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Journal of Bionic Engineering 2009年第2期6卷 143-152页

作者： x.q.kong C W Wu State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of Technology

Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, named fascicle. Here the structure of the Aedes albopictus mosquito fascicle is obtained using a Scanning Electron Microscope (SEM), and the whole process of the fascicle inserting into human skin is observed using a high-speed video imaging technique. Direct measurements of the insertion force for mosquito fascicle to penetrate into human skin are reported. Results show that the mosquito uses a very low force (average 18 μN) to penetrate into the skin. This force is at least three orders of magnitude smaller than the reported lowest insertion force for an artificial microneedle with an ultra sharp tip to insert into the human skin. In order to understand the piercing mechanism of mosquito fascicle tip into human multilayer skin tissue, a numerical simulation is conducted to analyze the insertion process using a nonlinear finite element method. A good agreement occurs between the numerical results and the experimental measurements.

关键词： biomimetic microneedle mosquito fascicle mechanics penetration

The Novel Mechanical Property of Tongue of a Woodpecker

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Journal of Bionic Engineering 2009年第3期6卷 214-218页

作者： P Zhou x.q.kong C W Wu Z Chen National Key Laboratory for Structural Analysis of Industrial Equipment Dalian University of Technology Department of Civil and Environmental Engineering University of Missouri

Biomaterials such as bone,teeth,nacre and silk are known to have superior mechanical properties due to their specific nanocomposite *** we report that the woodpecker's tongue exhibits a novel strength and flexibility due to its special composite micro/*** tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue of high strength and *** the interface between the cartilage-and-bone skeleton and the tissue layer,there is a hierarchical fiber-typed *** is this special design of the tongue that makes the woodpeckers efficient in catching the insects inside *** special micro/nanostructures of the woodpecker's tongue show us a potential method to enhance the interfacial connection between soft and hard material layers for bio-inspired composite system designs.

关键词： woodpeckcr hyoid cartllage multilevel structure tensile strength

Modified spherical cavity-expansion model for projectile penetration into concrete targets

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Acta Mechanica Sinica 2019年第3期35卷 518-534页

作者： Y.Peng H.Wu q.Fang x.Z.kong College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai 200092China State Key Laboratory for Disaster Prevention and Mitigation of Explosion and Impact PLA Amy Engineering UniversityNanjing 210007China

A modified spherical cavity-expansion model is developed in this paper.(1) We introduce a piecewise hyperbolic yield criterion suitable for pressure less than fc/3 to describe the mechanical behavior in the elastic region for the elastic-plastic response and modify the crack occurrence condition for the elastic-cracked-plastic response.(2) The hyperbolic yield criterion and a piecewise equation of state (EOS) are adopted for a better description of the plastic behavior of concrete material. Then, the modified model is validated by several projectile penetration tests in both the normal strength concrete (NSC) and ultra-high performance cement-based composite (UHPCC) targets. Finally, the hydrostatic pressure of the targets under rigid ogive-nosed projectile penetrations is found to be nearly within (0, 1.6 GPa), which usually exceeds the range that the shear strength-pressure test data covered. The influence of yield criterion on depth of penetration is discussed and it is recommended that the pressure should arrive at least 400 MPa in the related triaxial compression tests.

关键词： Dynamic cavity-expansion model Projectile Penetration Concrete Depth of penetration

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

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Acta Mechanica Sinica 2015年第4期31卷 558-569页

作者： H.Wu x.W.Chen q.Fang x.Z.kong L.L.He Institute of Systems Engineering China Academy of Engineering Physics State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force Law （DAFL） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

Golden Ratio-Based and Tapered Diptera Inspired Wings： Their Design and Fabrication Using Standard MEMS Technology

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Journal of Bionic Engineering 2011年第2期8卷 174-180页

作者： x. q. Bao IEMN CNRS UMR 8520 F-59650 Villeneuve d Ascq France UVHC IEMN F-59313 Valenciennes France SIMIT Chinese Academy of Sciences Shanghai 200050 P. R. China

This work presents our understanding of insect wings, and the design and micromachining of artificial wings with golden ratio-based and tapered veins. The geometric anisotwpy of Leading Edge Veins （LEVs） selected by Diptera has a function able to evade impact. As a Diptera example, the elliptic hollow-LEVs of cranefly wings are mechanically and aerodynamically significant. In this paper, an artificial wing was designed to be a fractal structure by mimicking cranefly wings and incorporating cross-veins and discal cell. Standard technologies of Microelectromechanical Systems （MEMS） were employed to materialize the design using the selected material. One SU-8 wing sample, light and stiffenough to be comparable to fresh cranefly wings, was presented. The as-prepared SU-8 wings are faithful to real wings not only in weight and vein pattern, but also in flexural stiffness and mass distribution. Thus our method renders possible mimickine with good lidelity of natural wings with complex geometry and morphology.

关键词： insect inspired wing SU-8 MEMS flcxural stiffness Diptera

ExPERIMENTS OF HYDRODYNAMICS AND STABILITY OF IMMERSED TUBE TUNNEL ON TRANSPORTATION AND IMMERSING

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Journal of Hydrodynamics 2001年第2期13卷 121-126页

作者： Zhan, D.x. Wang, x.q. Dept. of Naval Arch. and Ocean Eng. Wuhan Univ. of Technol. Wuhan 430063 China

Effects of environment conditions, such as current, wave etc., are more important for immersed tube tunnel's transportation and immersing. The hydrodynamics and stability of immersed tube tunnel during its towing and immersing are interested for departments of design and construction. A serial model tests are made in towing tank and water channel for Nanjing immersed tube tunnel, and the first immersed tunnel has been designed in Yangtzi River in China. The hydrodynamic forces and rope tensions of the tunnel are measured with strain balances when it is towed by ship and immersed by winches for a different current velocity and wave height. In addition, the stability of tunnel for a different ballast water is tested and discussed.

关键词： Hydrodynamics Stability Tensile testing Test facilities

Reducing the anisotropy of a Brazilian disc generated in a bonded-particle model

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Acta Mechanica Sinica 2018年第4期34卷 716-727页

作者： q.Zhang x.P.Zhang P.q.Ji The Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province School of Civil EngineeringWuhan University

The Brazilian test is a widely used method for determining the tensile strength of rocks and for calibrating parameters in bondedparticle models（BPMs）. In previous studies, the Brazilian disc has typically been trimmed from a compacted rectangular specimen. The present study shows that different tensile strength values are obtained depending on the compressive loading direction. Several measures are proposed to reduce the anisotropy of the disc. The results reveal that the anisotropy of the disc is significantly influenced by the compactibility of the specimen from which it is trimmed. A new method is proposed in which the Brazilian disc is directly generated with a particle boundary, effectively reducing the anisotropy. The stiffness（particle and bond） and strength（bond） of the boundary are set at less than and greater than those of the disc assembly, respectively,which significantly decreases the stress concentration at the boundary contacts and prevents breakage of the boundary particle bonds. This leads to a significant reduction in the anisotropy of the disc and the discreteness of the tensile strength. This method is more suitable for carrying out a realistic Brazilian test for homogeneous rock-like material in the BPM.

关键词： Bonded-particle model Brazilian disc Anisotropy Compactibility Particle boundary

Fluid-structure interaction in Z-shaped pipe with different supports

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Acta Mechanica Sinica 2020年第2期36卷 513-523页

作者： q.Guo J.x.Zhou x.L.Guan College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Highway Science and Technology Research Institute Xinjiang Production and Construction Corpsürümqi 830002China

Fluid-structure interaction(FSI)has a strong relation with layout of fluid delivery *** is liable to cause local ***,FSI analysis is necessary in many cases,especially for flexible pipe *** modeling consists of eight governing equations and then completely solved via the finite volume method(FVM).Friction,Poisson and joint couplings were discussed in detail to reveal the influence of a Z-shaped pipe with different supports and elbows on *** the feasibility of solving FSI by FVM was verified,the different effects of free,fixed and elastic supports on FSI in the commonly used and simplified Z-shaped pipe were further *** indicated that different support stiffness lead to various FSI *** coupling occurs at the elbow and less support is considered,then the pipe has a relatively large amplitude and complex pressure fluctuation.

关键词： Fluid-structure interaction Finite volume method Z-shaped pipe Support stiffness

DYNAMIC MODEL AND SIMULATION OF EAF STEELMAKING PROCESS

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Acta Metallurgica Sinica(English Letters) 2003年第3期16卷 197-203页

作者： q.Li x.Hong Shanghai Enhanced Laboratory of Ferrometallurgy Shanghai University Shanghai 200072 ChinaShanghai Enhanced Laboratory of Ferrometallurgy Shanghai University Shanghai 200072 China

Based on mass and energy balances and theories of thermodynamics and kinetics, a dynamic model in conjunction with relative operation parameters was derived. With this model, the EAF process in later stage of scarp melting was dynamically described, including time dependent variations of bath temperature, slag quantity, compositions of steel, slag and off-gas, etc. Steelmaking process in a domestic 100 ton UHP AC EAF was chosen as a computational example, and the simulated variations of temperature of hot metal and element contents was shown consistent with the actual process measurements within average error scopes of |△T| xtended to predict the whole production process including scrap melting procedure and evaluate its energy and material consumption, the production efficiency, etc., which will provide assistance for the improvement of EAF operation and control.

关键词： EAF dynamic model simulation