A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depend...A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depends on the resonant frequency of the passive third harmonic superconducting cavity.It is important that the operating frequency of the cavity is within the design range and the cavity has reasonable mechanical stability.A simulation method for the multiphysics coupled analysis has been developed based on the ANSYS code.Multiphysics coupled simulations have been performed under different conditions,such as etching,evacuation,cooling,and preloading.Analyses of mechanical modes and structural stress have been executed.A possible stiffening ring method for the two-cell superconducting niobium cavity has been investigated.In this paper,we present a multiphysics coupled analysis of the third harmonic cavity using a finite element analysis code.The results of the analysis show that a reliable frequency for the cavity after electron beam welding is 1498.033 MHz,and the corresponding frequency of the pre-tuning goal is 1496.163 MHz.A naked cavity is a reasonable option based on structural stress and mechanical modal analyses.A frequency range of±500 kHz and limiting tolerable displacement of±0.35 mm are proposed for the design of the frequency tuner.展开更多
In this paper,a design is presented for a high-speed,high-power motor for a four-legged robot actuator that was optimized using the weighted sum method(WSM)based on the Taguchi method,and the response surface method(R...In this paper,a design is presented for a high-speed,high-power motor for a four-legged robot actuator that was optimized using the weighted sum method(WSM)based on the Taguchi method,and the response surface method(RSM).First,output torque,torque constant,torque ripple,and efficiency were selected as objective functions for the optimized design.The sampling method was implemented to use a mixed orthogonal array and the single response characteristics of each objective function were compared using the Taguchi method.Moreover,to consider the multi-response characteristic of the objective functions,WSM was applied.Second,the 2D finite element analysis result of the RSM was compared with that using the WSM.Finally,an experiment was carried out on the manufactured motor and the optimized model is presented here.展开更多
The paper deals with mathematical modeling of induction hardening of internal surfaces of steel tubes used for transportation of loose materials.First a comparison of two ways of induction surface hardening was provid...The paper deals with mathematical modeling of induction hardening of internal surfaces of steel tubes used for transportation of loose materials.First a comparison of two ways of induction surface hardening was provided.Then the coupled electromagnetic and temperature fields analysis was provided by means of single-owned packages.Quite good convergence between measurements done on especially built laboratory stand and computations was achieved.展开更多
Roads are exposed to various degradation mechanisms during their lifetime.The pavement deterioration caused by the surrounding environment is particularly severe in winter when the humidity and subfreezing temperature...Roads are exposed to various degradation mechanisms during their lifetime.The pavement deterioration caused by the surrounding environment is particularly severe in winter when the humidity and subfreezing temperatures prevail.Frost heave-induced damage is one of the winter-related pavement deterioration.It occurs when the porewater in the soil is exposed to freezing temperatures.The study of frost heave requires conducting a multiphysics analysis,considering the thermal,mechanical,and hydraulic fields.This paper presents the use of a coupled thermo-mechanical approach to simulate frost heave in saturated soils.A function predicting porosity evolution is implemented to couple the thermal and mechanical field analyses.This function indirectly considers the effect of the water seepage inside the soil.Different frost heave scenarios with uniform and non-uniform boundary conditions are considered to demonstrate the capabilities of the method.The results of the simulations indicate that the thermo-mechanical model captures various processes involved in the frost heave phenomenon,such as water fusion,porosity variation,cryogenic suction force generation,and soil expansion.The characteristics and consequences of each process are determined and discussed separately.Furthermore,the results show that non-uniform thermal boundaries and presence of a culvert inside the soil result in uneven ground surface deformations.展开更多
Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a...Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a good pre-research cavity for CSNS to learn SRF technology.In this paper,the sequential approach of analysis and optimization performed for the structural design of 648 MHz SSR prototype are presented.Methods The COMSOL Multiphysics is used to perform the multiphysics analysis of jacketed cavity.Firstly,the mechanical performance of bare cavity is estimated,and then,several stiffeners are added to strengthen the cavity.After that,the Lorentz coefficient and helium fluctuation df/dp of jacketed cavity are optimized.At last,the tuning sensitivity and mechanical performance of maximum allowable working pressure are calculated.Results The final results of Lorentz coefficient and df/dp are-5.06 Hz/(MV/m)^(2)and 0.3 Hz/mbar,respectively,and the tuning range of jacketed cavity is larger than±1000 kHz at 2 K.Conclusion The structural design of a 648 MHz SSR prototype is performed in this paper.The Lorentz coefficient and df/dp are carefully optimized.The simulation result shows all mechanical performance satisfies the design goals very well.展开更多
Owing to the relatively low stifness of the slide and the considerable deformation under support force,the fuid–structure interaction(FSI)phenomenon in aerostatic slides is generally pronounced.This phenomenon afects...Owing to the relatively low stifness of the slide and the considerable deformation under support force,the fuid–structure interaction(FSI)phenomenon in aerostatic slides is generally pronounced.This phenomenon afects the performance of static pressure slides,particularly those with high load-carrying capacity and low stifness.However,most existing methods for analyzing the efect of FSI on the stifness of static pressure slides are iterative and computationally expensive.To address this issue,a novel direct method is proposed for evaluating the stifness of static pressure slides while considering FSI.This method can quickly and precisely obtain numerical solutions.Furthermore,the accuracy of the proposed method is validated through experiments.Based on the developed FSI model,the efects of normal force and flm thickness on the normal stifness of aerostatic slides are also investigated.展开更多
基金supported by the National Natural Science Foundation of China(No.11335014)
文摘A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depends on the resonant frequency of the passive third harmonic superconducting cavity.It is important that the operating frequency of the cavity is within the design range and the cavity has reasonable mechanical stability.A simulation method for the multiphysics coupled analysis has been developed based on the ANSYS code.Multiphysics coupled simulations have been performed under different conditions,such as etching,evacuation,cooling,and preloading.Analyses of mechanical modes and structural stress have been executed.A possible stiffening ring method for the two-cell superconducting niobium cavity has been investigated.In this paper,we present a multiphysics coupled analysis of the third harmonic cavity using a finite element analysis code.The results of the analysis show that a reliable frequency for the cavity after electron beam welding is 1498.033 MHz,and the corresponding frequency of the pre-tuning goal is 1496.163 MHz.A naked cavity is a reasonable option based on structural stress and mechanical modal analyses.A frequency range of±500 kHz and limiting tolerable displacement of±0.35 mm are proposed for the design of the frequency tuner.
基金supported by the Industrial Strategic Technology Development Program(10070171,Development of core technology for advanced locomotion/manipulation based on high-speed/power robot platform and robot intelligence)funded By the Ministry of Trade,Industry&Energy(MI,Korea).
文摘In this paper,a design is presented for a high-speed,high-power motor for a four-legged robot actuator that was optimized using the weighted sum method(WSM)based on the Taguchi method,and the response surface method(RSM).First,output torque,torque constant,torque ripple,and efficiency were selected as objective functions for the optimized design.The sampling method was implemented to use a mixed orthogonal array and the single response characteristics of each objective function were compared using the Taguchi method.Moreover,to consider the multi-response characteristic of the objective functions,WSM was applied.Second,the 2D finite element analysis result of the RSM was compared with that using the WSM.Finally,an experiment was carried out on the manufactured motor and the optimized model is presented here.
基金Item sponsored by Polish Ministry of Science and Higher Education in a framework of grant project N N510 256338
文摘The paper deals with mathematical modeling of induction hardening of internal surfaces of steel tubes used for transportation of loose materials.First a comparison of two ways of induction surface hardening was provided.Then the coupled electromagnetic and temperature fields analysis was provided by means of single-owned packages.Quite good convergence between measurements done on especially built laboratory stand and computations was achieved.
基金the Swedish Transport Administration (Trafikverket)for the financial support of this research work (No.TRV 2020/19896).
文摘Roads are exposed to various degradation mechanisms during their lifetime.The pavement deterioration caused by the surrounding environment is particularly severe in winter when the humidity and subfreezing temperatures prevail.Frost heave-induced damage is one of the winter-related pavement deterioration.It occurs when the porewater in the soil is exposed to freezing temperatures.The study of frost heave requires conducting a multiphysics analysis,considering the thermal,mechanical,and hydraulic fields.This paper presents the use of a coupled thermo-mechanical approach to simulate frost heave in saturated soils.A function predicting porosity evolution is implemented to couple the thermal and mechanical field analyses.This function indirectly considers the effect of the water seepage inside the soil.Different frost heave scenarios with uniform and non-uniform boundary conditions are considered to demonstrate the capabilities of the method.The results of the simulations indicate that the thermo-mechanical model captures various processes involved in the frost heave phenomenon,such as water fusion,porosity variation,cryogenic suction force generation,and soil expansion.The characteristics and consequences of each process are determined and discussed separately.Furthermore,the results show that non-uniform thermal boundaries and presence of a culvert inside the soil result in uneven ground surface deformations.
文摘Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a good pre-research cavity for CSNS to learn SRF technology.In this paper,the sequential approach of analysis and optimization performed for the structural design of 648 MHz SSR prototype are presented.Methods The COMSOL Multiphysics is used to perform the multiphysics analysis of jacketed cavity.Firstly,the mechanical performance of bare cavity is estimated,and then,several stiffeners are added to strengthen the cavity.After that,the Lorentz coefficient and helium fluctuation df/dp of jacketed cavity are optimized.At last,the tuning sensitivity and mechanical performance of maximum allowable working pressure are calculated.Results The final results of Lorentz coefficient and df/dp are-5.06 Hz/(MV/m)^(2)and 0.3 Hz/mbar,respectively,and the tuning range of jacketed cavity is larger than±1000 kHz at 2 K.Conclusion The structural design of a 648 MHz SSR prototype is performed in this paper.The Lorentz coefficient and df/dp are carefully optimized.The simulation result shows all mechanical performance satisfies the design goals very well.
基金The National Key Research and Development Program of China(2022YFB3402705)The National Natural Science Foundation of China(52105439).
文摘Owing to the relatively low stifness of the slide and the considerable deformation under support force,the fuid–structure interaction(FSI)phenomenon in aerostatic slides is generally pronounced.This phenomenon afects the performance of static pressure slides,particularly those with high load-carrying capacity and low stifness.However,most existing methods for analyzing the efect of FSI on the stifness of static pressure slides are iterative and computationally expensive.To address this issue,a novel direct method is proposed for evaluating the stifness of static pressure slides while considering FSI.This method can quickly and precisely obtain numerical solutions.Furthermore,the accuracy of the proposed method is validated through experiments.Based on the developed FSI model,the efects of normal force and flm thickness on the normal stifness of aerostatic slides are also investigated.
