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This paper presents a new hysteresis model for post-installed fasteners anchoring nonstructural components (NSCs) to concrete structures, or structural concrete members to each other, such that they must resist seismic shear actions. Focusing on NSCs, the hysteresis model was initially calibrated with quasi-static tests of an expansion anchor, and was implemented in the numerical model of a shake-table NSC assembly to predict its response. The initially calibrated model predicted the experimental acceleration response of the NSCs during two tests, with RMS errors of less than 10%, but overestimated the amplitude up to 50%. Minor tuning of the model using the first test results reduced the RMS and amplitude errors for the second test to 5% and 15%, respectively. It was concluded that the developed anchor model constitutes a simple and powerful tool for numerically representing the hysteresis of anchor connections subjected to shear and evaluating the response of the NSCs they fix. [ABSTRACT FROM AUTHOR]

In the fast tool servo (FTS) system for microstructure surface cutting, the dynamic voltage hysteresis of piezoelectric actuators (PEAs) and the cutting force produced in the manufacturing affect the driving accuracy and the cutting performance. For a multi-input-single-output (MISO) cutting system, in this paper, a dynamic hysteresis model based on a rate-dependent Prandtl–Ishlinskii model is proposed. A backpropagation neural network (BPNN) is established to describe the cross-coupling effect between the applied voltage and external load. An inverse dynamic model is developed to compensate the nonlinearity of PEAs. The accuracy of the model and its inverse is discussed and the performance of the inverse feedforward compensator is validated through experiments.

Various seismic analysis methods are being used to predict the response of structures to earthquakes. Although nonlinear dynamic analysis (NDA) is considered an ideal method to represent the most realistic behavior of a structure among these various methods, correct results can be derived only when the analysis model is carefully developed by a knowledgeable person. It is particularly important to properly implement the behavior characteristics depending on the reversed cyclic load in the NDA of a building made of reinforced concrete (RC) moment frames. This study evaluated the hysteresis model suitable for NDA of existing RC moment frames, and 45 analysis models were reviewed, in which the pivot, concrete, and Takeda hysteresis models were applied differently to beams and columns. The pivot model was evaluated as the most reliable hysteresis model for each structural member by comparing and analyzing not only the responses of the entire frame but also the responses of column and beam members focusing on energy dissipation. However, this model can have practical limitations in that the parameters associated with the reinforcement detailing and applied loads need to be defined in detail. The analysis model applying Takeda to the beam, which predicted the average response at a reliable level compared to the reference model, was identified as a practical alternative when it is difficult to apply the pivot model to all frame members.

• Hysteresis model of grooved fit piping joint is developed and validated based on quasi-static test results. • Generic hysteresis model is further developed based on the calibration results of each specimen. • Finite element modeling method of suspended piping system is proposed and calibrated using shaking table test results. Robust internal building pipeline is one of the most important non-structural components for reducing post-earthquake secondary disasters and maintaining normal use of buildings after an earthquake. The seismic damage of piping systems can result in the loss of firefighting abilities or lead to failure of water supplies and drainage systems in a building which can have serious implications for emergency rescue, post-disaster response and reconstruction work. In this study, moment-rotation hysteresis curves of grooved-fit piping-joints are obtained by quasi-static cyclical tests. Moment-rotation hysteresis models of piping-joints are developed using the Pinching4 uniaxial constitutive in the finite element software OpenSees. The calibrated model parameters are obtained using test data. The developed hysteresis models can accurately reproduce the moment-rotation hysteresis curves obtained in the experiments and simulate moment time-history during the loading process. The predicted accumulated energy dissipation is consistent with the test results. Using this observation, generic piping-joint moment-rotation hysteresis models are further developed and parameter values used to define the generic hysteresis model are obtained. A numerical model of a piping system is then developed using the generic hysteresis model. The numerical results confirm that the model can be used to reproduce the nonlinear behavior of a piping system under cyclic loading with high accuracy. The developed numerical model was further calibrated using shaking table test results. Comparisons between numerical and experimental responses demonstrate that the developed numerical model can be used to analyze the seismic response of a suspended piping system using grooved-fit joints. [ABSTRACT FROM AUTHOR]

• A multi-stage hysteresis (MSH) model is proposed for magnetorheological dampers. • Steady-state and transient finite element methods are combined. • An equivalent weighted mean magnetic field hypothesis is proposed and validated. • The MSH model effectively predicts the behaviour of magnetorheological dampers. • The MSH model has a smooth transition in different stages. An accurate theoretical model is the basis for the structural design and parameter optimisation of magnetorheological dampers (MRDs). Owing to the inability of existing models to accurately describe the motion characteristics of MRDs in the entire region, a multi-stage hysteresis (MSH) model for low-frequency conditions was proposed. The MSH model comprised a magnetic chain model and Bi-Viscous model to describe the characteristics of the pre-yield and yield flow stages, respectively. The local loss and inertia effect were considered in the MSH model. Steady-state and transient finite element methods were combined to analyse the magnetic field distribution during MRD motion, and an equivalent weighted mean magnetic field hypothesis was proposed to reduce the quantisation error and time consumption. The experimental results demonstrate the prediction effectiveness of the MSH model. Moreover, the quantitative evaluation parameters of the flow and hysteresis regions were obtained and the variation trend of the MRD main design indices with the magnetic circuit parameters was analysed. The obtained velocity distribution parameters indicate a smooth transition of the stages in the MSH model from a qualitative perspective. The mixed mode incorporates the physical properties of the shear and flow modes, but cannot simply be regarded as a linear superposition of these two modes. [Display omitted] [ABSTRACT FROM AUTHOR]

Magnetic shape memory alloy materials have a bright prospect in micro-nano intelligent actuators, however, the hysteresis in these materials is prevalent and damages the positioning precision of these actuators. In this paper, a Pi-Sigma neural network model with a modified backlash-like operator is developed to capture the dynamic hysteresis of the magnetic shape memory alloy material actuator. The modified backlash-like operator is designed for the multi-value-mapping and asymmetrical hysteresis of the magnetic shape memory alloy material actuator. The rate-dependent hysteresis of the magnetic shape memory alloy material actuator is described via the Pi-Sigma neural network model. Experimental results show that the effectiveness of the proposed model outperforms the Krasnosel'skii-Pokrovskii model. [ABSTRACT FROM AUTHOR]

Abstract A new test-rig to analyze drilling dynamics is presented in this article. Although simple, the test-rig can represent satisfactorily some phenomena observed in deep water drilling. The test-rig results are analyzed and stick-slip cycles are explained in detail. The explanations are in agreement with available field data found in the literature. One stick-slip cycle is extracted and analyzed thoroughly. Then, other cycles are presented to show the variability of the obtained experimental data. Finally, a model that might take into account hysteric effects is proposed for the bit-rock interaction. The parameters of the proposed model are identified using the experimental data. drill-string test-rig bit-rock interaction model drill-string dynamics experimental identification hysteresis model. Highlights • A new test rig is proposed to analyze drilling dynamics. • The test rig reproduces axial/torsional vibrations of a real scale drilling operation. • The test rig allows a detailed analysis of stick-slip cycles. • Axial and Torsional vibrations are coupled for the case studied. • A hysteric model is proposed for the bit-rock interaction. [ABSTRACT FROM AUTHOR]

Highlights • A modified hysteresis model considering the influence of mechanical stress and magnetic peak induction is proposed. • A novel device to carry out the magnetic property testing under large compressive stress is designed. Abstract Non-oriented electrical steel is widely used in the manufacturing of motor stators. The magnetic property will be influenced by the residual stress induced from manufacturing processes. The classical Jile-Atherton hysteresis model with constant parameters is widely used to describe the magnetization characteristic of ferromagnetic materials. In the model, the parameter a represents the domain density, k is the pinning factor reflecting the strength of the pinning effect, α is the domain coupling parameter affecting the slope of the mid-segment of the hysteresis loop and C is the coefficient of reversibility. However, all the four parameters are influenced by residual stress. Furthermore, the influence of magnetic peak induction on parameters can’t be ignored according to our work. The classical Jile-Atherton hysteresis model cannot reflect the influence of residual stress and magnetic peak induction. In this paper, a modified residual stress dependent Jile-Atherton hysteresis model was proposed, whose parameters are extended to functions related to residual stress and magnetic peak induction. A novel device was designed to carry out magnetic property testing experiments under large stress. The parameters were identified by a MATLAB program and the influence of residual stress and magnetic peak induction was analyzed. The accuracy of parameters was validated by experiments, which showed that the modified model worked well in describing the magnetization characteristic under different stresses and magnetic peak inductions. This could provide some guidance for the manufacturing processes of motor stators. [ABSTRACT FROM AUTHOR]

The complex behavior of reinforced concrete frames with infill walls under earthquake loads requires a realistic conceptual model that recognizes changes in strength and stiffness occurring during loading. Accordingly, a new hysteresis model is developed in this article for such reinforced concrete frames to investigate the ultimate damage state given a ground motion. Using this model, the infilled frame can be represented as a single-degree-of-freedom system for computationally efficient dynamic in-plane response analysis. A backbone curve is developed first to provide an envelope within which load–displacement paths occur. Then, the load reversal effects are described and integrated into the backbone curve to obtain the hysteresis model. The hysteresis model developed in this article is checked using data from 11 laboratory experiments carried out by other researchers. The applicability of the hysteresis model is also illustrated on a laboratory specimen that was tested by other researchers under base excitation. [ABSTRACT FROM AUTHOR]

Recent bridge failures due to earthquakes around world have renewed interest in understanding the nonlinear dynamic behaviour of existing and new bridge structures. Analysis of reinforced concrete bridge columns under cyclic loading requires proper identification and calibration of suitable hysteresis models. Columns being the most critical components of a bridge structure, knowledge on the hysteresis behaviour of bridge columns are of primary importance in determining the earthquake response of bridges. This paper aims at tracing the hysteresis behaviour of RC bridge columns using Bouc-Wen type model. Experimental data from literature is used for validation of the proposed modelling approach. A good correlation is observed between the observed behaviour and the calculated values. In addition, the model is found to estimate the dissipated energy with reasonable accuracy. Sensitivity analysis is carried out to ascertain the influence of different parameters on the accuracy of the estimation from the model. Finally, upper and lower bounds for each parameter have been specified based on the range of variation of the parameters observed in this study. [ABSTRACT FROM AUTHOR]

The estimation of LiFePO4/graphite battery states suffers from the prominent hysteresis phenomenon between the respective open-circuit voltage curves towards charging and discharging. A lot of hysteresis models have been documented to investigate the hysteresis mechanism. This paper reviews and deeply interprets four non-electrochemical hysteresis models and some improvements. These models can be conveniently incorporated into commonly used equivalent circuit models to reproduce battery behaviors. Through simulation and experimental comparisons of voltage predictions and state-of-charge estimations, the pros and cons of these models are presented. [ABSTRACT FROM AUTHOR]

Summary: Reinforced concrete (R/C) frame buildings designed according to older seismic codes represent a large part of the existing building stock worldwide. Their structural elements are often vulnerable to shear or flexure‐shear failure, which can eventually lead to loss of axial load resistance of vertical elements and initiate vertical progressive collapse of a building. In this study, a hysteretic model capturing the local shear response of shear‐deficient R/C elements is described in detail, with emphasis on post‐peak behaviour; it differs from existing models in that it considers the localisation of shear strains after the onset of shear failure in a critical length defined by the diagonal failure planes. Additionally, an effort is made to improve the state of the art in post‐peak shear response modelling, by compiling the largest database of experimental results for shear and flexure‐shear critical R/C columns cycled well beyond the onset of shear failure and/or up to the onset of axial failure, and developing empirical relationships for the key parameters defining the local backbone post‐peak shear response of such elements. The implementation of the derived local hysteretic shear model in a computationally efficient beam‐column finite element model with distributed shear flexibility, which accounts for all deformation types, will be presented in a companion paper. [ABSTRACT FROM AUTHOR]

Summary: To achieve accurate state‐of‐charge (SoC) estimation for LiFePO4 batteries, the effects of temperature, hysteresis, and thermal evolution are elaborately modeled. Open‐circuit voltage is regarded as the sum of electromotive force and hysteresis potential ( Vh), where electromotive force is constructed as the function of SoC and temperature and Vh is reproduced with a geometrical model. By simulating battery heat generation and dissipation, a thermal evolution model is established and exploited for open‐circuit voltage and parameter identification. Then, on the basis of a second‐order equivalent circuit model, 2 SoC estimation schemes are proposed: One scheme uses the recursive least square with forgetting factor algorithm and off‐line equivalent circuit model parameters derived by the differential evolution algorithm; the other scheme resorts to the adaptive extended Kalman filter (EKF) and online tuned parameters. Experiments validate the effectiveness of the hysteresis model and the thermal evolution model. In contrast to a joint EKF estimator, experimental results under different temperatures and initial states suggest that both the proposed estimators are superior to the joint EKF estimator. Benefiting from the online updated parameters, the adaptive EKF estimator behaves best for giving consistent SoC‐tracking performance under different conditions. [ABSTRACT FROM AUTHOR]

This paper proposes an innovative type of two-level yielding steel coupling beams (TYSCB) to improve the seismic performance of coupled shear wall systems. The proposed TYSCB consists of two key components: shear-yielding beam and bending-yielding beam. For a minor earthquake, the former is expected to yield to dissipate energy while the latter still stays in elastic to provide the stiffness demand. Under a severe earthquake, both the shear and bending-yielding beams are designed to yield to dissipate seismic energy. Experiments are carried out on four full-scale TYSCB specimens to investigate their seismic behavior and yielding mechanism. These specimens vary in lengths, heat treatments of welding joints, web forms and strengthening of end joints. The experimental results show that TYSCBs have fully developed hysteresis behavior and the preferred yielding sequence. The equivalent damping coefficients of all the tested specimens reach up to 45%. The energy dissipation ability increase by 94% with only 27.3% reduction in stiffness compared with traditional complete steel coupling beams under minor earthquakes. On the other hand, its stiffness can increase by 37.5% with only 44.1% reduction in energy dissipation capacity compared with fuse steel coupling beams under minor earthquakes. A trilinear hysteretic model is proposed to reasonably simulate the cyclic behavior of TYSCBs. A nonlinear finite element model is also developed and validated against the test results. The hysteretic and finite element models are to facilitate the application of TYSCBs in the seismic design of shear wall systems. [ABSTRACT FROM AUTHOR]

As the shoe durability is affected directly by the dynamic force/pressure between the shoe and its working environments (i.e., the contact ground and the human foot), a footwear testing system should replicate correctly this interaction force profile during gait cycles. Thus, in developing a robotic foot for footwear testing, it is important to power multiple foot joints and to control their output torque to produce correct dynamic effects on footwear. The cable conduit mechanism (CCM) offers great advantages for designing this robotic foot. It not only eliminates the cumbersome actuators and significant inertial effects from the fast-moving robotic foot but also allows a large amount of energy/force to be transmitted/propagated to the compact robotic foot. However, CCMs cause nonlinearities and hysteresis effects to the system performance. Recent studies on CCMs and hysteresis systems mostly addressed the position control. This paper introduces a new approach for modelling the torque transmission and controlling the output torque of a pair of CCMs, which are used to actuate the robotic foot for footwear testing. The proximal torque is used as the input signal for the Bouc–Wen hysteresis model to portray the torque transmission profile while a new robust adaptive control scheme is developed to online estimate and compensate for the nonlinearities and hysteresis effects. Both theoretical proof of stability and experimental validation of the new torque controller have been carried out and reported in this paper. Control experiments of other closed-loop control algorithms have been also conducted to compare their performance with the new controller effectiveness. Qualitative and quantitative results show that the new control approach significantly enhances the torque tracking performance for the system preceded by CCMs. [ABSTRACT FROM AUTHOR]

This article investigates the efficiency of a new generation smart isolation system, namely shape memory alloy wire-based lead rubber bearing, for the seismic response control of long-span cable-stayed bridge systems under near-fault ground motions. The constitutive model of shape memory alloy wire-based lead rubber bearings is coded and implemented into OpenSees as a new user element. This user element can accurately predict the re-centering capability and energy dissipation capacity of shape memory alloy wire-based lead rubber bearing under different excitations. The Sutong cable-stayed bridge in China, with a main span of 1088 m, is taken as an example. Results reveal that implementing shape memory alloy wires into lead rubber bearings can effectively increase the self-centering property and, as a result, reduce the residual deformation in shape memory alloy wire-based lead rubber bearings under near-fault ground motions. Shape memory alloy wires lead to an increase in the horizontal stiffness and energy dissipation capacity of shape memory alloy wire-based lead rubber bearings. The deck displacement is restricted effectively, and a superior structural performance is achieved in terms of the deck acceleration. Shape memory alloy wire-based lead rubber bearings can effectively reduce the base shear and base moment of the towers. However, it is observed that an increase in the shape memory alloy wire diameter may have negligible effect on the deck acceleration, tower base shear and moment, and in some cases, on the pier base shear and moment. [ABSTRACT FROM AUTHOR]

In this paper, we propose the G model, a new approach for modeling hysteresis based on simple equations and having its treatment more direct than, for instance, the well-known Preisach and Jiles–Atherton models. As main basis, the shape of the external hysteresis curves is strongly considered, allowing a correct behavior of magnetic induction evolution inside the hysteresis cycle. Minor loops can also be represented with good accuracy. Comparisons with the Jiles–Atherton model and experimental data are shown in order to validate the proposed methodology. [ABSTRACT FROM AUTHOR]

In this paper, a method for the assessment of magnetic properties of ferromagnetic materials at low magnetic field values is presented. The knowledge of these properties is crucial for the design of magnetically shielded rooms that must be effective against low-frequency external magnetic field disturbances on the order of 0.1– 1~\mu \mathrm T . The considered shielding structure is composed by a number of layers made of different high-permeability ferromagnetic sheets as grain-oriented electric steel and nickel–iron soft magnetic alloy. The ferromagnetic materials in this region follow the Rayleigh law that is a quadratic law between magnetic flux density and the applied field. Two material-dependent parameters of this law are obtained by a characterization of the material behaviour performed on a scaled prototype of a magnetically shielded room. The procedure is validated on a multilayer shield structure. [ABSTRACT FROM AUTHOR]

This paper presents the simple analytical modeling for switched flux memory machine to provide in-depth insight into its working mechanism. The analytical approach is based on the slotless open-circuit air-gap flux density and the slotted air-gap relative permeance calculations for a doubly salient structure. In addition, due to low coercivity and highly nonlinear hysteresis curve at the second quadrant, the piecewise and virtual-linear hysteresis models of AlNiCo permanent magnet (PM) are presented to determine the PM working point. This combined analytical solution allows rapid calculation of several electromagnetic characteristics, e.g., air-gap flux density and back electromotive force. The effectiveness of the analytical method is validated by both finite-element results and measurements. [ABSTRACT FROM AUTHOR]

By measuring 13 grades of neodymium (NdFeB), we obtained their temperature-dependent magnetic properties from 25 °C to 120 °C. Furthermore, a piecewise linear hysteresis model for NdFeB magnet is generalized to a temperature-dependent one, where temperature coefficients are introduced to consider deterioration of magnetic performance due to rising temperature. The movement of working point on hysteresis loops when temperature changes is discussed. The model is validated by massive experimental measurement of NdFeB specimens. The accuracy of the model is about 5% in the range of 25 °C–120 °C. The proposed model can be applied in electromagnetic and thermal analysis of permanent magnet motor. [ABSTRACT FROM AUTHOR]

Ultra-precision fast tool servo (FTS) machining technology is an effective method for complex surface microstructure machining. However, as for a single degree-offreedom FTS, it can only achieve a high-rate reciprocating movement in one direction; thus, it cannot realize ultraprecision machining for some complex microstructural surface. Therefore, a novel flexure-based fast tool servo device composed of two platforms and three branched chains is proposed in this work, which aims to realize a robotic ultra-precision machining with XYZ translational precision motion. Each of the branched chain is made up of a prismatic pair, two hook hinges, and a connecting rod. The FTS mechanism design and modeling are carried out firstly; then, the FTS device characterization in terms of statics analysis and modal analysis is conducted; in order to suppress the hysteresis nonlinearity and improve the positioning precision, a new repetitivecompensated PID controller combined with an inverted modified Prandtl-Ishlinskii model is proposed to handle this issue. It indicates that the displacement amplification ratio is 3.87; thus, the workspace can reach to [- 85, 85]∪[- 80,80]∪[0,120]μm3, and the closed-loop positioning precision is 600 nm, which will be considered to fulfill practical FTS machining tasks. [ABSTRACT FROM AUTHOR]

The temperature drift of the current sensor with an air gap limits its measurement accuracy, so a ferromagnetic design is presented to improve the temperature characteristics of the current sensor by an air-gapped magnetic field intensity self-compensation. In this paper, the magnetostriction and thermal expansion are introduced into a hysteresis model within the temperature range from 258 to 358 K, and the relationship between the permeability and the air-gapped length of amorphous alloy is analyzed. The results show that the air-gapped length increases as the temperature increases, resulting in the air-gapped magnetic field intensity weakened. Moreover, the permeability of amorphous alloy increases as the temperature increases, resulting in the air-gapped magnetic field intensity strengthened. Hence, the air-gapped magnetic field intensity can be self-compensated with the amorphous alloy. The effectiveness of the design is verified experimentally with 1–10 mm air-gapped amorphous cores. In addition, in order to analyze the air-gapped magnetic field intensity changes more accurately, a new hysteresis modeling method is proposed, which can overcome the disadvantages of a J-A model for the minor hysteresis curve simulations and a Preisach model for the major hysteresis curve simulations. [ABSTRACT FROM PUBLISHER]

In this paper, a design scheme for a novel energy-saving contactor using two-phase magnetic material is presented. A magnetization model using two-phase magnetic material was built with mathematical modeling and the theory of the Preisach model. The conversion mechanism was analyzed in order to reveal the relationship between the remanence and coercivity. The manufacturing process of the material is also described. Based on the differences between the transformation characteristics of the two-phase magnetic material in the permanent magnet and the soft magnetic field, an energy-saving contactor was designed by using two-phase magnetic material based on the remnant magnetism of 75 Oe. The simulation and experiment results show that the proposed energy-saving contactor functions well. [ABSTRACT FROM AUTHOR]

This paper proposes a new electrically controlled magnetic variable-speed gearing (EC-MVSG) machine, which is capable of providing controllable gear ratios for hybrid electric vehicle (HEV) applications. The key design feature involves the adoption of a magnetic gearing structure and acceptance of the memory machine flux-mnemonic concept. Hence, the proposed machine can not only offer a gear-shifting mechanism for torque and speed transmission, but also provide variable gear ratios for torque and speed variation. The electromagnetic design is studied and discussed. The finite-element method is developed with the hysteresis model to verify the validity of the machine design.

Hysteresis behaviors are inherent characteristics of piezoelectric ceramic actuators. The classical Duhem model (CDM) as a popular hysteresis model has been widely used, but cannot precisely describe rate-dependent hysteresis behaviors at high-frequency and high-amplitude excitations. To describe such behaviors more precisely, this paper presents a modified Duhem model (MDM) by introducing trigonometric functions based on the analysis of the existing experimental data. The MDM parameters are also identified by using the nonlinear least squares method. Six groups of experiments with different frequencies or amplitudes are conducted to evaluate the MDM performance. The research results demonstrate that the MDM can more precisely characterize the rate-dependent hysteresis behaviors comparing with the CDM at high-frequency and high-amplitude excitations.

Giant magnetostrictive actuators (GMA) driven by giant magnetostrictive material (GMM) has some advantages such as a large strain, high precision, large driving force, fast response, high reliability, and so on, and it has become the research hotspot in the field of microdrives. Research shows there is a nonlinear, intrinsic relationship between the output signal and the input signal of giant magnetostrictive actuators because of the strong coupling characteristics between the machine, electromagnetic field, and heat. It is very complicated to construct its nonlinear eigenmodel, and it is the basis of the practical process of giant magnetostrictive material to construct its nonlinear eigenmodel. Aiming at the design of giant magnetostrictive actuators, the magnetization model based on a free-energy hysteresis model has been deeply researched, constructed, and put forward by Smith, which combines Helmholtz−Gibbs free energy and statistical distribution theory, to simulate the hysteresis model at medium or high driving strengths. Its main input and output parameters include magnetic field strength, magnetization, and mechanical strain. Then, numerical realization and verification of the magnetization model are done by the Gauss−Legendre integral discretization method. The results show that the magnetization model and its numerical method are correct, and the research results provide a theoretical basis for the engineering application of giant magnetostrictive material and optimized structure of giant magnetostrictive material actuators, which have an important practical application value.

With the aim to model the seismic behavior of steel reinforced concrete (SRC) frame columns, in this research, hysteresis and skeleton curves were obtained based on the damage test results of SRC frame columns under low cyclic repeat loading and the hysteretic behavior of the frame columns was further analyzed. Then, the skeleton curve and hysteresis loops were further simplified. The simplified skeleton curve model was obtained through the corresponding feature points obtained by mechanical and regression analysis. The nonlinear combination seismic damage index, which was developed by the test results and can well reflect the effect of the loading path and the number of loading cycle of SRC frame columns, was used to establish the cyclic degradation index. The strength and stiffness degradation rule of the SRC frame columns was analyzed further by considering the effect of the accumulated damage caused by an earthquake. Finally, the hysteresis model of the SRC frame columns was established, and the specific hysteresis rules were given. The validity of the developed hysteresis model was verified by e comparison between the calculated results and the test results. The results showed that the model could describe the hysteresis characteristics of the SRC frame columns under cyclic loading and provide guidance for the elastoplastic time-history analysis of these structures.

This paper introduces a comparative study of two different hysteresis models, limiting loop model and elemental operator model. The former is regarded as a mathematical approach based on the traditional Preisach model. To circumvent the difficulty of determining the distribution function in the Preisach model, the data of the limiting hysteresis loop and a function transform on the Preisach diagram are employed. The latter is a physical method which adopts a vectorial elemental operator with biaxial anisotropy based on the magnetization mechanisms of the ferromagnetic material. These two models are analyzed and compared in terms of the underlying principle, numerical implementation, and calculation accuracy in this paper. To verify the introduced models, the magnetic properties of non-oriented silicon steel Lycore-140 and soft magnetic composite material Somaloy 500 under alternating excitations are measured and compared with simulated results, which show the validity and practicability of the models but with different calculation accuracy and speed. [ABSTRACT FROM AUTHOR]

The classical Preisach hysteresis model and its modifications are time consuming to implement due to the determination of the weight function. Another defect of the Preisach-based model is that it could only be an approximation in the absence of the congruency property. For such reasons, this paper proposes a hysteresis model identification method based on support vector regression which could be a promising alternative in practical applications. Support vector machine is attractive in regression analysis due to its strong generalization capability. A four-stage identification procedure is implemented and key techniques are introduced in detail. The penalty parameter and the kernel parameter are optimized using grid search and cross-validation method. The influences of data scaling and parameter optimization are analyzed. An identified hysteresis model of aluminum nickel cobalt alloy is evaluated and verified with the criteria of mean squared error and identified time. [ABSTRACT FROM AUTHOR]

This paper presents the characterization and hysteresis modeling of magnetorheological (MR) damper with meandering type valve. The meandering type MR valve, which employs the combination of multiple annular and radial flow passages, has been introduced as the new type of high performance MR valve with higher achievable pressure drop and controllable performance range than similar counterparts in its class. Since the performance of a damper is highly determined by the valve performance, the utilization of the meandering type MR valve in an MR damper could potentially improve the damper performance. The damping force characterization of the MR damper is conducted by measuring the damping force as a response to the variety of harmonic excitations. The hysteresis behavior of the damper is identified by plotting the damping force relationship to the excitation displacement and velocity. For the hysteresis modeling purpose, some parts of the data are taken as the training data source for the optimization parameters in the neuro-fuzzy model. The performance of the trained neuro-fuzzy model is assessed by validating the model output with the remaining measurement data and benchmarking the results with the output of the parametric hysteresis model. The validation results show that the neuro-fuzzy model is demonstrating good agreement with the measurement results indicated by the average relative error of only around 7%. The model also shows robustness with no tendency of growing error when the input values are changed. [ABSTRACT FROM AUTHOR]

This paper describes a methodology for modelling the nonlinear, inelastic load–displacement behaviour of two-way spanning unreinforced masonry walls subjected to out-of-plane loading. The model utilises a simplified macroblock approach that starts with the assumption of a collapse mechanism based on the wall’s boundary conditions. It then treats the wall as having zero tensile strength and assumes that the resistance comes entirety from two gravity-based resistance components: elastic rigid block rocking, and inelastic friction, with the total load resistance of the wall taken as the sum of these individual components. Analytical expressions for calculating the load and displacement capacities of the elastic rocking component of response are derived from the principles of statics using an integration approach well suited for the treatment of two-way mechanisms. Expressions for the associated frictional capacity component are obtained using the virtual work method. Comparison of the theoretical load–displacement response with experimentally measured data is favourable as demonstrated using data obtained via quasistatic cyclic tests on two-way spanning walls; the model is shown to provide an acceptable lower bound estimate of actual behaviour. The developed approach could be used to construct pushover curves for a range of different collapse mechanisms and therefore has the potential to be assimilated into a simplified displacement-based seismic design/assessment technique for two-way spanning walls against out-of-plane collapse. [ABSTRACT FROM AUTHOR]

This paper introduces a temperature-dependent hysteresis model based on a vectorial elemental operator with temperature-sensitive spontaneous magnetization and biaxial anisotropy for the soft ferrites. Detailed analysis of the temperature-dependent magnetic properties of one elemental operator has been presented thereafter. With the help of the proposed vector elemental operator and the 2-D Gaussian distribution function, the temperature-dependent magnetic hysteresis of soft ferrites can be simulated. This model is validated by the substantial agreement between the simulated and measured major hysteresis loops of a soft ferrite sample Siemens 4C65 at different temperatures with slight acceptable error. [ABSTRACT FROM AUTHOR]

The on-load magnetization characteristics of a newly developed partitioned stator switched flux hybrid magnet memory machine are comprehensively analyzed in this paper. First, the open-circuit and on-load permanent magnet magnetization performances are evaluated and compared. The mismatch of the required demagnetizing currents between open-circuit and on-load cases is identified. Then, the on-load demagnetization behavior of low coercive force (LCF) magnet is disclosed by the frozen permeability method. Besides, a numerical solution for the refinement of LCF magnet sizing is presented by a proposed virtual linear hysteresis model so as to effectively prevent the undesired on-load demagnetization. Finally, an optimized prototype is tested to verify the theoretical analyses. [ABSTRACT FROM AUTHOR]

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The undesired hysteresis exists widely in smart-material actuators, which significantly reduces the accuracy and response speed of the actuators. In this paper, the static experiment of our previously developed hybrid vibration isolator (HVI) employing piezoelectric actuator is implemented to choose appropriate preload of the HVI. The preload-dependent hysteresis of the HVI is also proved in the static experiment. To achieve the hysteresis linearization control of the HVI, two linearization methods named the feedforward linearization and feedforward compensation and PI feedback hybrid linearization control are presented, respectively, which are based on the Bouc-Wen model and corresponding parameter identification model. To evaluate the effectiveness of the proposed linearization controllers for the HVI, the experiments are implemented. The experiment results demonstrate that both linearization controllers for the HVI can linearize the hysteresis characteristics and improve the HVI control accuracy. In addition, the feedforward compensation and PI feedback hybrid linear controller can achieve higher linearity than feedforward compensation controller. [ABSTRACT FROM AUTHOR]