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Reliability Design for Impact Vibration of Hydraulic Pressure Pipeline Systems

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Chinese Journal of mechanical Engineering 2013年第5期26卷 1050-1055页

作者： ZHANG Tianxiao LIU Xinhui college of mechanical Science and Engineering Jilin University

The research of reliability design for impact vibration of hydraulic pressure pipeline systems is still in the primary stage,and the research of quantitative reliability of hydraulic components and system is still *** the condition of having obtained the numerical characteristics of basic random parameters,several techniques and methods including the probability statistical theory,hydraulic technique and stochastic perturbation method are employed to carry out the reliability design for impact vibration of the hydraulic pressure *** the instantaneous pressure pulse of hydraulic impact in pipeline,the reliability analysis model of hydraulic pipeline system is established,and the reliability-based optimization design method is *** proposed method can reflect the inherent reliability of hydraulic pipe system exactly,and the desired result is *** reliability design of hydraulic pipeline system is achieved by computer programs and the reliability design information of hydraulic pipeline system is *** research proposes a reliability design method,which can solve the problem of the reliability-based optimization design for the hydraulic pressure system with impact vibration practically and effectively,and enhance the quantitative research on the reliability design of hydraulic pipeline *** proposed method has generality for the reliability optimization design of hydraulic pipeline system.

关键词： hydraulic pressure impact vibration systems probability perturbation method reliability design

Digitalized Accurate Modeling of SPCB with Multi-spiral Surface Based on CPC Algorithm

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Chinese Journal of mechanical Engineering 2015年第5期28卷 1039-1047页

作者： HUANG Yanhua GU Lizhi college of mechanical Engineering and Automation Huaqiao University

The main methods of the existing multi-spiral surface geometry modeling include spatial analytic geometry algorithms, graphical method, interpolation and approximation algorithms. However, there are some shortcomings in these modeling methods, such as large amount of calculation, complex process, visible errors, and so on. The above methods have, to some extent, restricted the design and manufacture of the premium and high-precision products with spiral surface considerably. This paper introduces the concepts of the spatially parallel coupling with multi-spiral surface and spatially parallel coupling body. The typical geometry and topological features of each spiral surface forming the multi-spiral surface body are determined, by using the extraction principle of datum point cluster, the algorithm of coupling point cluster by removing singular point, and the ＂spatially parallel coupling＂ principle based on the non-uniform B-spline for each spiral surface. The orientation and quantitative relationships of datum point cluster and coupling point cluster in Euclidean space are determined accurately and in digital description and expression, coupling coalescence of the surfaces with multi-coupling point clusters under the Pro/E environment. The digitally accurate modeling of spatially parallel coupling body with multi-spiral surface is realized. The smooth and fairing processing is done to the three-blade end-milling cutter＇s end section area by applying the principle of spatially parallel coupling with multi-spiral surface, and the alternative entity model is processed in the four axis machining center after the end mill is disposed. And the algorithm is verified and then applied effectively to the transition area among the multi-spiral surface. The proposed model and algorithms may be used in design and manufacture of the multi-spiral surface body products, as well as in solving essentially the problems of considerable modeling errors in computer graphics and engineeri

关键词： coupling point cluster algorithm topological features multi-spiral surface coupling spatially parallel coupling body datum point cluster

Global optimization for ducted coaxial-rotors aircraft based on Kriging model and improved particle swarm optimization algorithm

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Journal of Central South University 2015年第4期22卷 1315-1323页

作者：杨璐鸿刘顺安张冠宇王春雪 college of mechanical Science and Engineering Jilin University

To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example and Fluent software was applied to the virtual prototype simulations. Through simulation sample points, the total lift of the ducted coaxial-rotors aircraft was obtained. The Kriging model was then constructed, and the function was fitted. Improved particle swarm optimization(PSO) was also utilized for the global optimization of the Kriging model of the ducted coaxial-rotors aircraft for the determination of optimized global coordinates. Finally, the optimized results were simulated by Fluent. The results show that the Kriging model and the improved PSO algorithm significantly improve the lift performance of ducted coaxial-rotors aircraft and computer operational efficiency.

关键词： ducted coaxial rotors aircraft Kriging model particle swarm optimization global optimization

Interaction between a screw dislocation and a circular nano-inhomogeneity with a bimaterial interface

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Acta Mechanica Solida Sinica 2017年第1期30卷 39-50页

作者： Tengwu He Wanshen Xiao Xiangdong Li Yan Zhang college of mechanical and Vehicle Engineering Hunan University

The problem of a screw dislocation interacting with a circular nano-inhomogeneity near a bimaterial interface is investigated. The stress boundary condition at the interface between the inhomogeneity and the matrix is modified by incorporating surface/interface stress. The analytical solutions to the problem in explicit series are obtained by an efficient complex variable method associated with the conformal mapping function. The image force exerted on the screw dislocation is also derived using the generalized Peach–Koehler formula. The results indicate that the elastic interference of the screw dislocation and the nano-inhomogeneity is strongly affected by a combination of material elastic dissimilarity, the radius of the inclusion, the distance from the center of inclusion to the bimaterial interface, and the surface/interface stress between the inclusion and the matrix. Additionally, it is found that when the inclusion and Material 3 are both harder than the matrix（ μ1 〉 μ2 and μ3 〉 μ2）, a new stable equilibrium position for the screw dislocation in the matrix appears near the bimaterial interface; when the inclusion and Material 3 are both softer than the matrix（ μ1 〈 μ2 and μ3 〈 μ2）, a new unstable equilibrium position exists close to the bimaterial interface.

关键词： Screw dislocation Image force Conformal mapping Bimaterial interface Nano-inhomogeneity

Preparation of hollow ceramic microspheres absorbent based on self-reactive quenching technology

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Rare Metals 2015年第5期34卷 344-350页

作者： Jian-Jiang Wang Hong-Fei Lou Jin-Hua Wen Xu-Dong Cai Advanced Materials Institute Mechanical Engineering College

A1 ＋ BaO2 ＋ Fe2O3 ＋ sucrose and O2 as reaction system and feeding gas, respectively, are used to prepare hollow multiphase ceramic microspheres （HMCMs） absorbent based on self-reactive quenching technology. The morphologies, particle size distribution, hollow structure and phase compositions were characterized by scanning electron microscope （SEM）, X-ray diffraction （XRD） and size analysis. The results show that the quenching products possess high sphere-forming rate, and most of them are hollow structures. Owing to the self-burst, the particle size is between 40 and 70 μm. The phase compositions contain Al2O3, Fe3O4, Fe2O3, Ba2Fe14O22, BaO2 and BaFe4O7. The microwave absorbing tests show that the lowest reflectivity of HMCMs is -19 dB. The frequency bands less than -10 dB are from 13.0 to 15.8 GHz. The reasons for HMCMs possessing good microwave absorbing properties may be their magnetic and electrical properties as well as special hollow structure.

关键词： Self-reactive quenching technology Hollow multiphase ceramic microspheres Microwave absorbing properties

Geometric Condition of 3UPS-S Parallel Mechanism in Singular Configuration

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Chinese Journal of mechanical Engineering 2014年第1期27卷 130-137页

作者： HAN Xianguo LIU Yanlong college of mechanical Engineering and Automation Beihang University

The existing researches on singularity of parallel mechanism are mostly limited to the property and regularity of singularity locus and there is no further research into the geometric relationship between uncontrolled kinematic screw and parallel mechanism in singularity. A 3UPS-S parallel mechanism is presented which fulfils 3-DOF in rotation. The regularity of nutation angle singularity is analyzed based on the Jacobian matrix, and the singularity surface of 3UPS-S parallel mechanisms is obtained. By applying the concept of reciprocal product in screw theory, the singular kinematic screw is derived when 3UPS-S parallel mechanism is in singularity. The geometric relationship between singular kinematic screw and singular configuration of 3UPS-S parallel mechanism is investigated by using programs in MATLAB. It is revealed that there are two kinds of situation. Firstly, the three limbs of 3UPS-S parallel mechanism intersect the singular kinematic screw in space simultaneously; Secondly, two limbs cross the singular kinematic screw while the third limb parallels with that screw. It is concluded that the nutation angle singularity of 3UPS-S parallel mechanism belongs to the singular linear complexes. This paper sheds light into and clarifies the geometric relationship between singular kinematic screw and singular configuration of 3UPS-S parallel mechanism.

关键词： parallel mechanism condition number of Jacobian matrix screw theory singular linear complexes

Entrance and Exit Defects During Coarse Pitch Orbital Drilling of Carbon Fiber Reinforced Plastic Plates

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第6期33卷 -页

作者： Shan Yicai He Ning Li Liang Zhang Ting college of mechanical and Electrical Engineering Nanjing College of Information Technology college of mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics School of mechanical Engineering Nanjing Institute of Technology

Formation of entrance and exit defects in coarse pitch orbital drilling(CPOD)of carbon fiber reinforced plastic(CFRP)plates was *** observation on entrance and exit morphology shows tear and burr are typical ***,tear is more obvious than burr,and more entrance tears emerge than exit *** one of the major causes of entrance and exit defects in CPOD,cutting forces were substaintially studied by contrast ***,the effect of cutting parameters on entrance and exit tear was qualitatively analyzed through a single factor *** results indicate that the variation of rotation speed has little influence on entrance and exit *** tangential feed per tooth can enlarge entrance tear,but bring little effect on exit *** increasing axial feed pitch,the hole entrance and exit show severe *** revolution radius grows bigger and bigger,entrance and exit tear firstly decreases,and then ***,the models of tear and delamination during CPOD of CFRP were established,the formation mechanisms of entrance and exit defects were revealed,and the control strategies were accordingly put forward.

关键词： carbon fiber reinforced plastics(CFRP) coarse pitch orbital drilling(CPOD) entrance and exit defects formation mechanism

Gradient‑Layered MXene/Hollow Lignin Nanospheres Architecture Design for Flexible and Stretchable Supercapacitors

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Nano-Micro Letters 2025年第2期17卷 447-462页

作者： Haonan Zhang Cheng Hao Tongtong Fu Dian Yu Jane Howe Kaiwen Chen Ning Yan Hao Ren Huamin Zhai Jiangsu Provincial Key Lab of Sustainable Pulp and Paper Technology and Biomass Materials NanJing Forestry UniversityNanjing 210037People’s Republic of China Department of Chemical Engineering and Applied Chemistry University of Toronto200 College StreetTorontoON M5S 3E5Canada Department of Materials Science and Engineering University of Toronto184 College StreetTorontoON M5S 3E4Canada college of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037People’s Republic of China

With the rapid development of flexible wearable electronics,the demand for stretchable energy storage devices has *** this work,a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres(HLNPs)-intercalated two-dimensional transition metal carbide(Ti_(3)C_(2)T_(x) MXene)for fabricating highly stretchable and durable *** depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient,a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene ***,the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility,thus better utilizing the pseudocapacitive property of *** these strategies effectively enhanced the capacitive performance of the *** addition,HLNPs,which acted as a protective phase for MXene layer,enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the *** electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600%uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm^(−2)(241 F g^(−1))and 514 mF cm^(−2)(95 F g^(−1)),***,their capacitances were well preserved after 1000 times of 600%stretch-release *** study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.

关键词： Hollow lignin nanospheres MXene Gradient-layered architecture Wrinkled electrodes Stretchable supercapacitors

Global bifurcations and multi-pulse chaotic dynamics of rectangular thin plate with one-to-one internal resonance

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Applied Mathematics and Mechanics(English Edition) 2012年第9期33卷 1115-1128页

作者：李双宝张伟 college of Science Civil Aviation University of China college of mechanical Engineering Beijing University of Technology

Global bifurcations and multi-pulse chaotic dynamics for a simply supported rectangular thin plate are studied by the extended Melnikov method. The rectangular thin plate is subject to transversal and in-plane excitation. A two-degree-of-freedom nonlinear nonautonomous system governing equations of motion for the rectangular thin plate is derived by the von Karman type equation and the Galerkin approach. A one-to- one internal resonance is considered. An averaged equation is obtained with a multi-scale method. After transforming the averaged equation into a standard form, the extended Melnikov method is used to show the existence of multi-pulse chaotic dynamics, which can be used to explain the mechanism of modal interactions of thin plates. A method for calculating the Melnikov function is given without an explicit analytical expression of homoclinic orbits. Furthermore, restrictions on the damping, excitation, and detuning parameters are obtained, under which the multi-pulse chaotic dynamics is expected. The results of numerical simulations are also given to indicate the existence of small amplitude multi-pulse chaotic responses for the rectangular thin plate.

关键词： rectangular thin plate global bifurcation multi-pulse chaotic dynamics extended Melnikov method