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One-dimensional nonlinear consolidation of soft clay with the non-Darcian flow

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2013年第6期14卷 435-446页

作者： Chuan-xun LI Kang-he XIE Faculty of Civil engineering and mechanics Jiangsu University Research Center of Coastal and Urban Geotechnical engineering Zhejiang University

Based on the non-Darcian flow law described by exponent m and threshold gradient i 1 under a low hydraulic gradient and the classical nonlinear relationships e-lgσ′ and e-lgk v (Mesri and Rokhsar, 1974), the governing equation of 1D nonlinear consolidation was modified by considering both uniform distribution of self-weight stress and linear increment of self-weight stress. The numerical solutions for the governing equation were derived by the finite difference method (FDM). Moreover, the solutions were verified by comparing the numerical results with those by analytical method under a specific case. Finally, consolidation behavior under different parameters was investigated, and the results show that the rate of 1D nonlinear consolidation will slow down when the non-Darcian flow law is considered. The consolidation rate with linear increment of self-weight stress is faster than that with uniform distribution one. Compared to Darcy's flow law, the influence of parameters describing non-linearity of soft soil on consolidation behavior with non-Darcian flow has no significant change.

关键词： Non-Darcian flow Nonlinear consolidation Time-dependent loading Uniform distribution of self-weight stress Linear increment of self-weight stress

A low frequency piezoelectric power harvester using a spiral-shaped bimorph

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Science china(Physics,mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1,2.HU Hongping2.& YANG Jiashi3 1. Institute of mechanics and Sensing Technology,Central South University,Changsha 410083,china 2. {2. of mechanics,Huazhong University of Science and Technology,Wuhan 430074,china 3. {2. of engineering mechanics,University of Nebraska,Lincoln,NE 68588-052.,USA 1. Institute of mechanics and Sensing Technology Central South University Changsha 410083 China 2. department of mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. department of engineering {2. University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.

Investigation on extremal and critical characteristics of ignition time for H_2.O_2.combustion system and their applications

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Science china(Technological Sciences) 2009年第5期52卷 1161-1166页

作者： CHEN JianHua1,ZHANG HuiQiang2.LI ZhuoYi2.& ZHANG GuiTian1 1 School of Aerospace,North Western Polytechnical University,Xi’an 710072.china 2.department of engineering mechanics,Tsinghua University,Beijing 100084,china School of Aerospace North Western Polytechnical University Xi’an 710072 China department of engineering {2. Tsinghua University Beijing 100084 China

The L,H and C curves in P-T phase are proposed to describe the minimal,maximal and critical char-acteristics of ignition time of H2.O2.combustion system,*** features of H2.O2.Air) com-bustion system,including explosion or not as well as the time delay to achieve its explosion status,can be well shown by explosion limits and these proposed *** curves can be described by 1.2.1=ks[Ms],(k11/k10+1)k1=ks[Ms],and 2.1=ks[Ms],respectively,which provide a physical explanation for these curves and give another way to establish *** on the contour of ignition time,the Z-type explosion limits can be explained by thermal explosion ***,the ignition distance of supersonic combustion is predicted according to the ignition time obtained in a Semenov system,which is very reasonable.

关键词： ignition time thermal explosion detailed reaction mechanism Semenov system supersonic combustion

The complex variable reproducing kernel particle method for elasto-plasticity problems

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Science china(Physics,mechanics & Astronomy) 2010年第5期53卷 954-965页

作者： CHEN Li1 & CHENG YuMin2.1 department of engineering {2.,Chang’an University,Xi’an 710064,china 2.Shanghai Institute of Applied Mathematics and {2.,Shanghai University,Shanghai 2.0072.china 1. department of engineering {2. Chang’an University Xi’an 710064 China2. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

On the basis of reproducing kernel particle method(RKPM),using complex variable theory,the complex variable reproducing kernel particle method(CVRKPM) is discussed in this *** advantage of the CVRKPM is that the correction function of a two-dimensional problem is formed with one-dimensional basis function when the shape function is *** the CVRKPM is applied to solve two-dimensional elasto-plasticity *** Galerkin weak form is employed to obtain the discretized system equation,the penalty method is used to apply the essential boundary *** then,the CVRKPM for two-dimensional elasto-plasticity problems is formed,the corresponding formulae are obtained,and the Newton-Raphson method is used in the numerical *** numerical examples are given to show that this method in this paper is effective for elasto-plasticity analysis.

关键词： meshless method reproducing kernel particle method(RKPM) complex variable reproducing kernel particle method(CVRKPM) correction function elasto-plasticity

A study of mechanical behavior of rock-fill materials with reference to particle crushing

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Science china(Technological Sciences) 2007年第z1期50卷 125-135页

作者： HUANG WenXiong1?, REN QingWen1 & SUN DeAn2.1 department of engineering {2., Hohai University, Nanjing 2.0098, china 2.department of Civil engineering, Shanghai University, Shanghai 2.0072. china department of engineering {2. Hohai University Nanjing 210098 China department of Civil engineering Shanghai University Shanghai 200072 China

In rock-fill dams of 2.0 to 300 m high, maximum compressive stress can exceed 6 MPa. At such a high stress level, rock-fill materials may experience particle crushing during shear. The material behavior is highly sophisticated exhibiting pressure and density dependency as well as particle crushing effects. Through scrutinizing the relevant experimental data on rock-fill materials and sands published in the literatures, this paper is focused on understanding basic mechanical characteristics of this sort of materials in the light of constitutive modelling.

关键词： rock-fill materials granular materials compressibility shear dilatancy particle crushing

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science china(Physics,mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3 1. mechanics department, Shandong University of Technology, Zibo 2.5049,{2. 2. Civil engineering department, Dalian University of Technology, Dalian 11602.,{2. 3. Mathematics department, Ocean University of{2., Qingdao 2.6071,{2. mechanics department Shandong University of Technology Zibo 255049 China Civil engineering department Dalian University of Technology Dalian 116024 China Mathematics department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

Modeling of multi-inclusion composites with interfacial imperfections:Micromechanical and numerical simulations

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Science china(Technological Sciences) 2010年第3期53卷 720-730页

作者： CHEN WeiQiu 1,ZHU XingYi 2.&HUANG ZhiYi 2.1 department of engineering {2.,Yuquan Campus,Zhejiang University,Hangzhou 31002.,china 2.Key Laboratory of Soft Soils and Geoenvironmental engineering,Ministry of Education department of Civil engineering,Zijingang Campus,Zhejiang University,Hangzhou 310058,china 1. department of engineering {2. Yuquan Campus Zhejiang University Hangzhou 310027 China2. Key Laboratory of Soft Soils and Geoenvironmental Engineering Ministry of Education Hangzhou 310058 China3. Department of Civil Engineering Zijingang Campus Zhejiang University Hangzhou 310058 China

A micromechanical approach based on a two-layer built-in model and a numerical simulation based on boundary element method are proposed to predict the effective properties of the multi-inclusion composite with imperfect *** spring model is introduced to simulate the interface *** two methods are compared with each other,and good agreement is *** effects of interface spring stiffness,volume ratio and stiffness of inclusions on the micro-and macro-mechanical behaviors of fiber-reinforced composites are *** is shown that the developed micromechanical method is very comprehensive and efficient for fast prediction of effective properties of composites,while the numerical method is very accurate in detailed modeling of the mechanical behavior of composites with multiple inclusions.

关键词： micromechanics boundary element method interface multi-inclusion composite effective elastic property

AFSTGCN:Prediction for multivariate time series using an adaptive fused spatial-temporal graph convolutional network

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Digital Communications and Networks 2024年第2期10卷 292-303页

作者： Yuteng Xiao Kaijian Xia Hongsheng Yin Yu-Dong Zhang zhenjiang Qian Zhaoyang Liu Yuehan Liang Xiaodan Li School of Information and Control engineering China University of Mining and TechnologyXuzhou221116China department of Informatics University of LeicesterLeicesterLE17RHUK The Affiliated Changshu Hospital of Soochow University Changshu215500China School of Computer Science and engineering Changshu Institute of TechnologySuzhou215500China

The prediction for Multivariate Time Series(MTS)explores the interrelationships among variables at historical moments,extracts their relevant characteristics,and is widely used in finance,weather,complex industries and other ***,it is important to construct a digital twin ***,existing methods do not take full advantage of the potential properties of variables,which results in poor predicted *** this paper,we propose the Adaptive Fused Spatial-Temporal Graph Convolutional Network(AFSTGCN).First,to address the problem of the unknown spatial-temporal structure,we construct the Adaptive Fused Spatial-Temporal Graph(AFSTG)***,we fuse the spatial-temporal graph based on the interrelationship of spatial ***,we construct the adaptive adjacency matrix of the spatial-temporal graph using node embedding ***,to overcome the insufficient extraction of disordered correlation features,we construct the Adaptive Fused Spatial-Temporal Graph Convolutional(AFSTGC)*** module forces the reordering of disordered temporal,spatial and spatial-temporal dependencies into rule-like *** dynamically and synchronously acquires potential temporal,spatial and spatial-temporal correlations,thereby fully extracting rich hierarchical feature information to enhance the predicted *** on different types of MTS datasets demonstrate that the model achieves state-of-the-art single-step and multi-step performance compared with eight other deep learning models.

关键词： Adaptive adjacency matrix Digital twin Graph convolutional network Multivariate time series prediction Spatial-temporal graph

Two-stop-two-slip motions of a dry friction oscillator

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Science china(Technological Sciences) 2010年第3期53卷 623-632页

作者： YANG ShaoPu1 & GUO ShuQi2.1 School of Mechanical engineering,Shijiazhuang Railway Institute,Shijiazhuang 050043,china {2.,Shijiazhuang Railway Institute,Shijiazhuang 050043,china 1. School of Mechanical engineering Shijiazhuang Railway Institute Shijiazhuang 050043 China2. Department of Engineering Mechanics Shijiazhuang Railway Institute Shijiazhuang 050043 China

This paper presents the investigation on the two-stop-two-slip (TSTS) motions in a dry friction *** is a kind of dissipated *** dry friction oscillator implies complicated stick-slip *** to its nonlinear non-smooth characters,it is difficult to analyze the stick-slip ***,TSTS motion is analyzed in this paper.A closed form solution of the TSTS motions is *** addition,parameter domain for the motion is *** general,there are no explicit solutions to transcendental equation in the closed form ***,explicit solutions are possible for special ***, Poincare map is structured to analyze the stability of the motions.

关键词： dry friction non-smooth dynamics stick-slip motion