检索结果-内蒙古大学图书馆

Intelligent simulation of multibody dynamics: Space-state and descriptor methods in sequential and parallel computing environments

引用

MULTIBODY SYSTEM DYNAMICS 2000年第1期4卷 55-73页

作者： Cuadrado, J Cardenal, J Morer, P Bayo, E Univ A Coruna Escuela Politecn Super Ferrol 15403 Spain Univ Navarra Sch Engn & Architecture E-31080 Pamplona Spain

Real-time dynamic simulation of large, realistic and complex multibody systems is essential in developing modern technologies such as virtual prototyping, man-in-the-loop simulators and intelligent vehicle control systems. In order to achieve real-time performance, current commercial codes require the use of large costly computers, thus limiting the number of potential users. This paper shows that real-time can be achieved on medium-size workstations if, on the one hand, an adequate combination of modeling, dynamic formulation, and numerical integration scheme is selected and, on the other hand, advantage is taken of sparse matrix technology and parallel computing. A study of space-state and descriptor methods involving the dynamics of a whole vehicle model is carried out and in conclusion, two methods are proposed as the best candidates for real-time simulation.

关键词： real-time-simulation multibody dynamics solution algorithms parallel computing sparse matrix technologies

来源：评论

学校读者我要写书评

暂无评论

Bibliometric analysis and system review of vehicle routing optimization for emergency material distribution

引用

Journal of Traffic and Transportation Engineering(English Edition) 2022年第6期9卷 893-911页

作者： Jinxing Shen Kun Liu Changxi Ma Yongpeng Zhao Chuwei Shi College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China School of Traffc and Transportation Lanzhou Jiaotong UniversityLanzhou 730070China

Determining the optimal vehicle routing of emergency material distribution(VREMD)is one of the core issues of emergency management,which is strategically important to improve the effectiveness of emergency response and thus reduce the negative impact of large-scale emergency *** summarize the latest research progress,we collected 511VREMD-related articles published from 2010 to the present from the Scopus database and conducted a bibliometric analysis using VOSviewer ***,we cautiously selected 49 articles from these publications for system review;sorted out the latest research progress in model construction and solution algorithms;and summarized the evolution trend of keywords,research gaps,and future *** results show that domestic scholars and research organizations held an unqualified advantage regarding the number of published ***,these organizations with the most publications performed poorly regarding the number of literature *** and the US have contributed the vast majority of the literature,and there are close collaborations between researchers from both *** optimization model of VREMD can be divided into single-,multi-,and joint-objective *** shortest travel time is the most common optimization objective in the single-objective optimization *** scholars focus on multiobjective optimization models to consider conflicting objectives *** recent literature,scholars have focused on the impact of uncertainty and special events(e.g.,COVID-19)on ***,some scholars focus on joint optimization models to optimize vehicle routes and central locations(or material allocation)*** algorithms can be divided into two primary categories,i.e.,mathematical planning methods and intelligent evolutionary *** branch and bound algorithm is the most dominant mathematical planning algorithm,while genetic algorithms and their enhancements are the most co

关键词： Transportation engineering Vehicle routing of emergency materials distribution Bibliometric analysis Optimization model solution algorithms

来源：评论

学校读者我要写书评

暂无评论

The ortho-semi-torsional (OST) spring analogy method for 3D mesh moving boundary problems

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2007年第4-6期196卷 747-765页

作者： Markou, George A. Mouroutis, Zacharias S. Charmpis, Dimos C. Papadrakakis, Manolis Natl Tech Univ Athens Inst Struct Anal & Seism Res GR-15780 Athens Greece Univ Cyprus Dept Civil & Environm Engn CY-1678 Nicosia Cyprus

In this paper a new mesh update technique is presented for the effective treatment of 3D mesh moving boundary problems. The proposed mesh update scheme utilizes an ortho-semi-torsional (OST) spring analogy concept to construct a fictitious elasticity problem with imposed boundary displacements, which is efficiently solved with an algorithm based on the preconditioned conjugate gradient (PCG) method. The PCG-based solution algorithm is also applied to three other mesh update techniques available in the literature, namely the torsional, the semi-torsional and the ball-vertex spring analogy schemes. The four spring analogy methods are comparatively assessed with respect to their robustness and computational efficiency in handling 3D benchmark problems, as well as more involved test cases such as the AGARD wing 445.6 and a 3D three-element airfoil. It is demonstrated that the OST spring analogy concept combined with a PCG-type algorithm for the solution of fictitious elasticity problems provides robustness for substantially distorted meshes and computational efficiency for large-scale problems. (c) 2006 Elsevier B.V. All rights reserved.

关键词： coupled problems mesh update solution algorithms preconditioned conjugate gradient

来源：评论

学校读者我要写书评

暂无评论

Simulation of special loading conditions by means of non-linear constraints imposed through Lagrange multipliers

引用

COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING 2002年第10期18卷 699-709页

作者： Gutiérrez, MA Askes, H Tech Univ Delft Fac Aerosp Engn Koiter Inst NL-2600 GB Delft Netherlands Delft Univ Technol Fac Civil Engn & Geosci Koiter Inst NL-2600 GA Delft Netherlands

This paper discusses the necessity and handling of non-linear constraint equations to describe the behaviour of properties of the loading system such as, e.g. smooth free-rotating loading platens. An exact, non-linear formulation for a smooth loading platen is derived and its incorporation into the equilibrium equations is presented. For this purpose, the Lagrange multiplier method is used. The solution of the equilibrium equations by means of a Newton-Raphson algorithm is also outlined. The proposed approach is validated on a patch of two finite elements and applied to a compression-bending test on a pre-notched specimen. It is observed that use of a linearized approximation of the boundary constraint can lead to errors in the description of the motion of the constrained nodes. Thus, the non-linear formulation is preferable. Copyright (C) 2002 John Wiley Sons, Ltd.

关键词： solution algorithms boundary conditions non-linear constraints Lagrange multipliers finite element method

来源：评论

学校读者我要写书评

暂无评论

Overlapping and non-overlapping domain decomposition methods for large-scale meshless EFG simulations

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2012年 229卷 128-141页

作者： Metsis, P. Papadrakakis, M. Natl Tech Univ Athens Inst Struct Anal & Antiseism Res GR-15780 Athens Greece

Meshless methods have a number of virtues in problems concerning crack growth and propagation, strain localization, dynamic shear band propagation, projectile penetration, among others. The main drawback of such methods is that the resulting matrices are more densely populated and the computational cost for the formulation and solution of the problem is much higher than the conventional FEM. This is the reason for their limited application to academic and small-scale problems until now. In this paper, we introduce a novel approach for reducing the computational cost of meshless element free Galerkin (EFG) methods by employing domain decomposition techniques on the physical as well as on the algebraic domains. Specifically, we propose the implementation of the dual domain decomposition FETI family of methods that have been successfully used with FEM in many problems in computational mechanics. We address the issues of dividing an overlapping meshfree EFG domain to several overlapping subdomains, following the algebraic decomposition of the FETI method and alternatively on non-overlapping subdomains by modifying the required displacement compatibility conditions and by improving the accuracy of the solution through a stress update procedure. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Meshless EFG Domain decomposition FETI solution algorithms

来源：评论

学校读者我要写书评

暂无评论

FINITE ELASTICITY IN SPATIAL DESCRIPTION - LINEARIZATION ASPECTS WITH 3-D MEMBRANE APPLICATIONS

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 1995年第20期38卷 3365-3381页

作者： NETO, EAD PERIC, D OWEN, DRJ Department of Civil Engineering University of Wales Swansea Singleton Park Swansea SA2 8PP U.K.

The treatment of finite hyperelasticity set on the spatial configuration is described. The fully consistent linearization of the corresponding field equations is carried out in detail, It provides the basis of the exact Newton-Raphson procedure for solution of the associated boundary value problem. A membrane formulation is presented in which the incompressibility constraint usually employed in the description of rubber-like materials is satisfied trivially. The excellent performance of the proposed framework is demonstrated by means of 3-D membrane finite element simulations.

关键词： NONLINEAR ELASTICITY FINITE ELEMENTS solution algorithms 3-DIMENSIONAL MEMBRANES

来源：评论

学校读者我要写书评

暂无评论

Analysis of the vibrations of flexible discrete-continuous one-dimensional systems with nonpotential deformation characteristics

引用

INTERNATIONAL APPLIED MECHANICS 2005年第2期41卷 168-173页

作者： Bezverkhii, AI Natl Acad Sci Ukraine SP Timoshenko Inst Mech Kiev Ukraine

An approach is proposed to solve dynamic problems for discrete-continuous flexible one-dimensional systems with nonpotential deformation characteristics. The approach is based on a generalized stationarity principle. The solution algorithm employs cubic spline functions. A numerical example demonstrates the capabilities of this approach in determining the loads and displacements in such a system under external influence.

关键词： discrete-continuous flexible one-dimensional system nonpotential deformation characteristics stationarity principle solution algorithms spline function

来源：评论

学校读者我要写书评

暂无评论

A special three-level optimization problem

引用

JOURNAL OF GLOBAL OPTIMIZATION 2020年第3期76卷 519-531页

作者： Dempe, S. Khamisov, O. Kochetov, Yu. TU Bergakad Freiberg Dept Math & Comp Sci Freiberg Germany Russian Acad Sci Siberian Branch Sobolev Inst Math Novosibirsk Russia Novosibirsk State Univ Novosibirsk Russia

A special linear, three-level optimization problem is considered where the reaction of the third-level decision maker influences the objective functions of both decision makers on the first and the second level via its optimal objective function value. For this problem, existence of an optimal solution as well as its computation are investigated.

关键词： Bilevel optimization Three-level optimization Necessary optimality conditions solution algorithms Hierarchical optimization

来源：评论

学校读者我要写书评

暂无评论

Efficient solutions for a class of optimal stopping problems

引用

OPERATIONS RESEARCH LETTERS 2012年第5期40卷 409-410页

作者： Shechter, Steven M. Univ British Columbia Operat & Logist Div Sauder Sch Business Vancouver BC V6T 1Z2 Canada

We show that a practical class of optimal stopping problems can be solved in at most N iterations of policy iteration. Under a lower triangularity assumption, one iteration of Gauss-Seidel value iteration yields the solution, while a subadditivity assumption implies an optimal control limit policy and an O(log N) algorithm. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Optimal stopping problems Markov decision processes solution algorithms

来源：评论

学校读者我要写书评

暂无评论

AN EFFICIENT MESH UPDATING TECHNIQUE FOR FLUID-STRUCTURE INTERACTION PROBLEMS

引用

INTERNATIONAL JOURNAL OF COMPUTATIONAL METHODS 2007年第2期4卷 249-263页

作者： Mouroutis, Z. S. Markou, G. A. Papadrakakis, M. Charmpis, D. C. Natl Tech Univ Athens Inst Struct Anal & Seism Res GR-15773 Zografos Greece Univ Cyprus Dept Civil & Environm Engn CY-1678 Nicosia Cyprus

The purpose of this paper is to present a robust mesh updating technique combined with an efficient solution algorithm applicable to large-scale fluid-structure interaction problems. We show that a combination of the dimensional torsional spring concept and a preconditioned conjugated gradient type method, for the solution of the "elasticity" problem, provides a powerful tool for this computationally intensive problem.

关键词： Coupled problems solution algorithms mesh updating

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：