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Journal of Central South University of Technology 2004年第3期11卷 336-339页

作者：徐庆元周小林曾志平杨小礼 School of Civil Engineering and Architecture Central South University Changsha 410075 China

A new mechanics model, which reveals additional longitudinal force transmission between the continuously welded rails and the bridges, is established on the fact that the influence of the mutual relative displacement (among) the rail, the sleeper and the beam is taken into account. An example is presented and numerical results are compared. The results show that the additional longitudinal forces calculated with the new model are less than those of the previous, especially in the case of the flexible pier bridges. The new model is also suitable for the analysis of the additional longitudinal force transmission between rails and bridges of ballastless track with small resistance fasteners without taking the sleeper displacement into account, and compared with the ballast bridges, the ballastless bridges have a much stronger additional longitudinal force transmission between the continuously welded rails and the bridges.

关键词： railway engineering continuously welded rails on bridge additional longitudinal force mechanics model

mechanics model to Determine Swelling Potential of Expansive Soils

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Journal of Harbin Institute of Technology(New Series) 2004年第2期11卷 125-128页

作者：区马张克绪 School of Civil Engineering Harbin Institute of Technnlogy Harbin 150090 China School of Civil Engineering Harbin Institute of Technnlogy Harbin 150090 Chinahe factors influencing on soil expansion are reviewed in the paper. A mechanics model to determine swelling potential of expansive soils is presented. The mechanics model is based on the softening of expansive soil following absorption of water. The constitutive relationships of the mechanics model include the relationship among swelling under free load swelling under load and vertical pressure and the relationship of swelling under free loading and swelling pressure. A concept of additional compression modulus is introduced and the method determining the modulus is proposed. Finally the predicted results of swelling potential using the mechanics model compare well with the measured data.

The factors influencing on soil expansion are reviewed in the paper. A mechanics model to determine swelling potential of expansive soils is presented. The mechanics model is based on the softening of expansive soil following absorption of water. The constitutive relationships of the mechanics model include the relationship among swelling under free load, swelling under load, and vertical pressure, and the relationship of swelling under free loading and swelling pressure. A concept of additional compression modulus is introduced and the method determining the modulus is proposed. Finally, the predicted results of swelling potential using the mechanics model compare well with the measured data.

关键词： expansive soils swelling potential softening mechanics model additional compression modulus

NONLINEAR MOTION mechanics model OF CURVED BLOOD VESSEL

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Acta Mechanica Solida Sinica 2003年第1期16卷 67-73页

作者： Qiao Aike Liu Youjun Wu Shigui Xu Xiaohu Zeng Yanjun Medical School Shantou UniversityShantou 515031China College of Mechanical Engineering Beijing University of TechnologyBeijing 100022China

A geometric model of curved blood vessels is established based on some reasonable hypotheses; the nonlinear motion mechanics model of the curved blood vessel is established according to basic mechanics laws. This model includes much more physiological factors. It couples the interaction of blood flow with mechanical factors such as the displacement, deformation, strain and stress etc. of the curved blood vessel. It is of great importance for investigating the circulation rules of the cardiovascular system and the nonlinear pulse wave propagation in curved blood vessels.

关键词： curved blood vessel motion equation mechanics model pulse wave propagation

Metal-soil interface adhesion in clay clogging during shield tunneling:Theoretical model and experimental validation

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Underground Space 2024年第2期15卷 188-202页

作者： Yong Fang Bin Zhuo Yubo Wang Hu Luo Junfeng Sun Yuxiang Yao Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging is a major geohazards risk in mechanized tunnelling through cohesive *** clogging results from the high adhesion between the clay and *** on the water film theory and Reynolds fluid equation,the interfacial adhesion between metal and soil is simplified in this study as viscous hydrodynamic behavior between *** the influence of capillary force and the viscous force of water film at the interface between metal and soil,a theoretical calculation model of interfacial adhesion between metal and soil is *** influence of water film thickness and separation rate on the interfacial adhesion between metal and soil is qualitatively ***,the adhesion stress between the clay and the metal surface was tested with a pullout test and the influence of moisture content,pullout rates and types of clay minerals on the adhesion stress was ***,the calculation model of adhesion force was compared with the experimental *** calculation model of soil adhesion stress established in this paper can quantitatively describe the relationship between soil adhesion force and moisture content and can also qualitatively reveal the influence mechanism of soil moisture content on adhesion stress.

关键词： EPB clogging Adhesion stress mechanics model Clays Mechanism analysis Experimental test

modeling and adaptive motion/force tracking for vertical wheel on rotating table

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Journal of Systems Engineering and Electronics 2015年第5期26卷 1060-1069页

作者： Zhongcai Zhang Yuqiang Wu Wei Sun School of Automation Southeast University Institute of Automation Qufu Normal University

This paper is devoted to the problem of modeling and adaptive motion/force tracking for a class of nonholonomic dynamic systems with affine constraints(NDSAC): a vertical wheel on a rotating table. Prior to the development of tracking controller,the dynamic model of the wheel in question is derived in a meticulous manner. A continuously differentiable friction model is also considered in the modeling. By exploiting the inherent cascade interconnected structure of the wheel dynamics, an adaptive motion/force tracking controller is presented guaranteeing that the trajectory tracking errors asymptotically converge to zero while the contact force tracking errors can be made small enough by tuning design parameters. Simulation results are provided to validate the effectiveness of the proposed tracking methodology.

关键词： nonholonomic system adaptive motion/force tracking mechanics model affine constraint

ON THE mechanics OF INTEGRIN CLUSTERING DURING CELL-SUBSTRATE ADHESION

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Acta Mechanica Solida Sinica 2012年第5期25卷 467-472页

作者： Hongyan Yuan Huajian Gao School of Engineering Brown University Providence RI 02912 USA

Recent numerical simulations have indicated that integrin clustering during cell- substrate adhesion can be driven by the presence of a repulsive layer between the cell membrane and the substrate （Paszek et al., PLoS Comput Biol 5：12, 2009）. Here we present a simple me- chanics model of this phenomenon in which the attraction between integrins is mediated by the long-range elastic deformation of the membrane and the repulsive layer. We obtain analytical solutions to the problem by employing the small deformation theory of an infinitely extended plate resting on an elastic foundation.

关键词： integrin clustering mechanics model cell-substrate adhesion attractive interaction

MODULUS-COMPOSITION DEPENDENCE FOR BLENDS OF PVC WITH SEGMENTED POLYURETHANES OF DIFFERENT SOFT SEGMENTS

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Chinese Journal of Polymer Science 1991年第1期9卷 55-64页

作者：肖凤飞施良和徐懋 Polymer Physics Laboratory Institute of Chemistry Academia Sinica

The dynamic mechanical modulus at 25℃ for blends of segmented polyurethanes with PVC was studied by using suitable mechanics models of multi-component systems. The analysis indicates that the blend morphology was mainly determined by soft segment structure of polyurethanes. The PPO-PU/PVC blends show typical two-phase morphology and their modulus-composition relations may be described by Halpin-Tsai model for domain-matrix two-phase *** the PCL-PU / PVC, PTMA-PU/PVC and PTMO-PU/PVC blends fit the Kerner's packed grain composite model. These results may imply that the modulus-composition relationship is sensitive to the interactions between the components and the mixture morphology of the blends.

关键词： Blends Modulus mechanics model PVC : Segmented polyurethane.

modeling and adaptive motion/force tracking for vertical wheel on rotating table

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Journal of Systems Science & Complexity 2015年第5期28卷 1060-1069页

作者： Zhongcai Zhang Yuqiang Wu Wei Sun School of Automation Southeast University Institute of Automation Qufu Normal University

关键词： nonholonomic system adaptive motion/force tracking mechanics model affine constraint.

Viscoelastic model for asphalt mixture under repeated haversine load

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Journal of Southeast University(English Edition) 2009年第4期25卷 523-526页

作者：张久鹏黄晓明长安大学特殊地区公路工程教育部重点实验室西安710064 东南大学交通学院南京210096

The series-wound dashpot of the Burgers model is modified by introducing the strain hardening parameter, and the new model is considered as a combination of the modified dashpot and the Van Der Poel model. The cyclical pulse load consisting of a haversine load time and a rest period is adopted to simulate the actual vehicle load, and the permanent strain model under the repeated load is derived from the rheological and viscoelastic theories. Subsequently, the model is validated by the results of uniaxial repeated load permanent deformation tests of three asphalt mixtures. It is indicated that the proportion of residual viscoelastic strain to permanent strain decreases gradually with the load cycles, and only accounts for 2% to 3% during most of the loading period. If the rest period is long, the residual viscoelastic strain is little. The rest period of the actual vehicle load may be long enough, so the residual viscoelasticity can be ignored and the simplified model can be obtained. The proposed model can well describe the permanent deformation of asphalt mixtures under repeated load.

关键词： asphalt mixture permanent deformation mechanics model repeated haversine load