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Temperature-insensitive micro-displacement sensor with spindle-shaped structure single mode fiber

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Optoelectronics Letters 2025年

作者： zhang weihua MU Jinlin WANG Hao WANG Dong YU Haozheng TAO Yipeng Engineering Research Center of Optoelectronic Devices and Communication Technology，Ministry of Education， Tianjin Key Laboratory of Film Electronic and Communication Devices， School of Integrated Circuit Science and Engineering， Tianjin University of Technology Engineering Infrastructure Department，Autonomous Driving Department Xiaomi EV Company Ltd

A temperature-insensitive micro-displacement sensor based on a spindle-shaped single mode fiber (SMF) is presented and demonstrated. The SMF is bent into a balloon-shaped SMF and burned into a spindle-shaped SMF by a flame. Due to the bending of the fiber， part of the incident light leaks from the fiber core into the fiber cladding， which excites higher order cladding modes. Therefore， modal interference occurs. The experimental results show that the maximum sensitivity of the sensors is -203 pm/μm when micro-displacement varies from 0 to 80 μm. The sensors are insensitive to temperature in the range of 20-70℃. In addition， the sensors have the advantages of simple structure， low cost， small volume， high sensitivity and stability， which can be widely used in numerous high-precision industrial measurements and civil engineering structure monitoring fields.

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Causation mechanism of coal miners' human errors in the perspective of life events

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International Journal of Mining Science and Technology 2014年第4期24卷 581-586页

作者： zhang weihua School of Management China University of Mining & Technology

In order to effectively decrease the safety accidents caused by coal miners’human errors,this paper probes into the causality between human errors and life events,coping,psychological stress,psychological function,physiological function based on life events’vital influence on human errors,establishing causation mechanism model of coal miners’human errors in the perspective of life events by the researching method of structural *** research findings show that life events have significantly positive influence on human errors,with a influential effect value of 0.7945 and a influential effect path of‘‘life events—psychological stress—psychological function—physiological function—human errors’’and‘‘life events—psychological stress—physiological function—human errors’’.

关键词： Life events Human errors Structural equation Coal miners

MICROMECHANICS ANALYSIS FOR UNSATURATED GRANULAR SOILS

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Acta Mechanica Solida Sinica 2011年第3期24卷 273-281页

作者： weihua zhang Chenggang Zhao School of Civil Engineering Beijing Jiaotong University Beijing 100044 China

This paper aims at establishing an anisotropic stress expression for unsaturated pendular-state granular soils. Using the second-order fabric tensor, we formulate a micromechanics scheme of soils with statistically averaging method, and reveal that the macroscopic average stress of unsaturated granular soils in pendular-state is not isotropic. Not only is the stress from contact forces anisotropic due to the fabric, but also the capillary stress is directional dependent, which is different from the common point that the capillary stress is isotropic. The capillary stress of unsaturated pendular-state granular soils is determined by the orientation distribution of con- tact normals, so it is closely related to the initial and induced anisotropy of soils. Finally, DEM numerical simulations of triaxial compression tests of pendular-state soils at different degrees of saturation are used to verify the existence of above anisotropy of stresses.

关键词： unsaturated granular soils pendular state average stress fabric capillary stress,anisotropy

Delay-dependent decentralized H_∞ filtering for uncertain interconnected systems

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Journal of Systems Engineering and Electronics 2008年第4期19卷 766-774页

作者： Chen Ning Gui weihua zhang Xiaofeng School of Information Science and Engineering Central South Univ. Changsha 410083 P. R. China

This article considers delay dependent decentralized H∞ filtering for a class of uncertain interconnected systems, where the uncertainties are assumed to be time varying and satisfy the norm-bounded conditions. First, combining the Lyapunov-Krasovskii functional approach and the delay integral inequality of matrices, a sufficient condition of the existence of the robust decentralized H∞ filter is derived, which makes the error systems asymptotically stable and satisfies the H∞ norm of the transfer function from noise input to error output less than the specified up-bound on the basis of the form of uncertainties. Then, the above sufficient condition is transformed to a system of easily solvable LMIs via a series of equivalent transformation. Finally, the numerical simulation shows the efficiency of the main results.

关键词： interconnected systems H∞ filtering delay-dependent LMI.

Structure overset grid method and its applications to simulation of multi-body separation

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Science China(Physics,Mechanics & Astronomy) 2015年第9期58卷 68-75页

作者： zhang HaiRui FAN JingJing YUAN Wu zhang weihua College of Aerospace Science and Engineering National University of Defense Technology China Academy of Lanch Vehicle Technology Supercomputing Center Computer Network Information Center Chinese Academy of Sciences

This paper proposes an automatic structure overset grid method, which utilizes the hole-surface optimization with one-step searching, wall-surface grid oversetting, and dynamic overset grid approaches to achieve the high adaptability of overset grids for complex multi-body aircrafts. Specifically, based on the automatic structure overset grids, the method first solves the coupling of Navier-Stokes(N-S) unsteady flow equation and 6DOF motion equation, and establishes the multi-body collision model. Then, the numerical simulation of unsteady flow for complex aircrafts' multi-body separation, the simulation of multi-body separating trajectory and the separation safety analysis are accomplished. Thus, the method can properly handle practical engineering problems including the wing/drop tank separation, aircraft/mount separation, and cluster bomb projection. Experiments show that our numerical results match well with experimental results, which demonstrates the effectiveness of our methods in solving the multi-body separation problem for aircrafts with complex shapes.

关键词： dynamic overset grids multi-body separations CFD

Pseudospectral method based trajectory optimization and fairing rejection time analysis of solid launch vehicle

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Science China(Technological Sciences) 2009年第11期52卷 3198-3206页

作者： XUAN Ying zhang weihua zhang YuLin College of Aerospace and Material Engineering National University of Defense TechnologyChangsha 410073China

The problem of real-time trajectory optimization for small solid launch vehicle of operational responsive space (ORS) was studied by using pseudospectral method. According to the characteristic of the trajectory design, the dynamics model was set up in the inertia right-angled reference frame, and the equation and parameter at the orbit injection point were simplified and converted. The infinite dimension dynamic optimal control problem was converted to a finite dimension static state optimization problem and the algorithm reduced the complexity so as to become a general algorithm in trajectories optimization. With the trajectories optimization of a three-stage solid vehicle with a liquor upper stage as example, the model of the trajectory optimization was set up and simulations were carried out. The results demonstrated the advantage and validity of the pseudospectral method. The rejection time of fairing was also analyzed by the simulation results, and the optimal flight procedure and trajectory were obtained.

关键词： pseudospectral method solid launch vehicle trajectory optimization rejection time of fairing

基于REOF的不同量级降雨侵蚀力时空变化——以重庆市为例

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西南大学学报（自然科学版） 2025年第1期47卷 163-177页

作者：靳军英王林金铁生张卫华西南大学资源环境学院重庆400715

研究重庆市不同地理分区内各量级降雨侵蚀力的时空变化特征,为该地区进行更加精准的区域性水土流失防治工作提供理论依据。选取1981-2020年重庆市31个站点逐日降雨数据,利用旋转经验正交函数(Rotated Empirical Orthogonal Function,RE... 详细信息

研究重庆市不同地理分区内各量级降雨侵蚀力的时空变化特征,为该地区进行更加精准的区域性水土流失防治工作提供理论依据。选取1981-2020年重庆市31个站点逐日降雨数据,利用旋转经验正交函数(Rotated Empirical Orthogonal Function,REOF)对降雨侵蚀力进行地理分区,并结合R/S、5年滑动平均、Mann-Kendall检验等方法,分析各分区不同量级降雨侵蚀力时空变化。结果表明:①重庆市降雨侵蚀力可分为6个地理区域(Ⅰ-Ⅵ区);②重庆市多年平均降雨侵蚀力为5784.04 MJ·mm/(hm^(2)·h·a),不同降雨侵蚀力从大到小依次为:大雨、暴雨、中雨、大暴雨;③大雨侵蚀力在Ⅰ-Ⅲ区和Ⅴ-Ⅵ区占主导优势,暴雨侵蚀力在Ⅳ区占主导优势。各分区中,中雨、大雨及暴雨侵蚀力主要集中在5-9月,大暴雨侵蚀力集中在6-8月;④各区不同量级降雨侵蚀力年际变化从小到大依次为:中雨、大雨、暴雨、大暴雨;同一量级降雨侵蚀力的整体变化趋势均不显著;Hurst指数表明,中雨侵蚀力在Ⅰ和Ⅴ区、大雨侵蚀力在Ⅱ和Ⅴ区、大暴雨侵蚀力在Ⅰ和Ⅲ区呈强持续上升趋势;⑤中雨、大雨及大暴雨侵蚀力在渝东南、渝东北占主导优势,暴雨侵蚀力在渝西以及重庆中部占主导优势,且Ⅰ区酉阳和秀山、Ⅱ区开州、Ⅲ区北碚和铜梁、Ⅳ区璧山和永川、Ⅴ区巫溪和云阳及Ⅵ区忠县是不同量级降雨侵蚀力的高峰中心。通过对重庆各分区不同量级降雨侵蚀力的分析,明确了可能引起土壤侵蚀的主要雨型、高发时期和潜在风险较高的地区,可为区域水土流失动态监测和水土保持措施的合理制定提供参考。

关键词：降雨侵蚀力时空变化旋转经验正交分解法 MK非参数趋势检验 R/S分析法

Step-by-Step Numerical Prediction of Aerodynamic Noise Generated by High Speed Trains

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Chinese Journal of Mechanical Engineering 2022年第2期35卷 251-264页

作者： Tian Li Deng Qin Ning Zhou weihua zhang State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

In this paper,the unsteady flow around a high-speed train is numerically simulated by detached eddy simulation method(DES),and the far-field noise is predicted using the Ffowcs Williams-Hawkings(FW-H)acoustic *** reliability of the numerical calculation is verified by wind tunnel *** superposition relationship between the far-field radiated noise of the local aerodynamic noise sources of the high-speed train and the whole noise source is *** the aerodynamic noise of high-speed trains is derived from its different components,a stepwise calculation method is proposed to predict the aerodynamic noise of high-speed *** results show that the local noise sources of high-speed trains and the whole noise source conform to the principle of sound source energy *** the head,middle and tail cars of the high-speed train as noise sources,different numerical models are established to obtain the far-field radiated noise of each aerodynamic noise *** far-field total noise of high-speed trains is predicted using sound source superposition.A step-by-step calculation of each local aerodynamic noise source is used to obtain the superimposed value of the far-field *** is consistent with the far-field noise of the whole train model’s aerodynamic *** averaged sound pressure level of the far-field longitudinal noise measurement points differs by 1.92 *** step-by-step numerical prediction method of aerodynamic noise of high-speed trains can provide a reference for the numerical prediction of aerodynamic noise generated by long marshalling high-speed trains.

关键词： High-speed train Aerodynamic noise Sound source superposition Numerical prediction

Dynamics of high speed wheel/rail system and its modelling

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Chinese Science Bulletin 2007年第11期52卷 1566-1575页

作者： zhang ShuGuang zhang weihua JIN XueSong Transportation Bureau of Railway Ministry of China Beijing 100844 China State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China

With the fast increasing of train speed the interactions among the train,the track,and the power cate-nary system become very strong. Such interactions are also strongly coupled with the action of high speed airflow due to the high speed running. Hence,the existing research methods and numerical al-gorithms of railway vehicle/track systems are not fully available for characterizing the transient dy-namic and long-term behaviors of train/track at higher speed. The present paper reviews the existing studies on coupling dynamics of railway vehicle/track,and clarifies their advantages and disadvan-tages and then puts forward an innovation stratagem for high speed railway based on rolling contact of wheel/rail systems. In the innovation stratagem,a comprehensive dynamic model of wheels/rails sys-tems is developed to simultaneously consider the track system,the train,the rolling contact of wheel/rail,the catenary/pantograph system,and the high speed airflow with the train. The motion equations of the subsystems and their coupling boundaries are given and discussed. For the reliability and safety of the high speed train in service,the long-term behavior of the structures of the train and the track is considered in the comprehensive model. Moreover,a generalized failure model,consider-ing the structures and the materials and working in the comprehensive dynamic model of wheels/rails system,as well as the simulation system of structure failure of the high speed train/track is established. Consequently,the present studies on the dynamics of the coupled vehicle/track will be further and largely extended.

关键词：铁轨火车悬链线故障模拟车轮