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Finite element analysis for wellbore stability of transversely isotropic rock with hydraulic-mechanical-damage coupling

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Science China(Technological Sciences) 2017年第1期60卷 133-145页

作者： WANG YongLiang LIUZhanLi yang HengLin ZHUANG zhuo Drilling Research Institute China National Petroleum Corporation Beijing 100195 China

The finite element analysis （FEA） technology by hydraulic-mechanical-damage （HMD） coupling is proposed in this paper for wellbore stability analysis of transversely isotropic rock, developed basing on the recently established FEA technology for iso- tropic rock. The finite element （FE） solutions of numerical wellbore model, damage tensor calculation and Pariseau strength criterion for transversely isotropic rock are developed for researching the wellbore failure characteristics and computing the collapse and fracture pressure of laminated rock as shale reservoirs. The classic Blot constitutive for rock as porous medium is introduced to establish a set of FE equations coupling with elastic solid deformation and seepage flow. To be in accord with the inclined wellbore situation, the coordinate transformation for global, wellbore, in-situ stress and transversely isotropic for- mation coordinate systems is established for describing the in-situ stress field and the results in laminated rock. To be in accord with the practical situation, a three-dimensional FIE model is developed, in which several other auxiliary technologies are com- prehensively utilized, e.g., the typical Weibull distribution function for heterogeneous material description and adaptive tech- nology for mesh refinement. The damage tensor calculation technology for transversely isotropic rock are realized from the well-developed continuum damage variable of isotropic rock. The rock is subsequently developed into a novel conceptual and practical model considering the stress and permeability with the damage. The proposed method utilizing Parisean strength cri- terion fully reflects the strength parameters parallel or perpendicular to bedding of the transversely isotropic rock. To this end, an effective and reliable numerically three-step FEA strategy is well established. Numerical examples are given to show that the proposed method can establish efficient and applicable FE model and be suitable for analyz

关键词： finite element analysis wellbore stability transversely isotropic rock damage tensor hydraulic-mechanical-damagecoupling

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Power allocation of cooperative amplify-and-forward communications with multiple relays

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 65-69页

作者： WU zhuo yang Hong-bing School of Communication and Information Engineering Shanghai University Shanghai 200072 China

Cooperative diversity is one of the most effective ways to mitigate the fading effect of wireless channels and obtain the spatial gain in wireless networks. In this paper, an optimal power allocation （OPA） scheme for a cooperative communication system using the amplify-and-forward （AF） transmit strategy with multiple relay users is proposed by minimizing the bit-error-rate （BER） at the destination under the constraint of the total transmit power of both the source user and the relay users. Simutation resutts indicate that the proposed power allocation method can achieve significant BER performance improvement than using the equal power allocation （EPA） scheme, while still attains low complexity. The system performance is improved significantly with the increasing of the number of relay users at high signal-noise ratio （SNR）. However, at low SNR, the system performance decreases when the relay number increases. Thus, an adaptive relay selection scheme may be used to choose the appropriate relay numbers in different transmission scenarios to provide system performance improvement and keep the power allocation scheme with low complexity.

关键词： cooperative communication AF EPA PA multiple relays BER

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STEADY-STATE AND IDLE OPTIMIZA-TION OF INTERNAL COMBUSTION ENGINE CONTROL STRATEGIES FOR HYBRID ELECTRIC VEHICLES

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 58-64页

作者： WANG Feng MAO Xiaojian yang Lin zhuo Bin School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China

A novel steady-state optimization （SSO） of internal combustion engine （ICE） strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles, in which the ICE efficiency, the efficiencies of the electric motor （EM） and the energy storage device are all explicitly taken into account. In addition, a novel idle optimization of ICE strategy is implemented to obtain the optimal idle operating point of the ICE and corresponding optimal parking generation power of the EM using the view of the novel SSO of ICE strategy. Simulations results show that potential fuel economy improvement is achieved relative to the conventional one which only optimized the ICE efficiency by the novel SSO of ICE strategy, and fuel consumption per voltage increment decreases a lot during the parking charge by the novel idle optimization of ICE strategy.

关键词： Hybrid electric vehicle Internal combustion engine Steady-state optimization Idle optimization Energy conversion

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Augmented Virtual Stiffness Rendering of a Cable-driven SEA for Human-Robot Interaction

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 714-723页

作者： Ningbo Yu Wulin Zou Wen Tan zhuo yang IEEE Institute of Robotics and Automatic Information Systems Nankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University Haihe Education Park

Human-robot interaction(HRI) is fundamental for human-centered robotics, and has been attracting intensive research for more than a decade. The series elastic actuator(SEA) provides inherent compliance, safety and further benefits for HRI, but the introduced elastic element also brings control difficulties. In this paper, we address the stiffness rendering problem for a cable-driven SEA system, to achieve either low stiffness for good transparency or high stiffness bigger than the physical spring constant, and to assess the rendering accuracy with quantified metrics. By taking a velocity-sourced model of the motor, a cascaded velocity-torque-impedance control structure is established. To achieve high fidelity torque control, the 2-DOF(degree of freedom) stabilizing control method together with a compensator has been used to handle the competing requirements on tracking performance, noise and disturbance rejection,and energy optimization in the cable-driven SEA system. The conventional passivity requirement for HRI usually leads to a conservative design of the impedance controller, and the rendered stiffness cannot go higher than the physical spring constant. By adding a phase-lead compensator into the impedance controller,the stiffness rendering capability was augmented with guaranteed relaxed passivity. Extensive simulations and experiments have been performed, and the virtual stiffness has been rendered in the extended range of 0.1 to 2.0 times of the physical spring constant with guaranteed relaxed passivity for physical humanrobot interaction below 5 Hz. Quantified metrics also verified good rendering accuracy.

关键词： Cable actuation impedance control physical human-robot interaction relaxed passivity series elastic actuator stabilizing 2-DOF(degree of freedom) controllers

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MULTIPLE ELECTRONIC CONTROL UNITS CALIBRATION SYSTEM BASED ON EXPLICIT CALIBRATION PROTOCOL AND J1939 PROTOCOL

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 42-46页

作者： ZHU Keqing XU Quankui yang Lin zhuo Bin Institute of Automotive Electronic Technology Shanghai Jiaotong University Shanghai 200030 China

The rising number of electronic control units （ECUs） in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol （XCP） and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network （CAN） are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.

关键词： Electronic control unit (ECU) Calibration Explicit calibration protocol (XCP) J1939 communication protocol Controlled area network (CAN)

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A fuse-based DC circuit breaker with vacuum interrupter enhanced by an external transverse magnetic field

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High Voltage 2024年第3期9卷 710-720页

作者： Yu Xiao Yi Wu Yifei Wu Fei yang Mingzhe Rong zhuo yang State Key Laboratory of Electrical Insulation and Power Equipment School of Electric EngineeringXi'an Jiaotong UniversityXi'anChina State Grid Shaanxi Electric Power Company Limited Xi'anChina

Due to the increasing power system capacity,the interruption of large fault currents has gradually become a major challenge in power *** the moment,such currents are interrupted mainly via circuit breakers based on the method of active current ***,these types of circuit breakers tend to be costly and *** possible alternative—a fuse-based circuit breaker with current commutation process enhanced by an external transverse magnetic field(ETMF)—is proposed by the *** main advantage lies in the fast current commutation achieved by an ETMF-enhanced three-stage increase of the vacuum arc *** study of the current commutation process is mainly represented by the authors,and the influencing factors of the current commutation—contact opening speed and ETMF current—are *** last,the proposed circuit breaker is verified by an experiment,whose results show that a short-circuit current of 42 kA can be interrupted within just 2 ms.

关键词： vacuum transverse interrupt

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Application of high energy X-ray diffraction and Rietveld refinement in layered lithium transition metal oxide cathode materials

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Nano Research 2023年第7期16卷 9954-9967页

作者： zhuo yang Yong Lu Xiaomeng Liu Fujun Li Jun Chen Renewable Energy Conversion and Storage Center(RECAST) Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China

Layered lithium transition metal oxide(LTMO)cathode materials have attracted much attention for lithium-ion batteries and are shining in the current *** a clear structure-performance relationship is necessary for the performance improvement of LTMO cathode *** combination of synchrotron X-ray diffraction(XRD)with high intensity and XRD Rietveld refinement is powerful for revealing the structural characteristics of LTMO cathode *** review summarizes the application of high energy XRD and Rietveld refinement in LTMO cathode materials,including the brief introduction of synchrotron XRD and Rietveld refinement and their applications in understanding the structural evolution related to the synthetic,thermal runaway,cycling,and high-rate charge/discharge process of LTMO cathode *** XRD can provide insights into the intermediates and reaction paths in the synthesis process,the origin of thermal runaway,the mechanism of structural decay during cycles,and the structural evolution during high-rate charging/*** works should focus on the development of higher intensity X-rays to gain more in-depth insights into the intrinsic relationship between their structural characteristics and properties.

关键词： synchrotron X-ray diffraction Rietveld refinement layered cathode materials transition metal oxide lithium-ion batteries

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Scheme for Realizing Probabilistic Teleportation of Bipartite Atomic State via Cavity QED

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Communications in Theoretical Physics 2006年第4期45卷 621-624页

作者： DONG Ping yang Ming CAO zhuo-Liang School of Physics ＆ Material Science Anhui University Hefei 230039 China

We present a physical scheme for realizing probabilistic teleportation of bipartite atomic states via cavity QED. This scheme requires only a nonmaximally entangled pair used as quantum channel, so we reduce the requi... 详细信息

关键词： bipartite atomic state teleportation nonmaximally entangled state cavity QED

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Investigation on Metallurgical Factors Controlling Charpy Impact Toughness in 1Cr21Ni5Ti Duplex Stainless Steel

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Journal of Iron and Steel Research International 2009年第2期16卷 73-79页

作者： yang zhuo-yue SU Jie WANG Ya-ming Institute of Structure Materials Central Iron and Steel Research Institute Beijing 100081 China Steel Tube Department China Iron and Steel Research Institute Group Beijing 100081 China

Based on the fact that toughness degradation occurred in 1Cr21Ni5Ti duplex stainless steel during slow cooling in a temperature interval of 400-600 ℃ following brazed welding, a simulated embrittlement treatment was utilized to evaluate its emhrittlement tendency. Accumulated experiences have shown that high Ti and A1 contents led frequently to severe toughness deterioration. To elucidate this phenomenon, four heats with various Ti and Al contents were prepared in laboratory-scale melts, which were used to investigate the inherent embrittlement nature. The results have shown that 550 ℃ aging led only to a modest toughness reduction, whereas, aging around 475 ℃ resulted in ferrite embrittlement, regardless of Ti, A1 levels. However, high Ti, A1 levels reduced the austenite phase, which, in the case of its inferior shape and distribution due to insufficient hot deformation, failed to resist cleavagetype cracks initiated in the ferrite phase. Increasing hot-forged areas reduction could modify the shape and distribution of austenite, resulting in the enhanced resistance of the austenite to the cleavage-type cracks, which have been confirmed to be beneficial for brittlement suppression of 1Cr21Ni5Ti duplex stainless steel.

关键词： 1Cr21Ni5Ti steel emhrittlement Ti content AI content impact toughness

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STRUCTURE PARAMETERS DESIGN AND PERFORMANCE TEST OF FUEL INJECTION SYSTEM

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Chinese Journal of Mechanical Engineering 2006年第3期19卷 407-411页

作者： WU Changshui YU Jinxia yang Lin zhuo Bin Institute of Automotive Electronic Technology Shanghai Jiaotong University Shanghai 200030 China

Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.

关键词： High pressure common rail fuel injection system Structure parameters design Variance analysis

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