检索结果-内蒙古大学图书馆

MULTICRITERIA OPTIMIZATION OF PIN-JOINTED STRUCTURES WITH OVERALL STABILITY CONSTRAINTS

INTERNATIONAL JOURNAL FOR numerical METHODS IN ENGINEERING 1992年第3期34卷 893-900页

作者： KACIANAUSKAS, R KUTAS, R MACIULEVICIUS, D Laboratory of Numerical Modelling and Research of Structures Vilnius Technical University Vilnius Lithuania

The optimization problem of elastic pin-jointed structures for overall stability conditions is presented in this paper. Two optimality criteria, the minimum of volume and the maximum of critical load, are taken into account. The optimization problem is presented as a non-linear multicriteria mathematical programming problem. Dimensional analysis enables natural division of the problem into two stages: optimization in space of non-dimensional variables with following specification of final dimensions. The sensitivity analysis and incremental solution scheme are used for the discription and solution of the optimization problem. Two sets of examples illustrate given models and a compromise solution. In the first sample of problems the optimization of the cross-sectional areas of the structure is considered while shape optimization is given in the second sample. Mathematical models of both examples are illustrated by numerical results. The shape optimization problem is characterized by a multiplicity of buckling modes and leads to complicated non-convex mathematical programming problems. Given examples are representative of complexities associated with practical problems.

关键词： Structural Design

来源：评论

学校读者我要写书评

暂无评论

numerical modelling methodology for design of miniaturised integrated products - An application to 3D CMM micro-probe development

Numerical modelling methodology for design of miniaturised i...

引用

2010 11th International Conference on Thermal, Mechanical and Multi-Physics Simulation, and Experiments in Microelectronics and Microsystems, EuroSimE 2010

作者： Rajaguru, Pushpa Stoyanov, Stoyan Tang, Ying Kit Bailey, Chris Claverley, James Leach, Richard Topham, David Centre for Numerical Modelling and Process Analysis University of Greenwich London United Kingdom Engineering Measurement Division National Physical Laboratory Teddington United Kingdom School of Engineering and Design Brunel University London United Kingdom

ISBN: (纸本)9781424470266

This paper presents an integrated numerically-driven modelling methodology for the design of miniaturised/integrated (Mintegrated) products and the selection/control of associated manufacturing processes. The focus is on the numerical techniques and methods that underpin several design procedures aiding the embodiment design stage of product development. A design assistant tool is developed as an end-user navigation interface that captures recommended design activities for the development of novel micro-integrated products and the supporting tools for their realisation. The main focus is placed on those design procedures comprising numerical methods for the simulation and modelling of the performance and behaviour of a product or process, and the analysis of their design in terms of risk of failure, capability of satisfying specification limits and optimality. The methodology enables an efficient and fast design process and can be applied to a wide range of microproduct developments. The applications range from the fabrication of micro- and nano-scale structures and components for heterogeneous systems, to micro-fluidics, metrology and embedded test devices. In this study, a number of design procedures and associated numerical techniques are demonstrated for the design of a new three-dimensional coordinate measuring machine (CMM) micro-probe developed at the National Physical laboratory (NPL, UK). ©2010 IEEE.

关键词： Probes

来源：评论

学校读者我要写书评

暂无评论

Microwave applications of TLM modeling techniques (Invited article)

引用

INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE COMPUTER-AIDED ENGINEERING 1996年第1期6卷 26-35页

作者： Christopoulos, C Smartt, CJ Numerical Modelling Laboratory Department of Electrical and Electronic Engineering University of Nottingham Nottingham NG7 2RD UK [*]Numerical Modelling Laboratory Department of Electrical and Electronic Engineering University of Nottingham Nottingham NG7 2RD UK

This article describes the essential features of the transmission-line modeling (TLM) technique and its application to the simulation of the behavior of microwave circuits. Emphasis is placed on presenting the general modeling approach and developments to the model to deal with practical microwave problems. Computational techniques and requirements are discussed with reference to dispersion, coarseness errors, and infinite boundaries. (C) 1996 John Wiley & Sons, Inc.

关键词： Microwave circuits

来源：评论

学校读者我要写书评

暂无评论

Compacting of particles for biaxial compression test by the discrete element method

引用

Journal of Civil Engineering and Management 2006年第2期12卷 153-161页

作者： Markauskas, Darius Kačianauskas, Rimantas Laboratory of Numerical Modelling Vilnius Gediminas Technical University Saulétekio al. 11 LT-10223 Vilnius Lithuania Dept. of Strength of Materials Laboratory of Numerical Modelling Vilnius Gediminas Technical University Lithuanian Academy of Sciences

numerical simulation of the compacting of particles for the biaxial compression test using the discrete element method is presented. Compacting is considered as the first independent step required for a proper simulation of the entire compression process. In terms of the continuum approach, compacting is regarded as generation of the initial conditions. Three different compacting scenarios with differently manipulated loading history on the boundaries, namely, compacting by using the moving rigid walls, by the static pressure using flexible membranes as well as combining the above two methods are considered. Discrete element methodology and basic relations, as well as formulation of the compacting problem and computational aspects of compacting are presented in detail. Each of the scenarios is illustrated by the numerical results. It has been found that the combined compacting scenario yields the required initial conditions exhibiting the best physically adjustable state of particles.

关键词： Compaction

来源：评论

学校读者我要写书评

暂无评论

Dominant Patterns of Summer Rainfall Anomalies in East China during 1951-2006

引用

Advances in Atmospheric Sciences 2012年第4期29卷 695-704页

作者：叶红陆日宇 State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

The dominant patterns of summer rainfall anomalies in East China were studied using Empirical Orthogonal Function （EOF） analysis. The results indicate that after the late 1970s, the first and second dominant patterns switched. During the period before the late 1970s, the spatial pattern of the first （second） dominant mode was the ＂Yangtze River pattern＂（the ＂South China pattern＂）, but this changed to the ＂South China pattern＂（the ＂Yangtze River pattern＂） after the late 1970s. This decadal change in the dominant patterns resulted from a significant decadal change in summer rainfall over South China after the late 1970s, i.e., a negative phase during 1978-1992 and a positive phase during 1993-2006. When the decadal variation of rainfall in East China is omitted from the analysis, the first and second dominant patterns represent the ＂Yangtze River pattern＂ and the ＂South China pattern＂, respectively. These results suggest that when decadal variation is included, the rainfall in China may be dominated by one mode during certain periods and by another in other periods. For the interannual variability when decadal variation is excluded, however, the first and second modes can be easily distinguished, and their order has been stable since at least 1951.

关键词： dominant patterns summer rainfall interannual variability South China decadal variation

来源：评论

学校读者我要写书评

暂无评论

Tibetan Plateau climate dynamics: recent research progress and outlook

引用

National Science Review 2015年第1期2卷 100-116页

作者： Guoxiong Wu Anmin Duan Yimin Liu Jiangyu Mao Rongcai Ren Qing Bao Bian He Boqi Liu Wenting Hu The State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

This paper reviews progress in the study of Tibetan Plateau(TP) climate dynamics over the past *** theoretical frameworks, including thermal adaptation and the TP sensible heat(SH) driving air-pump, have been developed to identify the mechanisms responsible for the circulation anomaly produced by thermal forcing of the TP. numerical simulations demonstrate that the thermal efects of large-scale orography, including the Tibetan and Iranian Plateaus(TIP), are crucial for the formation of the East Asian and South Asian summer monsoons(SASM) because the surface SH of the TIP is the major driver of the water vapor transport required for the genesis of the north branch of the SASM. he large-scale orography of the TP afects the Asian climate through thermal forcing in spring and summer, and mechanical forcing in winter. he TP forcing can also inluence the Asian summer monsoon(ASM) onset over the Bay of Bengal(BOB) by enhancing the BOB warm pool at the surface and by modulating the South Asian High(SAH) in the upper troposphere. On intra-seasonal timescales, the TP thermal forcing signiicantly modulates spring rainfall in southern China and generates the biweekly oscillation of the SAH in summer. Despite climate warming, the atmospheric heat source over the TP, particularly the spring SH,exhibits a clear weakening trend from the 1980 s to 2000 s. his weakening of the spring SH contributed to the anomalous ‘dry in the north' and ‘wet in the south' rainfall patern observed over East China. Also discussed are challenges to further understanding the mechanism of TP forcing on the multi-scale variability of the ASM.

关键词： Tibetan Plateau climate dynamics Asian monsoon land–air–sea interaction numerical simulation

来源：评论

学校读者我要写书评

暂无评论

Oceanic Climatology in the Coupled Model FGOALS-g2: Improvements and Biases

引用

Advances in Atmospheric Sciences 2013年第3期30卷 819-840页

作者：林鹏飞俞永强刘海龙 State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences

The present study examines simulated oceanic climatology in the Flexible Global Ocean-Atmosphere- Land System model, Grid-point Version 2 （FGOALS-g2） forced by historical external forcing data. The oceanic temperatures and circulations in FGOALS-g2 were found to be comparable to those observed, and substantially improved compared to those simulated by the previous version, FGOALS-gl.0. Compared with simulations by FGOALS-gl.0, the shallow mixed layer depths were better captured in the eastern Atlantic and Pacific Ocean in FGOALS-g2. In the high latitudes of the Northern Hemisphere, the cold biases of SST were about 1℃-5℃ smaller in FGOALS-g2. The associated sea ice distributions and their seasonal cycles were more realistic in FGOALS-g2. The pattern of Atlantic Meridional Overturning Circulation （AMOC） was better simulated in FGOALS-g2, although its magnitude was larger than that found in observed data. The simulated Antarctic Circumpolar Current （ACC） transport was about 140 Sv through the Drake Passage, which is close to that observed. Moreover, Antarctic Intermediate Water （AAIW） was better captured in FGOALS-g2. However, large SST cold biases （〉3℃） were still found to exist around major western boundary currents and in the Barents Sea, which can be explained by excessively strong oceanic cold advection and unresolved processes owing to the coarse resolution. In the Indo-Pacific warm pool, the cold biases were partly related to the excessive loss of heat from the ocean. Along the eastern coast in the Atlantic and Pacific Oceans, the warm biases were due to overestimation of shortwave radiation. In the Indian Ocean and Southern Ocean, the surface fresh biases were mainly due to the biases of precipitation. In the tropical Pacific Ocean, the surface fresh biases （〉2 psu） were mainly caused by excessive precipitation and oceanic advection. In the Indo-Pacific Ocean, fresh biases were also found to dominate in the upper 1000 m, except in the northeastern Indian Ocea

关键词： FGOALS-g2 oceanic climatology temperature salinity ocean circulation

来源：评论

学校读者我要写书评

暂无评论

Symplectic operator method and its test

引用

PROGRESS IN NATURAL SCIENCE 1997年第3期7卷 345-353页

作者： Wang, B Ji, ZZ Zeng, QC Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100080 China

The symplectic operator method is developed based on the square conservation scheme and the algorithm of symplectic geometry. In the method, the generalized symplectic definitions and the construction of the infinitesimally symplectic difference operator are included. It provides a new effective way to generalize and apply the algorithm of symplectic geometry to numerical simulations of partial differential equations.

关键词： symplectic operator Hamilton difference scheme infinite dimension

来源：评论

学校读者我要写书评

暂无评论

Study on Atmospheric Travelling Wave Solutions and Review of Its Present Developments

引用

Advances in Atmospheric Sciences 1993年第4期10卷 435-446页

作者：黄思训张铭 Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Chinese Academy of Sciences Beijing 100080

The scientific achievements of travelling waves in a barotropic atmosphere are introduced, including i) the existence conditions of periodic solutions (wavetrain solutions) and solitary wave solutions (pulse solutions), together with the solution finding methods and a series of related problems, ii) seeking solutions of monotonous wave (wave front) and of nonmonotonous travelling wave (oscillatory wave) by using phase plane shooting technique and hi) progress in the study of travelling wave solution at home and abroad. The investigation of travelling wave solutions in recent years has been found in mathematics, physics, chemistry, biology and other sciences. Over the past decade the problem has been the subject of much interest and become an important area of research. So it is no doubt of great significance to investigate the travelling wave solutions and thereby explain phenomena of weather.

关键词： Barotropic atmosphere Wavetrain Wave front Travelling wave solution (TWS) Pulse solution Nonmonotonous travelling wave solution

来源：评论

学校读者我要写书评

暂无评论

Development of a continuum-consistent discrete element model for solids using the triangle finite element

Development of a continuum-consistent discrete element model...

引用

6th International Conference on Engineering Computational Technology, ECT 2008

作者： Vadluga, V. Kačianauskas, R. Laboratory of Numerical Modelling Vilnius Gediminas Technical University Lithuania

ISBN: (纸本)9781905088249

This paper addresses the development of the lattice-type discrete element (DE) model for planar classical continuum by combining it with the finite element technique. The proposed continuum-consistent approach assumes that deformation behaviour of solid can be described by translational degrees of freedom and may be characterised as an alternative lattice model with central and angular interaction. The developed DE model can represent arbitrary geometry of the triangle lattice and is independent of the values of Poison's ratio. It was implemented into the original DEM code DEMMAT and validated by simulating the dynamic behaviour of the plane stress problem against the 'exact' FE results. Brittle cracking with randomly distributed tensile strength properties of the material is considered as an application case. © 2008 Civil-Comp Press.

关键词： Degrees of freedom (mechanics)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：