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Anti-penetration performance of high entropy alloy–ceramic gradient composites

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1320-1328页

作者： Wen-rui Wang Hui-fa Xie Lu Xie Han-lin Li Xiao Yang Yi-nan Shen school of Mechanical Engineering University of Science and Technology Beijing loughborough design school Loughborough University Technical Institute of Physical and Chemistry Chinese Academy of Sciences school of Energy and Environmental Engineering University of Science and Technology Beijing

A high-entropy alloy–ceramic gradient composite of TiC–TiB_2/75vol% Al_(0.3) CoCrFe Ni was successfully prepared by combustion synthesis under an ultra-high gravity field, which is a low-cost method with high efficiency. The ceramic particles were gradient distributed in the Al_(0.3) CoCrFe Ni matrix, and the hardness of the composite material gradually decreased along the thickness direction. The anti-penetration performance of the gradient composites was simulated using the ANSYS/LS-DYNA explicit simulation program. The results demonstrate that the distribution of the ceramic particles strongly affected the mechanical properties and the anti-penetration performance of the composites. With the same total ceramic volume fraction, the gradient composites exhibit better anti-penetration performance than the corresponding ceramic–metal interlayer composites. The more uneven the ceramic distribution, the greater the elastic modulus and yield stress of the surface layer and, thus, the better the anti-penetration performance.

关键词： combustion synthesis gradient composite anti-penetration performance numerical simulation

Structural Modal Parameter Recognition and Related Damage Identification Methods under Environmental Excitations: A Review

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Structural Durability & Health Monitoring 2025年第1期19卷 25-54页

作者： Chao Zhang Shang-Xi Lai Hua-Ping Wang school of Civil Engineering and Mechanics Lanzhou UniversityLanzhou730000China Key Laboratory of Special Functional Materials and Structural design Ministry of EducationLanzhou UniversityLanzhou730000China

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the ***,it is particularly signiﬁcant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientiﬁc basis for structural damage identiﬁcation and dynamic model modiﬁ*** view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and brieﬂy describes how to identify structural damages based on the derived modal *** paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),brieﬂy describes damage identiﬁcation methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artiﬁcial intelligence(AI)methods in the direction of modal parameter recognition and damage identiﬁcation is further *** on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identiﬁcation methods are given to provide scientiﬁc references for the optimized design and functional upgrading of SHM systems.

关键词： Structural health monitoring data information modal parameters damage identiﬁcation AI method

Recursive Filter with Partial Knowledge on Inputs and Outputs

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International Journal of Automation and computing 2015年第1期12卷 35-42页

作者： Jinya Su Baibing Li Wen-Hua Chen Department of Aeronautical and Automotive Engineering Loughborough University school of Business and Economics Loughborough University

This paper investigates the problem of state estimation for discrete-time stochastic linear systems, where additional knowledge on the unknown inputs is available at an aggregate level and the knowledge on the missing measurements can be described by a known stochastic distribution. Firstly, the available knowledge on the unknown inputs and the state equation is used to form the prior distribution of the state vector at each time step. Secondly, to obtain an analytically tractable likelihood function, the effect of missing measurements is broken down into a systematic part and a random part, and the latter is modeled as part of the observation noise. Then, a recursive filter is obtained based on Bayesian inference. Finally, a numerical example is provided to evaluate the performance of the proposed methods.

关键词： Bayesian inference Kalman filter missing measurements state estimation unknown inputs

Robust Assignment of Airport Gates with Operational Safety Constraints

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International Journal of Automation and computing 2016年第1期13卷 31-41页

作者： Shuo Liu Wen-Hua Chen Jiyin Liu Department of Aeronautical and Automotive Engineering Loughborough University school of Business and Economics Loughborough University

This paper reviews existing approaches to the airport gate assignment problem （AGAP） and presents an optimization model for the problem considering operational safety constraints. The main objective is to minimize the dispersion of gate idle time periods （to get robust optimization） while ensuring appropriate matching between the size of each aircraft and its assigned gate type and avoiding the potential hazard caused by gate apron operational conflict. Genetic algorithm is adopted to solve the problem, An illustrative example is given to show the effectiveness and efficiency of the algorithm. The algorithm performance is further demonstrated using data of a terminal from Beijing Capital International Airport （PEK）.

关键词： Gate assignment problem operational safety constraints robust optimization conflict avoidance genetic algorithm.

Studying turbulence structure near the wall in hydrodynamic flows:An approach based on the Schur decomposition of the velocity gradient tensor

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Journal of Hydrodynamics 2022年第5期34卷 806-825页

作者： Christopher J.Keylock school of Architecture Building and Civil EngineeringLoughborough UniversityLeicestershireUK

The Schur decomposition of the velocity gradient tensor(VGT)is an alternative to the classical Cauchy-Stokes decomposition into rotation rate and strain rate ***,there have been several strands of work that have employed this decomposition to examine the physics of turbulence dynamics,including approaches that combine the Schur and Cauchy-Stokes *** are briefly reviewed before the latter approach is set *** partitions the rotation rate and strain rate tensors into normal/local and non-normal/non-local *** then study the relation between the VGT dynamics and ejection-sweep events in a channel flow *** show that the sweeps in particular exhibit novel behaviour compared with either the other quadrants,or the flow in general,with a much-reduced contribution to the dynamics from the non-normal terms above the viscous *** particular,the reduction in the production term that is the interaction between the non-normality and the normal straining reduces in the log-layer as a consequence of an absence of alignment between the non-normal vorticity and the strain rate *** have been early forays into using the Schur transform approach for subgrid-scale modelling in large-eddy simulation(LES)and this would appear to be an exciting way forward.

关键词： Turbulence channel flow velocity gradient tensor Schur decomposition

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin Zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia school of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

In vitro investigation of cellular effects of magnesium and magnesium-calcium alloy corrosion products on skeletal muscle regeneration

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Journal of Materials Science & Technology 2019年第11期35卷 2503-2512页

作者： Diana Maradze Andrew Capel Neil Martin Mark PLewis Yufeng Zheng Yang Liu Centre of Biological Engineering Wolfson School of MechanicalElectrical and Manufacturing EngineeringLoughborough UniversityLoughboroughLeicestershireLE113TUUK school of Sport Exercise and Health SciencesLoughborough UniversityLoughboroughLeicestershireLE113TUUK Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China

Biodegradable magnesium(Mg)has garnered attention for its use in orthopaedic implants due to mechanical properties that closely match to those of *** have been undertaken to understand the corrosion behaviour of these materials and their effects on bone forming ***,there is lack of research on how the corrosion of these biomaterials affect surrounding tissues such as skeletal *** plays an important role in the structural and functional properties of skeletal *** is therefore important to investigate the response of skeletal muscle cells to both soluble(Mg ions)and insoluble(corrosion granules)corrosion *** in vitro studies it is possible to observe the effects of corrosion products on myotube formation by the fusion of single muscle precursor cells known as *** achieve this goal,it is important to determine if these corrosion products are toxic to *** it was noted that although there was a slight decrement in cellular viability after initial exposure,this soon recovered to control levels.A high Ca/Mg ratio resulted in the formation of large myotubes and a low Ca/Mg ratio negatively affected myotube ***^2+and Ca^2+ions are important in the process of myogenesis,and the concentration of these ions and the ratio of the ions to each other played a significant role in myotube cellular *** outcomes of this study could pave the way to a bio-informed and integrated approach to the design and engineering of Mg-based orthopaedic implants.

关键词： Magnesium alloy Corrosion Biocompatibility Muscle Cellular response In vitro

designing Visceral, Behavioural and Reflective Products

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1058-1068页

作者： Mersha Aftab Helen Agustin Rusli Northumbria school of design Northumbria University

designers and manufacturers often see con- sumption as the primary objective of a product - with implications such as discarded products, obsolete wastes, and ecological degradation. The paper aims to find the answer to the question, how emotional design can adapt the discarded and undesirable products into something valu- able in a long term？ This paper presents a framework combining Chapman＇s theory and Norman＇s theory on three levels of emotional design to highlight what long lasting connection with products entails. A design approach is presented combing the Wabi Sabi philosophy that pro- motes the celebration of decay and damage. This is used as one of the design principles for the experiments conducted on discarded products. Through constant user interaction before, during and after the experiments the evaluation of design as an agent of transformation is done. The user conducted the evaluation based on the Kansei elements of looks, sound, smell, and feel of the product. The experi- ments confirmed that a long-term value is only achieved through redesigning and reconstructing the perception of people towards products on a reflective level, rather than the visceral and behavioural elements of the product. The research found attachment to the visceral and behavioural elements of a product instead of an emotional one was causing users to discard products faster than required. The research indicated that many people, including designers and manufacturers, are unconsciously focusing on usability （behavioural level） and physical look （visceral level） of a product that are easily replaced, than on a meaningful way （reflective level） to create and maintain long-lasting emo- tions. The research concluded with a proposition towards digitization of products which could perhaps be an all round solution to make products more appropriate to human emotions. Digitization could give products the ability to capture, store and then communicate the stories, journey and memories b

关键词： Research through design. Emotional design -Kansei design ~ Recycling ~ Upcycling ~ Product design

Inflows/outflows driven particle dynamics in an idealised lake

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Journal of Hydrodynamics 2019年第5期31卷 873-886页

作者： Cheng-hua Dang Jingchun Wang Qiuhua Liang school of Water Conservancy and Hydropower Hebei University of EngineeringHandan 056021China Jeremy Benn Associates Limited ColeshillWarwickshireUK school of Architecture Building and Civil EngineeringLoughborough UniversityLoughboroughUK

This paper considers fluid mixing driven by inflows connected to a circular shallow lake using a numerical framework consisting of a shallow water hydrodynamic model and a passive particle-tracking *** the flow field driven by alternate inflows predicted by a shallow water model,particle trajectories are traced out using a particle tracking *** horizontal fluid mixing dynamics are then interpreted using dynamics system analysis approaches including finite-time Lyapunov exponent(FTLE)and Lagrangian coherent structure(LCS).From the simulation results,it is confirmed that periodic inflows are able to create a weak dynamic system in an idealised circular lake,with the particle dynamics controlled by a single dimensionless parameter associated with the inflow *** mixing and transport property of the lake changes from regular to chaotic as the value of the dimensionless parameter increases until global chaotic particle dynamics is *** further analysing the advection of particles injected continuously to the inflows(freshwater),the fate of“freshwater”particles in a“polluted”lake is tracked and *** results provide useful guidance for engineering applications,i.e.,transferring freshwater from rivers to improve the water quality in polluted water bodies such as *** presented approach will be able to facilitate the design of‘optimised’schemes for such engineering implementation.

关键词： Shallow environmental flow Lagrangian particle dynamics particle tracking inflows and outflows finite-time Lyapunov exponent Lagrangian coherent structure