an independently designed reciprocating sealing test rig to show that it is more accurate than traditional models. The reliability of the reciprocating seal is the key to ensuring the regular operation of the entire hydraulic system. Since friction in the sealing area under reciprocating conditions and the hysteresis heat inside the seal ring can cause significant temperature rise, which leads to changes in the contact pressure distribution of the seal and the material's constitutive model, previous studies have not considered this thermal effect and its impact. The study combines the effects of hysteresis heat generation, friction heat generation, and thermal effects on the constitutive model of the sealing material to establish a structural thermal coupling reciprocating seal soft elastohydrodynamic lubrication. The comparative analysis discusses the sealing characteristics of the conventional uncoupled model and the Y-shaped sealing ring of this model under different environmental conditions, and a reciprocating sealing test bench is also built for verification. The results show that under a medium working pressure of 3-11 MPa and a reciprocating speed of 0.05-0.3 m/s, the average error between the model considering thermal effects and the experimental value is 5%. In contrast, the conventional without coupled model is 13%. Therefore, the model in this paper predicts more accurately than the traditional model. [ABSTRACT FROM AUTHOR]

A novel parallel double-stage yield buckling restrained brace (PDY-BRB) is introduced within this investigation. The proposed BRB is characterized by unique detailing that facilitates rapid assembly and reliable mechanical performance while exhibiting substantial adaptability in load resistance, deformability, and energy dissipation capacity to accommodate diverse design criteria. A critical evaluation of high-performance materials is initially undertaken. Subsequently, a detailed configuration of the PDY-BRB and hysteretic behavior is presented. The cyclic performance of the PDY-BRB is subsequently investigated through finite element analysis, encompassing hysteretic response, energy dissipation capacity, re-centering capability, and mechanical indexes. A comprehensive parametric study is then conducted to assess the influence of geometrical characteristics on the cyclic behavior of the PDY-BRB, leading to the development of an improved PDY-BRB (IPDY-BRB). The research is extended to a system-level analysis to evaluate PDY-BRB's and IPDY-BRB's efficacy in seismic control. Findings indicate that the rational design of the PDY-BRB effectively mitigates the structure's peak and residual inter-story drift ratio. A salient advantage of the proposed BRBs over conventional BRBs is their superior control of residual story drift ratios. • A novel parallel double-stage yield buckling-restrained brace was introduced. • A trilinear kinematic hysteresis model was presented for PDY-BRB. • Partially self-centering capability of PDY-BRBs was observed. • PDY-BRB with an optimal geometric specification cores were determined. • The impact of PDY-BRB on overall structural response is analyzed. [ABSTRACT FROM AUTHOR]

An innovative partial self-centering coupled shear link (SC-CSL) has been developed for use between a steel brace and a brace connection plate in the concentrically braced frame (CBF). The SC-CSL integrates a coupled very short shear link (C-VSSL), four shape memory alloy (SMA) bars, and four stacks of disc springs, resulting in low residual deformation and high deformability. Consequently, the seismic resilience of the CBF is significantly improved. The hysteresis performance and failure modes of the C-VSSL and SC-CSL were designed and analyzed using a validated finite element (FE) method. Subsequently, the seismic performances of CBFs equipped with a steel brace, C-VSSL, and SC-CSL were investigated. The results show that the average overstrength factor of the C-VSSL reached 3.58, with the error between theoretical calculations and FE results being less than 8 %. The SC-CSL demonstrated excellent bearing capacity and self-centering capability with minimal residual deformation. When the CBF is under tension, the SMA bars mainly sustain tension, while the disc springs remain stationary. When the CBF is under compression, the disc springs mainly sustain compression, while the SMA remains stationary. Stiffness degradation was observed in CBFs with steel braces (CBF-SB) due to the buckling of the steel brace under compression, but no degradation was noted for CBFs with C-VSSL (CBF-C-VSSL) or SC-CSL (CBF-SC-CSL) during rare earthquakes. Furthermore, the residual deformation of the CBF-SC-CSL significantly decreased during rare earthquakes, indicating superior seismic performance and resilience. • An innovative self-centering coupled shear link equipped in CBF was developed. • A calculating model for overstrength factor of coupled very short shear link was proposed. • The partial self-centering coupled shear link showed excellent bearing capacity and self-centering. • CBFs with self-centering coupled shear link presented superior seismic performance. [ABSTRACT FROM AUTHOR]

Buckling-restrained rods (BRRs) can serve as the structure fuse to mitigate seismic damage. To enhance the bearing capacity of BRRs and facilitate installation, a multi-core buckling-restrained rod (MBRR) with symmetrical layout features was proposed. In this paper, cyclic loading tests with ten BRR specimens were conducted, including single-core BRRs (SBRRs) with square casing, round-casing SBRRs, and MBRRs. The test results revealed that square-casing SBRRs exhibited tension-compression symmetric behavior and energy dissipation capability comparable to those of round-casing SBRRs. Employing a square steel tube that is more easily assembled to restrain the core is feasible. Both SBRRs and MBRRs exhibit stable hysteretic behavior, with dispersion ratios of performance indices for individual specimens and the dispersion ratios of performance indices among specimens satisfying the requirements of FEMA 356. The global buckling of the MBRR caused by the bending of the connection plate can significantly reduce the compressive capacity and energy dissipation capability. To avoid this failure mode, an analytical model for global buckling was established, and a method for calculating the critical load P cr was proposed. • Investigating a new multi-core buckling-restrained rod (MBRR) energy dissipater with square casing. • Evaluating the effect of the shape of the casing and the number of cores on the hysteretic performance of BRRs. • Developing a method for calculating the critical load P cr for the global buckling. [ABSTRACT FROM AUTHOR]

Traditional dampers possess energy dissipation capabilities but generally lack self-centering abilities, leading to significant residual deformations in structures after earthquakes. In this study, a novel damper that integrates ring springs with grooved plates was developed, termed the ring spring-based self-centering friction damper (RS-SCFD). First, the basic structure and working principle of the RS-SCFD were described, and its theoretical hysteresis model was analyzed. Subsequently, four specimens were designed to experimentally investigate the hysteretic behavior of the RS-SCFD, and the effectiveness of the theoretical analysis was verified with experimental results. Finally, the operational performance of the novel beam-column joint with the RS-SCFD was demonstrated by experiment and finite element analysis (FEA). The study demonstrated that the RS-SCFD exhibits a full, flag-shaped hysteresis loop in both tension and compression, indicative of its good self-centering and energy dissipation capabilities. Experimental results showed that increasing the preload force on the ring-spring bolt assemblies significantly enhanced the RS-SCFD's energy dissipation and self-centering capabilities, while reducing the number of ring-spring bolt assemblies decreased the damper's load-bearing capacity. The specimen without grease on the contact surface between the core and cover plates showed an increase in energy-dissipation capacity, but its self-centering capability was weakened. The application test indicated that beam-column joints with the RS-SCFD exhibit good self-centering and energy dissipation capabilities. When the drift ratio of the joint reaches 4 %, damage is concentrated in the replaceable ring springs, while core components such as beams and columns remain undamaged. This proves that the application of RS-SCFD can effectively ensure joint safety during earthquakes. • A novel ring spring-based self-centering friction damper (RS-SCFD) is developed. • A theoretical hysteresis model of the RS-SCFD is established. • An experimental investigation for the cyclic behavior of the RS-SCFD is conducted. • The force characteristics of a novel beam-column joint with the RS-SCFD were analyzed and the joints exhibiting excellent mechanical properties. [ABSTRACT FROM AUTHOR]

This study presents the mathematical characterization of the recently developed pressurized sand damper (PSD) in which a steel sphere or bolt is moving within a cylindrical tube filled with sand under pressure. The experimental results, presented in previous studies, revealed that the force output exhibited by the PSDs is stable, symmetric, and nearly velocity-independent. Thus, the PSDs are response-modification devices that offer rate-independent dissipation. In addition, when tested at various levels of pressure, displacement amplitude, and frequency, the PSD displays hysteresis loops with pronounced pinching. To accurately reproduce their response, a recently formulated phenomenological model [the Vaiana Rosati model (VRM)] is employed. The VRM allows for the evaluation of the output variable by means of analytical closed form expressions or equivalent rate equations; in addition, it captures, with good accuracy, the experimental responses of the PSDs obtained for both periodic and nonperiodic displacement time-histories. Practical Applications: When natural hazards such as strong earthquakes, high winds, and wave actions occur, they impose extreme dynamic loads on our civil structures and to structural systems that exhibit inelastic behavior. In an effort to explain the behavior of such systems when subjected to these cyclic loads, load-displacement curves are plotted. The enclosed area of each loop reveals the dissipated energy over a full cycle of loading–unloading, which is referred to as hysteresis. In lay terms, the hysteresis can be considered as the memory of an inelastic system, since the restoring force depends not only on the current value of each moment, i.e., on the current deformation but also on the past history of the input motion; thus, a number of state variables need to be known. The dynamic characteristics of nonlinear hysteretic systems that can dissipate large amounts of energy can accurately be predicted with the study of their hysteresis loop. The characterization of inelastic systems that can dissipate energy and generate large hysteresis loops is achieved with phenomenological models. In this study, a newly developed phenomenological model that allows for the evaluation of the output variable by means of analytical closed form expressions or equivalent rate equations is used to simulate the typical pinched hysteresis loops characterizing the rate-independent behavior of pressurized sand dampers. [ABSTRACT FROM AUTHOR]

This paper presents experimental and theoretical research aimed at deepening the understanding of the lateral response of monopiles in sand subjected to cyclic loading. A series of 1-g model tests were performed for varying cyclic load and magnitude ratios, as well as for different pile stiffnesses. The broadly phenomenological behaviors of the monopile including accumulated displacement, cyclic secant stiffness, bending moment and reloading responses were captured. The results reveal the effects of cyclic load ratio, amplitude ratio and pile stiffness on the development of accumulated displacement and secant stiffness, and point out the action mechanism that the cyclic bending moment of rigid piles tends to increase while that of flexible piles tends to decrease. The elastic threshold of the reloading curve gradually increases with cycling, and increases with the increment of cyclic magnitude ratio. Crucially, a generalized model capable of describing the hysteretic characteristics of loading curves of monopiles was established, and the computational formulas for predicting the peak accumulated and residual displacements were derived. The reasonableness of the proposed method was verified under different loading parameters and pile-soil systems, which could be used for the preliminary design of offshore monopiles. • (1)The effect of pile stiffness on the development of accumulated displacement and secant stiffness is clarified. • The relationship between cyclic pile bending moment and relative pile-soil stiffness is explored. • Hysteresis characteristics of reloading curves under different cyclic loading histories are investigated. • A new method for predicting peak accumulated and residual displacements of monopiles is proposed. [ABSTRACT FROM AUTHOR]

The mechanical properties of slidable cross-links mediated dual cross-linked polymers present an improvement over those of standard single cross-linked polymers. Nonetheless, the specific role played by the two cross-links within the same condensed polymer state remains ambiguous, and the distinct characteristics and interconnected impacts of these two cross-links necessitate further investigation. The introduction of different cross-links can result in polymers displaying wholly disparate mechanical behaviors. In this study, a constitutive model is developed by integrating self-avoiding walk and scaling theory to examine the rubber elastic behavior of dual cross-linked polymers undergoing slidable cross-links mediation. Following the principles of rubber elasticity, the mechanism underlying the formation of dual cross-linked polymers is elucidated, encompassing stable cross-linked networks, slidable cross-linked networks, and their coupling effects, which correspond to molecular mechanisms, such as the Gent model, self-avoiding walk chains, and scaling theory, respectively. Moreover, based on the Kardar-Parisi-Zhang scaling, the stable cross-linked network entails boundary conditions, while the sliding chain experiences constrained self-avoiding walking to relax stress and dissipate energy. The study further offers insights into the free energy of slidable cross-links mediated dual cross-linked polymers to analyze their rubber elasticity and hysteresis (loading-unloading cycle) effects. Finally, the efficacy of the proposed constitutive models is affirmed through comparison with experimental results documented in the literature, shedding light on the exceptional mechanical properties of dual cross-linked polymers. [ABSTRACT FROM AUTHOR]

• A hysteresis model is developed to accurately describe the time-varying nonlinear actuation behavior of twisted and coiled tube actuators. • Increasing anisotropy can significantly improve the actuation performance of tube actuators, while performance decreases with higher pressurization rates and load. • Geometric parameters can optimize the load capacity and actuation performance of tube actuators, providing insights for their structural optimization and actuation control. The twisted and coiled actuators (TCPAs) are new soft actuators that outperform biological muscles on many metrics. Many actuation models have been derived for the control and implementation of the TCPAs, but it is still difficult to accurately describe the hysteresis characteristics. Here, we perform actuation tests on the twisted and coiled tube actuators driven by hydraulic pressure. Based on the generalized Maxwell model, we develop an actuation model for the tube actuators using the updated Lagrangian description. The model can accurately characterize the time-varying nonlinear responses of the actuators. The results indicate that the actuation performance gradually decreases with the pressurization rate and load. An increase in anisotropy can significantly improve the actuation performance. The bias angle of the intermediate layer can determine the twist number of the precursor tube. The load capacity and actuation performance of the tube actuators can be controlled by helix angle and helix radius. This work guides the structural optimization design and precise actuation control of the polymer tube actuators. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel constitutive model is proposed to reproduce nonlinear elasticity and dry friction of metal-rubber isolator. • A constrained identification is developed to determine model parameters of hysteretic behavior. • A stick-slip state of internal metal wires is equivalently distinguished. • An isolator system is numerically simulated to validate the proposed model, as well as the experimental investigation. Metal-rubber isolators (MRIs) have been widely used to mitigate vibration in sensitive equipment due to their high damping properties. This paper aims to predict the nonlinear vibration response of an MRI system by using the hysteretic nonlinearity of a single MRI. An experimental study was conducted to investigate the effects of excitation levels on the hysteretic nonlinearities of a typical MRI. An asymmetric hysteresis model (AHM) was developed to accurately reproduce the experimental hysteresis loop by simultaneously considering the nonlinear elasticity and dry friction damping. The equivalent slip force amplitude of the MRI can be extracted from the frictional damping force to describe the slip state of the internal metal wires. Additionally, it was integrated as a constraint into parameter evolution to accurately predict the hysteretic behavior at various excitation amplitudes. The harmonic balance method (HBM) combined with alternating frequency-time (AFT) analysis was used to simulate the steady-state nonlinear vibration response of a complex MRI system. The simulation results showed good agreement with the experimental data, and indicated two major nonlinear phenomena: nonlinear softening stiffness and nonlinear damping effects. This paper developed a modeling and simulation strategy spanning from the MRI element to the system level. [ABSTRACT FROM AUTHOR]

• Intentionally cracked REBCO split wires were fabricated using V-bending and pressure concentration methods. • We obtained a high critical current that is higher than that of original single core coated conductor by about 15 %. • The AC-loss of the split wire can be reduced to 3 % of original single core coated conductor. • The fabrication method and conditions of split wire have a large effect on its critical current and AC-loss. Tape shape of REBCO-coated conductor with a single-core structure is commercially available. However, the single core leads to a large AC-loss due to magnetization hysteresis. A multi-core structure can be used to reduce this loss. However, it is difficult to fabricate a long multi-core wire made of a REBCO-coated conductor because defects generated during the fabrication process lead to local decreases in the critical current. To obtain a large critical current throughout the wire, the critical current in each core should be maintained. However, local defects in most cores in a long wire reduce the critical current. This study proposes an intentionally cracked REBCO split wire that has a multi-core structure but without complete separation of the cores. [ABSTRACT FROM AUTHOR]

Seismic isolation technology typically protects superstructures by incorporating isolation bearings between the superstructure and the foundation. The isolation system extends the natural period of the structure and provides additional damping, effectively dissipating earthquake-induced energy during strong earthquakes. Among the commonly used bearings, high-damping rubber bearings (HDRBs) have emerged as a preferred solution due to the inherent energy dissipation capability. However, during near-fault strong earthquakes, isolation bearings are prone to experiencing large strains. Previous studies have paid little attention to the large strain responses of HDRBs under various loading conditions, which significantly differ from their hysteresis properties under moderate shear strain loading. To address this gap, this study experimentally and numerically investigated the hysteretic responses of four full-scale HDRBs under large cyclic strains of up to 400 %. Test results indicate that the mechanical properties of HDRBs are significantly influenced by strain levels and loading protocols. The HDRBs exhibit pronounced nonlinearity in their shear force–strain relationships. Notably, as shear strain exceeds 200 %, the HDRBs demonstrate significant nonlinear hardening, strength degradation, and unloading effects. The hardening stiffness of the HDRBs is considerably higher than the post-yield stiffness. Furthermore, HDRBs show substantial variations in peak strength and degradation characteristics under different loading protocols. A numerical strategy was also developed to further explore the deformation mechanisms of the HDRBs under large strain loading conditions. • Hysteretic responses of full-scale HDRBs under large cyclic strains of up to 400 % were experimentally investigated. • Under large strain loading, using the bilinear model to simulate HDRB behavior is likely to introduce significant errors. • HDRBs exhibit significant stiffness hardening, with notable variations depending on the loading protocol. • The numerical strategy employed in this study effectively predicts the large-strain behavior of HDRBs. [ABSTRACT FROM AUTHOR]