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Acta Mechanica Sinica 1990年第4期6卷 324-332页

作者： Hwang Kehchih Sun Qingping Yu Shouwen (Department of Engineering Mechanics,Tsinghua University,Beijing,China.) 1. Department of Engineering Mechanics Tsinghua University Beijing China

A micromechanics constitutive theory which takes into account both the dilatation and shear ef- fects of the transformation is proposed to describe the macroscopic plastic behavior of structure ceramics during forward transformation under different *** some basic assumptions,the analytic expressions of the Helmholtz and complementary free energy of the constitutive element are derived in a self-consistent manner by using the Mori-Tanaka's method which takes into account the interaction between the transformed *** the framework of Hill-Rice's internal variable constitutive theory,the forward transformation yield function and incremental stress strain relations,in analogy to the theory of metal plasticity,for non-proportional loading histories are obtained.

关键词： shear effect internal variables constitutive element

Influence of shear effects on the Characteristics of Axisymmetric Wave Propagation in a Buried Fluid‑Filled Pipe

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Chinese Journal of Mechanical Engineering 2022年第3期35卷 275-284页

作者： Ping Lu Xiaozhen Sheng Yan Gao Ruichen Wang State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai 201620China Key Laboratory of Noise and Vibration Research Institute of AcousticsChinese Academy of SciencesBeijing 100190China Institute of Railway Research University of HuddersfieldHuddersfield HD13DHUK

The acoustic propagation characteristics of axisymmetric waves have been widely used in leak detection of fluid-filled *** related acoustic methods and equipment are gradually coming to the market,but their theoretical research obviously lags behind the field practice,which seriously restricts the breakthrough and innovation of this *** on the fully three-dimensional effect of the surrounding medium,a coupled motion equation of axisymmetric wave of buried liquid-filled pipes is derived in detail,a contact coefficient is used to express the coupling strength between surrounding medium and pipe,then,a general equation of motion was derived which contain the pipe soil lubrication contact,pipe soil compact contact and pipe in water and ***,the corresponding numerical calculation model is established and solved used numerical *** shear effects of the surrounding medium and the shear effects at the interface between surrounding medium and pipe are discussed in *** output indicates that the surrounding medium is to add mass to the pipe wall,but the shear effect is to add *** the consideration of the contact strength between the pipe and the medium,the additional mass and the pipe wall will resonate at a specific frequency,resulting in a significant increase in the radiation wave to the surrounding *** research contents have great guiding effect on the theory of acoustic wave propagation and the engineering application of leak detection technology in the buried pipe.

关键词： Buried fluid-filled pipe Axisymmetric waves shear effect Dispersion

shear effects in Shakedown Analysis of Offshore Structures

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Journal of Ocean University of China 2008年第2期7卷 177-183页

作者： M. J. Fadaee H. Saffari R. Tabatabaei Civil Engineering Department University of Kerman Po Box 76169-133 Kerman Iran

In this paper, a formulation for shakedown analysis of elastic-plastic offshore structures under cyclic wave loading is presented. In this formulation, a fast numerical solution method is used, suitable for the Finite Element Method (FEM) analysis of large offshore structures on which shear effects in addition to bending and axial effects are taken into account. The Morison equation is adopted for converting the velocity and acceleration terms into resultant forces and it is extended to consider arbitrary orientations of the structural members. The theoretical methods of the shakedown analysis are discussed in detail and the formulation is applied to an offshore structure to verify the concept employed and its analytical capabilities.

关键词： shear effect shakedown multiplier Melan's theorem Morison equation

Impingement capability of high-pressure submerged water jet: Numerical prediction and experimental verification

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Journal of Central South University 2015年第10期22卷 3712-3721页

作者：刘海霞邵启明康灿龚辰 School of Material Science and Engineering Jiangsu University School of Energy and Power Engineering Jiangsu University

At jet pressures ranging from 80 to 120 MPa, submerged water jets are investigated by numerical simulation and experiment. Numerical simulation enables a systematic analysis of major flow parameters such as jet velocity, turbulent kinetic energy as well as void fraction of cavitation. Experiments facilitate an objective assessment of surface morphology, micro hardness and surface roughness of the impinged samples. A comparison is implemented between submerged and non-submerged water jets. The results show that submerged water jet is characterized by low velocity magnitudes relative to non-submerged water jet at the same jet pressure. shear effect serves as a key factor underlying the inception of cavitation in submerged water jet stream. Predicted annular shape of cavity zone is substantiated by local height distributions associated with experimentally obtained footprints. As jet pressure increases, joint contribution of jet kinetic energy and cavitation is demonstrated. While for non-submerged water jet, impingement force stems exclusively from flow velocity.

关键词： submerged water jet cavitation shear effect impingement test micro hardness surface morphology

Mechanism of nanoparticle aggregation in gas-liquid microfluidic mixing

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Chinese Chemical Letters 2024年第4期35卷 376-381页

作者： Hongxia Li Xiyang Wang Du Qiao Jiahao Li Weiping Zhu Honglin Li Key Laboratory for Precision&Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116023China Shanghai Key Laboratory of New Drug Design School of PharmacyEast China University of Science and TechnologyShanghai 200237China

Using gas-liquid segmented micromixers to prepare nanoparticles that have a homogeneous particle size, controllable shape, and monodispersity advantages. Although nanoparticle aggregation within a microfluid has been shown to be affected by the shear effect, the shear effect triggering conditions in gasliquid two-phase flow is unclear and the aggregation behavior of nanoparticles under the shear effect is difficult to predict, resulting in uncontrollable physical and chemical properties of nanoparticle aggregates. In this study, a numerical simulation of nanoparticle aggregation in gas-liquid two-phase flow under the shear effect is performed using the CFD-DEM method. Then, the effects of total flow rate,gas-liquid two-phase flow ratio, and particle volume fraction on particle aggregation were analyzed to achieve control of particle aggregation shape and size. Meanwhile, the triggering mechanism of the shear effect and the mechanism of the shear effect on the aggregation of nanoparticles were clarified. The results show that increasing the total flow rate or decreasing the gas-liquid two-phase flow rate ratio can induce the shear effect, which reduces the particle aggregation size and makes the morphology tend to be spherical. Moreover, increasing the particle volume fraction, and total flow rate or decreasing the gas-liquid two-phase flow rate ratio also increases the number of particle collisions and induce interparticle adhesion. Hence, particle adhesion and the shear effect compete with each other and together affect particle aggregation.

关键词： Microfluidic Gas-liquid segmented micromixer Nanoparticle aggregation shear effect Numerical calculation

ASYMPTOTIC ANALYSIS OF PLANE-STRAIN MODE I STEADY-STATE CRACK GROWTH IN TRANSFORMATION TOUGHENINGCERAMICS(Ⅱ)

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Applied Mathematics and Mechanics(English Edition) 1997年第7期18卷 689-696页

作者：张浠叶裕恭 Zhongnan Institute of Technology 421001 Hengyang P. R. China Institute of Mechanics Chinese Academy of Sciences 100080 Beijing P. R. China

Based on a constitutive law which includes the shear components oftransformation plasticity. the asymptotic solutions to near-tip fields of plane-strainmode I steadity propagating cracks in rransformed ceramics are obtained for the caseof linear isotropic hardening. The Stress singularity. the distributions of stresses andvelocities at the crack tip are determmed for various material parameters. The factorsinfluencing the near-tip fields are discussed in detail.

关键词： transformation toughening ceramics shear effect crack growth,asymptotic method

Hydrodynamic shear Stress Affects Cell Growth and Metabolite Production by Medicinal Mushroom Ganoderma lucidum

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Chinese Journal of Chemical Engineering 2005年第3期13卷 426-428页

作者：龚海刚钟建江 State Key Laboratory of Bioreactor EngineeringEast China University of Science and Technology Shanghai 200237China

By investigating the shear effect on submerged cultivation of a traditional Chinese medicinal herb Ganoderma lucidum, a relatively high cell concentration of 13.8 g·L-1 by dry mass was obtained in bioreactor at an impeller tip speed (ITS) of 0.51m·s-1. At an ITS of 0.51,1.02 and 1.53m·s-1, a maximal production titer of intracellular polysaccharide was 2.64, 2.20 and 2.28g·L-1 and that of ganoderic acid was 306, 299 and 273g·L-1, respectively. Under these ITSs, the maximal mean projected area of dispersed hyphae was 3.70, 2.54 and 2.13×104μm2, and that of pellets was 0.91, 0.67 and 0.55mm2, respectively. The information obtained is useful for efficient submerged cultivation of mushrooms on a large scale.

关键词： Ganoderma lucidum mushroom cultures shear effect Ganoderma polysaccharide ganoderic acid bioreactor