Development and Application of a Power Law Constitutive Model for Eddy Current Dampers

Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tothe widespread implementation of ECD technology, and there is limited availability of finite element analysis (FEA)software capable of accurately modeling the behavior of ECDs. This study addresses these issues by developing anewconstitutivemodel that is both easily understandable and user-friendly for FEAsoftware. By utilizing numericalresults obtained from electromagnetic FEA, a novel power law constitutive model is proposed to capture thenonlinear behavior of ECDs. The effectiveness of the power law constitutive model is validated throughmechanicalproperty tests and numerical seismic analysis. Furthermore, a detailed description of the application process ofthe power law constitutive model in ANSYS FEA software is provided. To facilitate the preliminary design ofECDs, an analytical derivation of energy dissipation and parameter optimization for ECDs under harmonicmotionis performed. The results demonstrate that the power law constitutive model serves as a viable alternative forconducting dynamic analysis using FEA and optimizing parameters for ECDs.

DEM investigation of weathered rocks using a novel bond contact model

The distinct element method（DEM） incorporated with a novel bond contact model was applied in this paper to shed light on the microscopic physical origin of macroscopic behaviors of weathered rock, and to achieve the changing laws of microscopic parameters from observed decaying properties of rocks during weathering. The changing laws of macroscopic mechanical properties of typical rocks were summarized based on the existing research achievements. Parametric simulations were then conducted to analyze the relationships between macroscopic and microscopic parameters, and to derive the changing laws of microscopic parameters for the DEM model. Equipped with the microscopic weathering laws, a series of DEM simulations of basic laboratory tests on weathered rock samples was performed in comparison with analytical solutions. The results reveal that the relationships between macroscopic and microscopic parameters of rocks against the weathering period can be successfully attained by parametric simulations. In addition, weathering has a significant impact on both stressestrain relationship and failure pattern of rocks.

Novel extended C-m models of flow stress for accurate mechanical and metallurgical calculations and comparison with traditional flow models

Here,we developed novel extended piecewise bilinear power law(C-m)models to describe flow stresses under broad ranges of strain,strain rate,and temperature for mechanical and metallurgical calculations during metal forming at elevated temperatures.The traditional C-m model is improved upon by formulating the material parameters C and m,defined at sample strains and temperatures as functions of the strain rate.The coefficients are described as a linear combination of the basis functions defined in piecewise patches of the sample strain and temperature domain.A comparison with traditional closed-form function flow models revealed that our approach using the extended piecewise bilinear C-m model is superior in terms of accuracy,ease of use,and adaptability;additionally,the extended C-m model was applicable to numerical analysis of mechanical,metallurgical,and microstructural problems.Moreover,metallurgy-related values can be calculated directly from the flow stress information.Although the proposed model was developed for materials at elevated temperatures,it can be applied over a broad temperature range.

Effect of Particle Phase Volume, Shape and Liquid Phase Concentrations on Rheological Properties of Large Particulate-Liquid Model Food Systems by Using Ball Measuring System

Rheological properties of large particulate-liquid model food systems were studied by using the BMS （ball measuring system）. The model food systems were composed of alginate gel particles （-10mm） and a gelatinised starch solution with 1% w/w sodium chloride as a liquid phase. The effects of particle phase volume （Ф, 0-0.60）, particle shapes （cube, sphere, rod and disc） and starch concentrations （3% and 5% w/w starch） were investigated. The power law model was successfully applied to characterize the flow properties of each system and the consistency K and power law index n were obtained. The K increased and n decreased with increasing # for samples at all particle shapes at 3% w/w starch in the liquid phase. The particle effect on the viscosity is further analysed by means of the Krieger-Dougherty model and the maximum packing fraction #,, and the intrinsic viscosity [η] were obtained in each system. The Фm, depended on the particle shape, as expected. The [7] value depended on particle shape and was largely in the order of 4.04 （cube）, 3.28 （disc）, 2.56 （sphere） and 2.32 （rod） at 3% w/w starch. The [η] also depended on starch concentration and was 1.1 at 5%,6 w/w starch in the liquid phase with spherical particles. The present results show successful application of BMS to study the rheological properties of large particulate liquid food systems at relatively small scale experiment （-0.5 L） and also that existing models for suspension rheology are applicable for such food systems to a great extend.

Prediction of Cuttings-Induced Annular-Pressure Loss in Extended-Reach Wells

Drill cuttings are broken bits of solid material removed from a borehole drilled by rotary,percussion,or auger methods and brought to the surface in the drilling mud.When these cuttings enter the annulus,they have an effect on the drillingfluid rheology and density,which is,in general,quite difficult to evaluate.By introducing an empirical correlation for the rheological properties of cuttings-laden drillingfluids,this study proposes a pres-sure-loss prediction method for an extended-reach well(ERW).After verifying the accuracy of this method,a case study is considered and a sensitivity analysis is conducted assuming a yield-power lawfluid.The results show that an increased concentration of cuttings in the annulus contributes to an increased annular pressure loss.Com-pared to their effect on the drillingfluid density,cuttings have a greater impact on the drillingfluid rheology.A larger rate of penetration contributes to an increased annular pressure loss.For higher drillingfluidflow rates,the annular pressure lossfirst decreases and then it increases.In addition,the annular pressure loss becomes high-er as the cuttings’particle size decreases and the cuttings’concentration grows.

SCOURS IN FRONT OF A BREAKWATER BY BROKEN WAVES AND THEIR SIMILARITY LAW

The sea bottom in front of a breakwater is scoured under the action of broken waves,and this will affect the stability of the breakwater.In this paper,the scours of sandy seabed in front of a breakwater under the action of broken waves are investigated experimentally.The depth and range of the scouring trough at the foot of a breakwater are studied,and the influence of open foundation-bed on scouring and depositing is also discussed.In order to apply the research results to practical projects,the scale of model sediment and the scale of scours and depositions are suggested.

The effects of relative density of metal foams on the stresses and deformation of beam under bending

The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law （TG model） taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill＇s solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.

A new stabilized method for quasi-Newtonian flows

For a generalized quasi-Newtonian flow, a new stabilized method focused on the low-order velocity-pressure pairs, （bi）linear/（bi）linear and （bi）linear/constant element, is presented. The pressure projection stabilized method is extended from Stokes problems to quasi-Newtonian flow problems. The theoretical framework developed here yields an estimate bound, which measures error in the approximate velocity in the W 1,r（Ω） norm and that of the pressure in the L r＇ （Ω） （1/r ＋ 1/r＇ = 1）. The power law model and the Carreau model are special ones of the quasi-Newtonian flow problem discussed in this paper. Moreover, a residual-based posterior bound is given. Numerical experiments are presented to confirm the theoretical results.

Benzene selective hydrogenation over supported Ni(nano-) particles catalysts: Catalytic and kinetics studies

This report aims to reduce the benzene in a mixture of benzene and toluene as a model reaction using catalytic hydrogenation. In this research, we developed a series of catalysts with different supports such as Ni/HMS, Ni/HZSM-5, Ni/HZSM5-HMS, Ni/Al2O3 and Ni/SiO2. Kinetic of this reaction was investigated under various hydrogen and benzene pressures. For more study, two kinetic models have also been selected and tested to describe the kinetics for this reaction. Both used models, the power law and Langmuir-Hinshelwood, provided a good fit toward the experimental data and allowed to determine the kinetic parameters. Among these catalysts, Ni/Al2O3 showed the maximum benzene conversion （99.19%） at 130℃ for benzene hydrogenation. The lowest toluene conversion was observed for Ni/SiO2. Furthermore, this catalyst presented high selectivity to benzene （75.26%） at 130℃. The catalytic performance （activity, selectivity and stability） and kinetics evaluations were shown that the Ni/SiO2 is an effective catalyst to hydrogenate benzene. It seems that the surface properties particularly pore size are effective parameter compared to other factors such as acidity and metal dispersion in this process.

From Sequential to Parallel Growth of Cities： Theory and Evidence from Canada

This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries.

The Rule of Law Model of Internet Governance

The rule of law is the basic form of national governance and the rule of law model is the necessary direction for the governance of online society.Online society is in essence a new pattern of social relationships and structural forms comprising relationships among citizens,legal persons,organizational bodies,etc.,formed and brought together on the basis of Internet technology;and also a reflection,expansion and expression,singly or in synthesis,of various relationships in the fields of the real economy,politics,culture,society and the environment.The rule of law model of Internet governance refers to governance theories,systems and practices that employ rule of law thinking and the rule of law model to bring the elements,structures,procedures and functions of Internet governance into the scope of the rule of law and its operational track.Reviewing the tortuous course of the development of rule of law Internet governance in China,summarizing useful experience in the construction of rule of law Internet governance,and reflecting on existing legislative,law enforcement and judicial dilemmas will enable us to build up a rule of law system of online governance with comprehensive norms,effective implementation,strict supervision and strong guarantees.This will be marked by Chinese characteristics and will ensure the application of rule of law thinking and the rule of law model in governing,operating,using and safeguarding the Internet,thus achieving sound and orderly Internet operation and development along the path of the rule of law and advancing the modernization of the Internet governance system and governance capability.

China＇s Choice of Analytical Models for Its Anti-Monopoly Law

Modem analytical models for anti-monopoly laws are a core element of the application of those laws. Since the Anti-Monopoly Law of the People＇s Republic of China was promulgated in 2008, law enforcement and judicial authorities have applied different analytical models, leading to divergent legal and regulatory outcomes as similar cases receive different verdicts. To select a suitable analytical model for China＇s Anti-Monopoly Law, we need to consider the possible contribution of both economic analysis and legal formalism and to learn from the mature systems and experience of foreign countries. It is also necessary to take into account such binding constraints as the current composition of China＇s anti-monopoly legal system, the ability of implementing agencies and the supply of economic analysis, in order to ensure complementarity between the analytical model chosen and the complexity of economic analysis and between the professionalism of implementing agencies and the cost of compliance for participants in economic activities. In terms of institutional design, the models should provide a considered explanation of the legislative aims of the law＇s provisions. It is necessary, therefore, to establish a processing model of behavioral classification that is based on China＇s national conditions, applies analytical models using normative comprehensive analysis, makes use of the distribution rule of burden of proof, improves supporting systems related to analytical models and enhances the ability of public authorities to implement the law.

Improved Implicit SPH Method for simulating free surface flows of power law fluids

Implicit smoothed particle hydrodynamics method has been proposed to overcome the problem that only very small time steps can be used for high viscosity fluids(such as power law fluids)in order to obtain a stable simulation.However,the pressure field is difficult to simulate correctly with this method because the numerical high-frequency noise on the pressure field cannot be removed.In this study,several improvements,which are the diffusive term in the continuity equation,the artificial viscosity and a simplified physical viscosity term in the momentum equation,are introduced,and a new boundary treatment is also proposed.The linear equations derived from the momentum equation are large-scale,sparse and positive definite but unsymmetrical,therefore,Conjugate Gradient Squared(CGS)is used to solve them.For the purpose of verifying the validity of the proposed method,Poiseuille flows with Newtonian and power law fluids are solved and compared with exact solution and traditional SPH.Drops of different fluid properties impacting a rigid wall are also simulated and compared with VOF solution.All the numerical results obtained by the proposed method agree well with available data.The proposed method shows the higher efficiency than traditional SPH and the less numerical noise on the pressure field and better stability than implicit SPH.

Propagating characteristics of waves on a thin layer of mud

The propagating characteristics of the water and muddy waves are one of the concerns of theoretical studies because of the following facts:(1)With the development of the economy in the estuaries,local residents and government paid increasing attention to the ecological environment of the estuarine beaches The propagating characteristics of the water and muddy waves are closely related to the ecological environment,the concern of the government and the residents.(2)The propagating characteristics of the mud are the bottleneck of the study of the coastal and beach dynamics because of the complicated constitutive relation of the mud.The different constitutive models may lead to different explanations of its mechanism.Hence,the proper selection of the model is one of the keys to reveal the true kinematic properties of the mud in the estuaries.This paper first establishes a power law model of the constitutive relation of the mud.Based on this model,a gravity wave theory is proposed.According to the mechanism of the mud wave transportation,the coupled mud-water wave field can be divided into two layers.The upper layer is described as the viscous Newtonian fluid,whereas the lower high-concentration mud layer is described as the power law fluid.Next,the equations of the proposed model are discretized and the calculations are made by using the difference method.Then,the propagating characteristics are discussed,and the dispersion relations of the water and mud waves are analyzed in detail.