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Mechanical Analysis of a No-insulation Pancake Coil with the Overband During a Quench

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Acta Mechanica Solida Sinica 2022年第3期35卷 357-366页

作者： Donghui Liu Yunkai Tang Dongke Li Huadong Yong key laboratory of mechanics on disaster and environment in western China Ministry of Education of ChinaLanzhou UniversityLanzhou 730000China Department of mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

The no-insulation(NI)winding approach can remarkably improve the thermal stability of high-temperature superconducting ***,mechanical issues have gradually become a key factor to block the development of NI magnets in recent *** paper mainly analyzes the effect of the overband on the mechanical behaviors of an NI coil during a quench.A numerical model including a quench model combined with a three-dimensional homogeneous mechanical model is employed to study the change of stress in the coil without and with the over band during a local *** results show that the overband has an obvious effect on the stress distribution as the heater is located at the outer turn of the ***,the values of stress in the coil are also affected by the ***,the effects of the thickness of the overband and the location of the heater on the mechanical behaviors of the coil are also *** is worth noting that the overband can remarkably reduce the hoop and axial tensile stresses of the coil during a quench。

关键词： No-insulation coil Overband Quench Stress

Aeroelastic dynamics stability of rotating sandwich annular plate with viscoelastic core layer

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Applied Mathematics and mechanics(English Edition) 2016年第1期37卷 107-120页

作者： Xingzhe WANG Longfei LI Youhe ZHOU key laboratory of mechanics on disaster and environment in western China the Ministry of Education of China College of Civil Engineering and MechanicsLanzhou University Department of Theoretical and Applied mechanics School of Mining and Safety EngineeringShandong University of Science and Technology

A dynamic model for a rotating sandwich annular plate with a viscoelastic core layer is developed. All fundamental equations and boundary conditions are estab- lished based on Hamilton＇s principle, and the rotation effect and viscoelastic properties of the sandwich structure are taken into account. The aerodynaxnics force acting on the plate is described by a rotating damping model, and the constitutive behavior of the viscoelastic core layer is formulated by the frequency-dependent complex modulus. The effects of geometrical and material parameters on frequencies and damping of forward and backward traveling waves and the dynamic stability for the rotating sandwich plate axe numerically analyzed by means of Galerkin＇s method. The results show that the critical and flutter speeds of the rotating plate can he increased at some certain parameters of the viscoelastic core layer.

关键词： laminate buckling vibration numerical analysis critical speed flutter speed

Electromagnetic-thermal-mechanical characteristics with active feedback control in a high-temperature superconducting noinsulation magnet

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Science China(Physics,mechanics & Astronomy) 2022年第9期65卷 92-103页

作者： Donghui Liu Dongke Li Weiwei Zhang Huadong Yong Youhe Zhou key laboratory of mechanics on disaster and environment in western China Ministry of Education of ChinaLanzhou UniversityLanzhou 730000China Department of mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

High-temperature superconducting(HTS) magnets consisting of no-insulation(NI) double-pancake coils(DPCs) with high thermal stability have been proposed for use in the preparation of high-field magnets. However, increased ramp time is a known disadvantage of the NI approach. To solve this problem, a proportional and integral(PI) active feedback control has been proposed in the charging experiments of the NI magnet. In this study, the electromagnetic-thermal-mechanical characteristics of an NI magnet with and without PI are analyzed to ensure the safety and reliability of PI control. Due to the increase in the radial current of the magnet, the turn-to-turn loss energy of the magnet with PI is more than twice that without PI. However, the magnetization loss energy of the magnet has a small difference with and without PI. It can be also found that the NI magnet with PI has a large temperature rise, and thus it has a low thermal stability margin. Moreover, in the high field, the hoop stress and hoop strain peaks of a magnet with PI are larger than those without PI. Thus, PI control can induce a relatively high risk of mechanical damage in the applications of NI magnets.

关键词： no-insulation magnet active feedback control loss energy temperature rise strain and stress

Three-dimensional simulation of the coupled electromagnetic-mechanical responses in a no-insulation racetrack coil

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Science China(Technological Sciences) 2024年第11期67卷 3485-3498页

作者： LI DongKe CHANG ZhiXiang TANG YunKai LIU DongHui YONG HuaDong ZHOU YouHe key laboratory of mechanics on disaster and environment in western China Ministry of Education of ChinaLanzhou UniversityLanzhou 730000China Department of mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

This study investigates the coupled behavior of the mechanical and electromagnetic responses of a high-temperature superconducting(HTS)no-insulation(NI)racetrack coil.A three-dimensional(3D)equivalent circuit network model and mechanical model with nonlinear contact are incorporated into the coupled *** stress and separation of adjacent turns under a high magnetic field are analyzed by considering the electromagnetic force and cooling *** numerical results demonstrate that the straight and curved parts of the racetrack coil exhibit distinct mechanical *** a strong external magnetic field,the separation between adjacent turns reduces the charging delay of the *** maximum stress occurs in the transition regions between the curved and straight *** straight part exhibits a larger rotation angle,while the separation regions between adjacent turns are relatively fewer in those *** curved part shows a higher proportion of separation regions in the steady *** different separation areas in the straight and curved parts also result in distinct turn-to-turn losses during the charging ***,a comparative study is conducted on the influence of residual currents induced by ***,the effects of overband and inner diameter on the separation behavior are investigated.

关键词： high-temperature superconducting coil coupled electromagnetic-mechanical responses separation

Two-step homogenization for the effective thermal conductivities of twisted multi-filamentary superconducting strand

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Applied Mathematics and mechanics(English Edition) 2022年第5期43卷 689-708页

作者： Yongbin WANG Huadong YONG Youhe ZHOU Department of mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China key laboratory of mechanics on disaster and environment in western China Ministry of Education of ChinaLanzhou UniversityLanzhou 730000China

For the accurate prediction of the effective thermal conductivities of the twisted multi-filamentary superconducting strand,a two-step homogenization method is *** on the distribution of filaments,the superconducting strand can be decomposed into a set of concentric cylinder *** layer is a two-phase composite composed of the twisted filaments and copper *** the first step of homogenization,the representative volume element(RVE)based finite element(FE)homogenization method with the periodic boundary condition(PBC)is adopted to evaluate the effective thermal conductivities of each *** the second step of homogenization,the generalized self-consistent method is used to obtain the effective thermal conductivities of all the concentric cylinder *** accuracy of the developed model is validated by comparing with the local and full-field FE ***,the effects of the twist pitch on the effective thermal conductivities of twisted multi-filamentary superconducting strand are studied.

关键词： superconducting strand multi-filamentary two-step homogenization effective thermal conductivity

Tunability of Band Gaps of Programmable Hard-Magnetic Soft Material Phononic Crystals

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Acta Mechanica Solida Sinica 2022年第5期35卷 719-732页

作者： Bo Li Wei Yan Yuanwen Gao Department of mechanics and Engineering Science College of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China key laboratory of mechanics On environment and disaster in western China The Ministry of Education of ChinaLanzhou UniversityLanzhou730000China

In this paper,the elastic wave band gap characteristics of two-dimensional hard-magnetic soft material phononic crystals(HmSM-PnCs)under the applied magnetic field are ***,the relevant material parameters of hard-magnetic soft materials(HmSMs)are obtained by the experimental *** the finite element model of the programmable HmSM-PnCs is established to calculate its band structure under the applied magnetic *** effects of some factors such as magnetic field,structure thickness,structure porosity,and magnetic anisotropy encoding mode on the band gap are *** results show that the start and stop frequencies and band gap width can be tunable by changing the magnetic *** magnetic anisotropy encoding mode has a remarkable effect on the number of band gaps and the critical magnetic field of band *** addition,the effect of geometric size on PnC structure is also *** the increase of the structure thickness,the start and stop frequencies of the band gap increase.

关键词： Phononic crystal Hard-magnetic soft materials Magnetic field Magnetic anisotropy encoding modes Structure thickness Band gap

A high-order accurate wavelet method for solving Schrdinger equations with general nonlinearity

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Applied Mathematics and mechanics(English Edition) 2018年第2期39卷 275-290页

作者： Jiaqun WANG Xiaojing LIU Youhe ZHOU key laboratory of mechanics on disaster and environment in western China the Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China State key laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China

A sampling approximation for a function defined on a bounded interval is proposed by combining the Coiflet-type wavelet expansion and the boundary extension technique. Based on such a wavelet approximation scheme, a Galerkin procedure is developed for the spatial discretization of the generalized nonlinear Schr6dinger （NLS） equa- tions, and a system of ordinary differential equations for the time dependent unknowns is obtained. Then, the classical fourth-order explicit Runge-Kutta method is used to solve this semi-discretization system. To justify the present method, several widely considered problems are solved as the test examples, and the results demonstrate that the proposed wavelet algorithm has much better accuracy and a faster convergence rate in space than many existing numerical methods.

关键词： wavelet Galerkin method generalized nonlinear SchrSdinger (NLS) equation high-order convergence

Tunability of Band Gaps in Two-Dimensional Phononic Crystals with Magnetorheological and Electrorheological Composites

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Acta Mechanica Solida Sinica 2021年第1期34卷 40-52页

作者： Gang Zhang Yuanwen Gao key laboratory of mechanics on environment and disaster in western China The Ministry of Education of ChinaLanzhou UniversityLanzhou730000China Department of mechanics and Engineering Science College of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China

The elastic wave propagation properties of phononic crystals(PnCs)composed of an elastic matrix embedded in magnetorheological and electrorheological elastomers are studied in this *** tunable band gaps and transmission spectra of these materials are calculated using the finite element method and supercell *** variations in the band gap characteristics with changes in the electric/magnetic fields are *** numerical results show that the electric and magnetic fields can be used in combination to adjust the band gaps *** start and stop frequencies of the band gap are obviously affected by the electric field,and the band gap width is regulated more significantly by the magnetic *** widest and highest band gap can be obtained by combined application of the electric and magnetic *** addition,the band gaps can be moved to the low-frequency region by drilling holes in the PnC,which can also open or close new band *** results indicate the possibility of multi-physical field regulation and design optimization of the elastic wave properties of intelligent PnCs.

关键词： Phononic crystal.Band gap Magnetic field Electric field Combined adjustment

Creep effect on cellular uptake of viral particles

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Chinese Science Bulletin 2014年第19期59卷 2277-2281页

作者： Jizeng Wang Long Li Youhe Zhou key laboratory of mechanics on disaster and environment in western China Ministry of Education School of Civil Engineering and Mechanics Lanzhou University

Receptor diffusion on cell membrane is usually believed as a major factor that controls how fast a virus can enter into host cell via ***,when receptors are densely distributed around the binding site so that receptor recruiting through diffusion is no longer energetically favorable,we thus hypothesize that another effect,the creep deformation of cytoskeleton,might turn to play the dominant role in relaxing the engulfing *** order to deeply understand this mechanism,we propose a viscoelastic model to investigate the dynamic process of virus engulfment retarded by the creep deformation of cytoskeleton and driven by the binding of ligand-receptor bonds after overcoming resistance from elastic deformation of lipid membrane and *** on this new model,we predict the lower bound of the ligand density and the range of virus size that allows the complete engulfment,and an optimal virus size corresponding to the smallest wrapping ***,these predictions can be reduced to the previous predictions based on simplified membrane models by taking into account statistical thermodynamic *** results presented in this study may be of interest to toxicologists,nanotechnologists,and virologists.

关键词：病毒颗粒宿主细胞蠕变效应细胞膜受体粘弹性模型摄取细胞骨架蠕变变形