期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
Total loads modeling and geological adaptability analysis for mixed soil-rock tunnel boring machines
1
作者 Wencong Qi Lihui Wang +2 位作者 Siyang Zhou Yilan Kang Qian Zhang 《Underground Space》 SCIE EI 2022年第3期337-351,共15页
Rock-soil interface mixed ground(RSI)is often encountered in tunnel construction.The excavation loads of tunnel boring machines(TBMs)are controlled by the interaction characteristics between TBM and rock/soil layers.T... Rock-soil interface mixed ground(RSI)is often encountered in tunnel construction.The excavation loads of tunnel boring machines(TBMs)are controlled by the interaction characteristics between TBM and rock/soil layers.The different properties of rock and soil cause the varying interaction range and stress distribution.Currently,there have been several studies available to estimate excavation loads under RSI,and the conclusion is that the total loads increase with increasing the rock layer proportion in the excavation face.However,the previous studies cannot take the difference of rock/soil properties into account,except for the calculation of cutters loads.Therefore,the interaction characteristics between RSI and TBM is unclear.This paper analyzes the interaction characteristics between TBM’s main components and complex geological conditions(e.g.,layered soil,layered rock,and RSI condition).A model is proposed to calculate the total thrust and total torque assuming quasi-static equilibrium of the tunneling equipment.The rationality and applicability of the model are discussed and verified by two typical projects.Furthermore,the geological adaptability is discussed in terms of the excavation difficulty and the matching relationship between total torque and total thrust.The results indicate that when the rock layer proportion in the excavation face increases,the reduction of overall extrusion and friction loads is 1.5 times higher than the increase of disc cutters breaking load.The total loads and the ratio of the total torque to total thrust decrease approximately linearly.There is a power function relationship between the excavation difficulty index and the penetration depth.The results of this study provide an important reference for the total loads design of equipment propulsion systems and the parameter adjustment during tunnel construction. 展开更多
关键词 Rock-soil interface mixed ground Tunnel boring machine Total loads prediction Thrust and torque Geological adaptability analysis
原文传递
Regularized least-squares migration of simultaneous-source seismic data with adaptive singular spectrum analysis 被引量:12
2
作者 Chuang Li Jian-Ping Huang +1 位作者 Zhen-Chun Li Rong-Rong Wang 《Petroleum Science》 SCIE CAS CSCD 2017年第1期61-74,共14页
Simultaneous-source acquisition has been recog- nized as an economic and efficient acquisition method, but the direct imaging of the simultaneous-source data produces migration artifacts because of the interference of... Simultaneous-source acquisition has been recog- nized as an economic and efficient acquisition method, but the direct imaging of the simultaneous-source data produces migration artifacts because of the interference of adjacent sources. To overcome this problem, we propose the regularized least-squares reverse time migration method (RLSRTM) using the singular spectrum analysis technique that imposes sparseness constraints on the inverted model. Additionally, the difference spectrum theory of singular values is presented so that RLSRTM can be implemented adaptively to eliminate the migration artifacts. With numerical tests on a fiat layer model and a Marmousi model, we validate the superior imaging quality, efficiency and convergence of RLSRTM compared with LSRTM when dealing with simultaneoussource data, incomplete data and noisy data. 展开更多
关键词 Least-squares migration Adaptive singularspectrum analysis Regularization Blended data
下载PDF
h-ADAPTIVITY ANALYSIS BASED ON MULTIPLE SCALE REPRODUCING KERNEL PARTICLE METHOD 被引量:4
3
作者 ZHANG Zhi-qian(张智谦) ZHOU Jin-xiong(周进雄) +2 位作者 WANG Xue-ming(王学明) ZHANG Yan-fen(张艳芬) ZHANG Ling(张陵) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第8期1064-1071,共8页
An h-adaptivity analysis scheme based on multiple scale reproducing kernel particle method was proposed, and two node refinement strategies were constructed using searching-neighbor-nodes(SNN) and local-Delaunay-tri... An h-adaptivity analysis scheme based on multiple scale reproducing kernel particle method was proposed, and two node refinement strategies were constructed using searching-neighbor-nodes(SNN) and local-Delaunay-triangulation(LDT) techniques, which were suitable and effective for h-adaptivity analysis on 2-D problems with the regular or irregular distribution of the nodes. The results of multiresolution and h- adaptivity analyses on 2-D linear elastostatics and bending plate problems demonstrate that the improper high-gradient indicator will reduce the convergence property of the h- adaptivity analysis, and that the efficiency of the LDT node refinement strategy is better than SNN, and that the presented h-adaptivity analysis scheme is provided with the validity, stability and good convergence property. 展开更多
关键词 meshfree method reproducing kernel particle method multiresolution analysis adaptive analysis
下载PDF
An Improved Adaptive Multi-way Principal Component Analysis for Monitoring Streptomycin Fermentation Process 被引量:8
4
作者 何宁 王树青 谢磊 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第1期96-101,共6页
Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), usi... Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), using the process variable trajectories to monitoring the batch process is presented in this paper. It does not need to estimate or fill in the unknown part of the process variable trajectory deviation from the current time until the end. The approach is based on a MPCA method that processes the data in a sequential and adaptive manner. The adaptive rate is easily controlled through a forgetting factor that controls the weight of past data in a summation. This algorithm is used to evaluate the industrial streptomycin fermentation process data and is compared with the traditional MPCA. The results show that the method is more advantageous than MPCA, especially when monitoring multi-stage batch process where the latent vector structure can change at several points during the batch. 展开更多
关键词 step-by-step adaptive multi-way principal component analysis batch monitoring streptomycin fermentation static process monitoring
下载PDF
h-ADAPTIVE ANALYSIS BASED ON MESHLESS LOCAL PETROV-G ALERKIN METHOD WITH B SPLINE WAVELET FOR PLATES AND SHELLS 被引量:1
5
作者 Di Li Zhongqin Lin 《Acta Mechanica Solida Sinica》 SCIE EI 2009年第4期337-346,共10页
Using the two-scale decomposition technique, the h-adaptive meshless local Petrov- Galerkin method for solving Mindlin plate and shell problems is presented. The scaling functions of B spline wavelet are employed as t... Using the two-scale decomposition technique, the h-adaptive meshless local Petrov- Galerkin method for solving Mindlin plate and shell problems is presented. The scaling functions of B spline wavelet are employed as the basis of the moving least square method to construct the meshless interpolation function. Multi-resolution analysis is used to decompose the field variables into high and low scales and the high scale component can commonly represent the gradient of the solution according to inherent characteristics of wavelets. The high scale component in the present method can directly detect high gradient regions of the field variables. The developed adaptive refinement scheme has been applied to simulate actual examples, and the effectiveness of the present adaptive refinement scheme has been verified. 展开更多
关键词 meshless methods meshless local Petrov-Galerkin method multi-resolution analysis adaptive analysis plate and shell
下载PDF
Adaptive FEM Analysis of the Temperature Field of Pistons in Diesel Engines and Their Thermal Stress and Deformation Calculation 被引量:1
6
作者 覃文洁 张儒华 左正兴 《Journal of Beijing Institute of Technology》 EI CAS 2004年第4期418-421,共4页
The adaptive FEM analysis of the temperature field of the piston in one diesel engine is given by using the ANSYS software. By making full use of the post results provided by the software, the posteriori error estimat... The adaptive FEM analysis of the temperature field of the piston in one diesel engine is given by using the ANSYS software. By making full use of the post results provided by the software, the posteriori error estimation and adaptive accuracy meshing algorithm is developed. So the blindness of the mesh design through experiences can be avoided, and the accuracy requirement is adapted to the relative temperature gradient distribution across the entire domain. Therefore the meshes and solutions can be obtained at the same time. Based on the temperature field analysis, the thermal stress and deformation fields are calculated as well. The results show that the stress concentrates on the edge of the piston pin boss and the inside surface of the first ring groove, and the deformation of the head of the piston is greatest. But the difference between the long and short axes of the bottom cross section is greatest. 展开更多
关键词 adaptive analysis temperature field thermal structural analysis PISTON
下载PDF
Adaptive and local analysis of climate data
7
作者 Wu Zhaohua Huang Norden E Wallace John M 《Engineering Sciences》 EI 2014年第2期36-40,共5页
This paper focuses on how to extract physically meaningful information from climate data,with emphases placed on adaptive and local analysis. It is argued that many traditional statistical analysis methods with rigoro... This paper focuses on how to extract physically meaningful information from climate data,with emphases placed on adaptive and local analysis. It is argued that many traditional statistical analysis methods with rigorous mathematical footing may not be efficient in extracting essential physical information from climate data;rather,adaptive and local analysis methods that agree well with fundamental physical principles are more capable of capturing key information of climate data. To illustrate the improved power of adaptive and local analysis of climate data,we also introduce briefly the empirical mode decomposition and its later developments. 展开更多
关键词 statistical analysis of data adaptive analysis of data locality of analysis empirical mode decom- position ensemble empirical mode decomposition global warming trend multidecadal climate variability
下载PDF
Preliminary Discussion on the Refinement Mesh Generation for Adaptive Analysis
8
作者 Qian Tang Yu Ren 《Journal of Applied Mathematics and Physics》 2020年第8期1560-1567,共8页
In recent years, due to the rapid development of computer hardware and the urgent need of complex engineering problems, great support has been provided in the related fields of unstructured mesh generation. A large nu... In recent years, due to the rapid development of computer hardware and the urgent need of complex engineering problems, great support has been provided in the related fields of unstructured mesh generation. A large number of research results show that the adaptive analysis is an effective way to improve the efficiency and precision of the numerical calculation. The reliable error estimation and the powerful mesh generation are two key problems in the process of adaptive numerical analysis. H-type refinement strategy adding the new nodes in the high error area, gradually refines the mesh to reduce the size of the element to achieve the purpose of mesh adaptation;this strategy is simple, intuitive and easy to program. Although the calculation accuracy of unstructured triangle and tetrahedron elements is not high, these elements are suitable for discretization of any complex problem domain, and have a wider range of application in academic and engineering fields. 展开更多
关键词 Adaptive analysis DELAUNAY REFINEMENT TRIANGLE TETRAHEDRON
下载PDF
Introducing Adaptive Analysis Methods: The Present Analysis &Future Analysis
9
作者 Kunto Wibowo Agung Prodjonoto 《Journal of Analytical Sciences, Methods and Instrumentation》 2020年第2期43-57,共15页
Mastery of theory, analysis, approach models and decision making, is increasingly important, so finding analytical methods to achieve something better is a logical consequence. For this reason, adaptive analysis metho... Mastery of theory, analysis, approach models and decision making, is increasingly important, so finding analytical methods to achieve something better is a logical consequence. For this reason, adaptive analysis method is introduced, which is a method of dynamizing SWOT analysis using commutative properties with the operation of the cross-axis coordinate (X;Y), based on the theory of lines and rules of a sword, phenomenal, natural and relevant, to obtain a grand strategy chosen as a unified strategy like two sides of a coin. The method used is the theoretical and empirical study of adaptive analysis on one of the global issues, namely phenomenal terrorism until now. It is hoped that this method can be used in a variety of problems and is highly determined how a talent plays a role and is not intended to criticize existing analytical methods that have been used. 展开更多
关键词 Decision Making Adaptive analysis Method
下载PDF
Theoretical convergence analysis of complex Gaussian kernel LMS algorithm
10
作者 Wei Gao Jianguo Huang +1 位作者 Jing Han Qunfei Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期39-50,共12页
With the vigorous expansion of nonlinear adaptive filtering with real-valued kernel functions,its counterpart complex kernel adaptive filtering algorithms were also sequentially proposed to solve the complex-valued no... With the vigorous expansion of nonlinear adaptive filtering with real-valued kernel functions,its counterpart complex kernel adaptive filtering algorithms were also sequentially proposed to solve the complex-valued nonlinear problems arising in almost all real-world applications.This paper firstly presents two schemes of the complex Gaussian kernel-based adaptive filtering algorithms to illustrate their respective characteristics.Then the theoretical convergence behavior of the complex Gaussian kernel least mean square(LMS) algorithm is studied by using the fixed dictionary strategy.The simulation results demonstrate that the theoretical curves predicted by the derived analytical models consistently coincide with the Monte Carlo simulation results in both transient and steady-state stages for two introduced complex Gaussian kernel LMS algonthms using non-circular complex data.The analytical models are able to be regard as a theoretical tool evaluating ability and allow to compare with mean square error(MSE) performance among of complex kernel LMS(KLMS) methods according to the specified kernel bandwidth and the length of dictionary. 展开更多
关键词 nonlinear adaptive filtering complex Gaussian kernel convergence analysis non-circular data kernel least mean square(KLMS).
下载PDF
The development and application of ultra fast cooling in hot-rolled
11
作者 YE Xiaoyu,ZUO Jun and ZHANG Kaihua PanGang Group Research Institute Co.,Ltd.,Panzhihua,Chengdu 611731,Sichuan,China 《Baosteel Technical Research》 CAS 2010年第S1期36-,共1页
Ultra fast cooling is a new technology which used to control the hot-rolling strip cooling in recent years on the international developed.If suitably cooperated with a number of other new controlled rolling technologi... Ultra fast cooling is a new technology which used to control the hot-rolling strip cooling in recent years on the international developed.If suitably cooperated with a number of other new controlled rolling technologies,can achieve fast and accurate temperature control in the hot-rolled strip production process to obtain corresponding transformation microstructure and ideal mechanical properties.This article describes the technical principle and layout of ultra fast cooling in hot-rolled as well as application profiles in the major iron and steel enterprise in China and abroad.Carried out the layout of ultra fast cooling analysis on the adaptability of steel that install between the finishing mill and laminar cooling,on this basis,proposed the use of ultra fast cooling technology proposals. 展开更多
关键词 ultra fast cooling controlled rolling and controlled cooling adaptability analysis
下载PDF
ADAPTIVE MESHLESS METHOD BASED ON LOCAL FIT TECHNOLOGY 被引量:1
12
作者 LouLuliang ZengPan 《Acta Mechanica Solida Sinica》 SCIE EI 2005年第2期164-172,共9页
An h-adaptive meshless method is proposed in this paper. The error estimation is based on local fit technology, usually confined to Voronoi Cells. The error is achieved by comparison of the computational results with ... An h-adaptive meshless method is proposed in this paper. The error estimation is based on local fit technology, usually confined to Voronoi Cells. The error is achieved by comparison of the computational results with smoothed ones, which are projected with Taylor series. Voronoi Cells are introduced not only for integration of potential energy but also for guidance of refinement. New nodes are placed within those cells with high estimated error. At the end of the paper, two numerical examples with severe stress gradient are analyzed. Through adaptive analysis accurate results are obtained at critical subdomains, which validates the efficiency of the method. 展开更多
关键词 adaptive analysis error estimation meshless method local fit
下载PDF
DESIGN OF RECONFIGURABLE MANUFACTURING SYSTEMS WITH STRONGLY COUPLED NATURE 被引量:1
13
作者 LANG Sherman Y T 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第1期91-95,共5页
Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for com... Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects: (1) To modularize products and make them as less differences as possible; (2) To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect (2), i.e. how to design a reconfignrable manufacturing system (RMS) so that it can be competent to accomplish various processes optimally; Reconfignrable robot system (RRS) is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory (ADT) is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis. 展开更多
关键词 Mass customisation Reconfignrable manufacturing systems Reconfignrable robotic system analysis Synthesis Architecture adaptability Reconfignrability Configuration design
下载PDF
Strategies for h-Adaptive Refinement for a Finite Element Treatment of Harmonic Oscillator Schrodinger Eigenproblem
14
作者 T.D.Young R.Armiento 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1017-1023,共7页
A Schrodinger eigenvalue problem is solved for the 219 quantum simple harmonic oscillator using a finite element discretization of real space within which elements are adaptively spatially refined. We compare two comp... A Schrodinger eigenvalue problem is solved for the 219 quantum simple harmonic oscillator using a finite element discretization of real space within which elements are adaptively spatially refined. We compare two competing methods of adaptively discretizing the real-space grid on which computations are performed without modifying the standard polynomial basis-set traditionally used in finite element interpolations; namely, (i) an application of the Kelly error estimator, and (ii) a refinement based on the local potential level. When the performance of these methods are compared to standard uniform global refinement, we find that they significantly improve the total time spent in the eigensolver. 展开更多
关键词 adaptive finite element analysis Harmonic oscillator problems Schrodinger equation
下载PDF
Transparency in Meat Production: Consumer Perceptions at the Point of Sale
15
作者 L. Arens M. Deimel L. Theuvsen 《Journal of Agricultural Science and Technology(B)》 2011年第8期1134-1145,共12页
As a result of a large number of food scandals, societal interest in transparency in the food sector has grown considerably. Hence, the creation of transparency in the production process has been the focus of recent l... As a result of a large number of food scandals, societal interest in transparency in the food sector has grown considerably. Hence, the creation of transparency in the production process has been the focus of recent legislation. In addition to tracking and tracing, one finds in the public discussion an increasing number of demands for further information on such issues as food safety, animal and environmental protection and the sustainability of food production processes. However, it has not yet been sufficiently clarified which information about the production process--and thus which level of transparency--is actually desired or can actually be processed by consumers at the point of sale. In order to analyze this topic from the viewpoint of consumers, a large-scale empirical study has been conducted. This research uses an adaptive conjoint analysis to determine what transparency expectations consumers have with regards to information on packaged pork. Initial results show a very heterogeneous demand for information. Furthermore, consumers' demand for more information sometimes does not match their actual benefit profiles. The results provide insight into consumers' information needs and their willingness to pay for greater transparency; they also have interesting implications for meat processors' product development strategies. 展开更多
关键词 TRANSPARENCY pork production adaptive conjoint analysis packaged pork consumer perception.
下载PDF
Study of Signal Processing Algorithm in the Receiving End of Through-the-Earth Communications of Elastic Wave
16
作者 郭银景 杨军 +1 位作者 穆卫涛 陈赓 《Journal of Measurement Science and Instrumentation》 CAS 2010年第2期166-169,共4页
In the research of elastic wave signal detection algorithm, a method based on adaptive wavelet analysis and segmentation threshold processing of the channel noise removal methods is suggested to overcome the effect of... In the research of elastic wave signal detection algorithm, a method based on adaptive wavelet analysis and segmentation threshold processing of the channel noise removal methods is suggested to overcome the effect of noise, which is prcduced by absorption loss, scattering loss, reflection loss and multi-path effect during the elastic wave in the transmission undelgroound. The method helps to realize extraction and recovery of weak signal of elastic wave from the multi-path channel, and simulation study is carded out about wavelet de-noising effects of the elastic wave and obtained satisfactory results. 展开更多
关键词 through-tbe-earth oommunications of elastic wave weak signal detection adaptive wavelet analysis
下载PDF
Fundamentals and progress of the manifold method based on independent covers
17
作者 SU HaiDong LIN ShaoZhong +2 位作者 XIE ZhiQiang GONG YaQi QI YongFeng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2024年第4期966-991,共26页
Aiming to solve mesh generation,computational stability,accuracy control,and other problems encountered with existing numerical methods,such as the finite element method and the finite volume method,a new numerical co... Aiming to solve mesh generation,computational stability,accuracy control,and other problems encountered with existing numerical methods,such as the finite element method and the finite volume method,a new numerical computational method for continuum mechanics,namely the manifold method based on independent covers(MMIC),is proposed based on the concept of mathematical manifolds,to form partitioned series solutions of partial differential equations.As partitions,the cover meshes have the characteristics of arbitrary shape,arbitrary connection,and arbitrary refinement.They are expected to fundamentally solve the mesh generation problem and can also simulate the precise geometric boundaries of the CAD model and strictly impose boundary conditions.In the selection of series solutions,local analytical solutions(such as series solutions at crack tips and series solutions in infinite domains)or proper forms of complete series can be used to reflect the local or global characteristics of the physical field to accelerate convergence.Various applications are presented.A new method of beam,plate,and shell analysis is proposed.The deformation characteristics of beams,plates,and shells are simulated with polynomial series of suitable forms,and the analysis of curved beams and shells with accurate geometric representation is realized.For the static elastic analysis of two-dimensional structures,a mesh splitting algorithm is proposed,and h-p version adaptive analysis is carried out with error estimation.Thus,automatic computation integrated with CAD is attempted.Adaptive analysis is also attempted for the solution of differential equations of fluids.For the one-dimensional convection-diffusion equation and Burgers equation,calculation results with high precision are obtained in strong convection and shock wave simulations,avoiding nonphysical oscillations.And solving the two-dimensional incompressible Navier-Stokes equation is also attempted.The series solution formula is used to obtain the physical quantity of interest of the material at a space point to eliminate the convection terms.Thus,geometrically nonlinear problems can be analyzed in fixed meshes,and a new method of free surface tracking is proposed. 展开更多
关键词 series solutions mesh generation adaptive analysis fixed meshes numerical manifold method
原文传递
AN APPARENT TEMPERATURE MODEL BASED ON THERMAL EQUILIBRIUM
18
作者 于波 刘梅 姚克敏 《Acta meteorologica Sinica》 SCIE 2004年第1期117-128,共12页
In this paper,a comprehensive analysis and review of the advances in the research of human body comfort degree is made.Based on the studies of human thermal equilibrium theories contributed by previous researchers,dif... In this paper,a comprehensive analysis and review of the advances in the research of human body comfort degree is made.Based on the studies of human thermal equilibrium theories contributed by previous researchers,different apparent temperature models corresponding to different environments are set up in accordance with the current situation and the characteristics of metabolism in different groups of people in China.After case studies and comparison with present dominant human body comfort degree statistical models,it is proved that the apparent temperature models have high rationality and wide adaptability.Furthermore,the comfort scaling standard according to apparent temperature is suggested,which is suitable for the middle latitude regions in China. 展开更多
关键词 thermal equilibrium equation apparent temperature model adaptability analysis comfort index
原文传递
OPTIMALITY OF LOCAL MULTILEVEL METHODS FOR ADAPTIVE NONCONFORMING P1 FINITE ELEMENT METHODS 被引量:1
19
作者 Xuejun Xu Huangxin Chen R.H.W. Hoppe 《Journal of Computational Mathematics》 SCIE CSCD 2013年第1期22-46,共25页
In this paper, a local multilevel product algorithm and its additive version are con- sidered for linear systems arising from adaptive nonconforming P1 finite element approx- imations of second order elliptic boundary... In this paper, a local multilevel product algorithm and its additive version are con- sidered for linear systems arising from adaptive nonconforming P1 finite element approx- imations of second order elliptic boundary value problems. The abstract Schwarz theory is applied to analyze the multilevel methods with Jaeobi or Gauss-Seidel smoothers per- formed on local nodes on coarse meshes and global nodes on the finest mesh. It is shown that the local multilevel methods are optimal, i.e., the convergence rate of the multilevel methods is independent of the mesh sizes and mesh levels. Numerical experiments are given to confirm the theoretical results. 展开更多
关键词 Local multilevel methods Adaptive nonconforming P1 finite element methods Convergence analysis Optimality.
原文传递
An h-adaptive numerical manifold method for solid mechanics problems
20
作者 YU ChangYi LIU Feng XU Ying 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第6期923-933,共11页
The numerical manifold method(NMM) features its dual cover systems, namely the mathematical cover and physical cover,which provide a unified framework for mechanics problems involving continuum and discontinuum deform... The numerical manifold method(NMM) features its dual cover systems, namely the mathematical cover and physical cover,which provide a unified framework for mechanics problems involving continuum and discontinuum deformation. Uniform finite element meshes can be and are usually used to construct the mathematical cover. Though this strategy can handle different kinds of problems in a unified way, it is not economical for cases with steep deformation gradients or singularities. In this paper, using the recovery-based error estimator, an h-adaptive NMM on quadtree meshes is proposed to deal with such cases. The quadtree meshes serve as the mathematical meshes, on which the local refinement is carried out. When the quadtree meshes are refined,the corresponding mathematical cover, physical cover and manifold elements are updated accordingly. To handle the hanging nodes in the quadtree meshes, we resort to mean value coordinates. Comparing to the refinement based on manifold elements,the proposed strategy guarantees consistent structured meshes throughout the adaptive process, thus retaining the unique feature of original NMM. In contrast with polygonal finite element method, an advantage of the proposed method is that the meshes do not need to conform to the crack face and material boundary, which means the adaptive NMM is very suitable for problems with complex geometric boundary. Several representative mechanics problems, including crack problems, are analyzed to investigate the effectiveness of the proposed method. It is demonstrated that the proposed adaptive NMM has higher accuracy and better performance comparing to uniform refinement strategy. 展开更多
关键词 numerical manifold method (NMM) adaptive analysis quadtree meshes mean value coordinates cover refinement
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部