检索结果-内蒙古大学图书馆

An adaptive semi-explicit/explicit time marching technique for nonlinear dynamics

COMPUTER methods IN APPLIED MECHANICS AND ENGINEERING 2019年 354卷 637-662页

作者： Soares Jr, Delfim Univ Fed Juiz de Fora Struct Engn Dept Juiz De Fora MG Brazil

In this work, an entirely automatized adaptive semi-explicit/explicit numerical approach is proposed to analyse nonlinear dynamic models. In this methodology, the time integrators are spatially and temporally locally evaluated, allowing different values to be assigned to each element of the spatial discretization and to each time step of the analysis. Thus, a very flexible procedure is enabled, permitting the technique to properly locally adapt to the properties of the model, as well as to the computed results. The novel algorithm is very accurate and extremely efficient, since it deals with reduced systems of equations and it requires no iterative procedures for solution. The main features of the novel methodology can be summarized as follows: (i) it is simple;(ii) it is locally defined;(iii) it enables stabilized analyses;(iv) it is an efficient non-iterative single-solution procedure;(v) it provides enhanced accuracy;(vi) it enables advanced controllable algorithmic dissipation in the higher modes;(vii) it considers a link between the temporal and the spatial discretizations;(viii) it stands as a single-solve framework based on reduced systems of equations;(ix) it provides an updating criterion for the tangent nonlinear matrices;(x) under special conditions, it may reproduce the Central Difference Method;(xi) it is entirely automated, requiring no expertise from the user. (C) 2019 Elsevier B.V. All rights reserved.

关键词： time integration methods Explicit analysis Local formulations Adaptive parameters Stability Nonlinear dynamics

来源：评论

学校读者我要写书评

暂无评论

A Simple Explicit-Implicit time-Marching Technique for Wave Propagation Analysis

引用

INTERNATIONAL JOURNAL OF COMPUTATIONAL methods 2019年第1期16卷

作者： Soares Jr, Delfim Univ Fed Juiz de Fora Struct Engn Dept BR-36036330 Juiz De Fora MG Brazil

A new explicit-implicit time integration technique is proposed here for wave propagation analysis. In the present formulation, the time integrators of the model are selected at the element level, allowing each element to be considered as explicit or implicit. In the implicit elements, controllable algorithm dissipation is provided, enabling an L-stable formulation. In the explicit elements, null amplitude decay is considered, enabling maximal critical time-step values. The new methodology renders a very simple and effective time-marching algorithm. Here, just displacement velocity relations are considered, and no computation of accelerations is required. Moreover, explicit/implicit analyses can be carried out just by the tuning of local effective matrices, inputting or not stiffness matrices into their computations. At the end of the paper, numerical results are presented, illustrating the performance and potentialities of the new method.

关键词： time integration methods explicit-implicit analysis dissipation control stability accuracy wave propagation

来源：评论

学校读者我要写书评

暂无评论

Development of a direct time integration method based on Bezier curve and 5th-order Bernstein basis function

引用

COMPUTERS & STRUCTURES 2018年 194卷 15-31页

作者： Malakiyeh, Mohammad Mandi Shojaee, Saeed Javaran, Saleh Hamzehei Kerman Azad Univ Dept Civil Engn Kerman Iran Shahid Bahonar Univ Dept Civil Engn Kerman Iran

In this study, a robust unconditionally stable method for linear analysis of structures based on Bezier curves and Bernstein polynomials is proposed. The Bezier curve is used as interpolation function and Bernstein basis functions are applied for interpolation. The spectral radius, period elongation and amplitude decay are investigated for stability analysis, numerical dispersion and dissipation of proposed method, and results are compared with other methods that are the best in these properties. It is also shown that the behavior of the proposed method in analysis of finite element system is effective and reliable. To show the robustness and features of proposed method, a challenging problem with a very stiff and flexible response, a Howe truss under impact load, a frame under harmonic loading and a rectangular domain in plane strain condition are considered, and derived results are compared with references solutions and other results reported in the literature. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： time integration methods Structural dynamics Unconditional stability Bernstein basis functions Bezier curves

来源：评论

学校读者我要写书评

暂无评论

Insight into an implicit time integration method based on Bezier curve and third-order Bernstein basis function for structural dynamics

引用

Asian Journal of Civil Engineering 2018年第1期19卷 1-11页

作者： Malakiyeh, Mohammad Mahdi Shojaee, Saeed Hamzehei Javaran, Saleh Department of Civil Engineering Kerman Azad University Kerman Iran Department of Civil Engineering Shahid Bahonar University Kerman Iran

In this paper, an implicit time integration method based on Bezier curves and Bernstein polynomials for analysis of structures is presented. Unconditional stability and accuracy comparable to other methods such as Newmark with high numerical damping to suppress spurious participation of the higher modes are the features of the proposed method that are demonstrated in stability and accuracy analyses. To show the efficiency and validity of presented method, three numerical examples are considered. A simple step-by-step algorithm is also provided for the proposed method. © 2017, Springer International Publishing AG.

关键词： Bernstein basis functions Bezier curves Structural dynamics time integration methods Unconditional stability

来源：评论

学校读者我要写书评

暂无评论

A simple and effective single-step time marching technique based on adaptive time integrators

引用

INTERNATIONAL JOURNAL FOR NUMERICAL methods IN ENGINEERING 2017年第9期109卷 1344-1368页

作者： Soares, Delfim Univ Fed Juiz de Fora Dept Struct Engn BR-36036330 Juiz De Fora MG Brazil

In this work, a novel time marching procedure is presented in which adaptive time integration parameters are locally computed, allowing different spatial and temporal distributions. As a consequence, a more versatile technique arises, enabling an enhanced performance. The main features of the proposed technique are: (1) it is simple;(2) it has guaranteed stability;(3) it is an efficient non-iterative adaptive single-step procedure;(4) it provides enhanced accuracy;(5) it enables advanced controllable algorithmic dissipation in the higher modes;(6) it is truly self-starting;and (7) it is entirely automatic, requiring no input parameter from the user. The proposed technique is very complete, providing the main positive attributes that are requested from an effective time marching procedure. Numerical results are presented along the paper, illustrating the excellent performance of the method. Copyright (c) 2016 John Wiley & Sons, Ltd.

关键词： time integration methods adaptive parameters hyperbolic models accuracy stability dissipation control

来源：评论

学校读者我要写书评

暂无评论

An implicit family of time marching procedures with adaptive dissipation control

引用

APPLIED MATHEMATICAL MODELLING 2016年第4期40卷 3325-3341页

作者： Soares, Delfim Univ Fed Juiz de Fora Dept Struct Engn BR-36036330 Juiz De Fora MG Brazil

In this work, an unconditionally stable family of time marching procedures is proposed, in which the time integration parameters of the method are locally computed, considering the properties of the model. Thus, the technique adapts to the characteristics of the problem, enabling enhanced analyses. Here, adaptive dissipation control is explored, allowing spurious modes to be more effectively dissipated. The proposed technique is second-order accurate, L stable, truly self-starting and very easy to implement. Numerical results are presented along the paper, illustrating the good performance of the novel single-step technique. (C) 2015 Elsevier Inc. All rights reserved.

关键词： time integration methods Dissipation control High frequency behavior Stability Accuracy Dynamics

来源：评论

学校读者我要写书评

暂无评论

A novel family of explicit time marching techniques for structural dynamics and wave propagation models

引用

COMPUTER methods IN APPLIED MECHANICS AND ENGINEERING 2016年 311卷 838-855页

作者： Soares, Delfim, Jr. Univ Fed Juiz de Fora Dept Struct Engn BR-36036330 Juiz De Fora MG Brazil

In this work, a novel family of explicit time marching techniques is presented, for hyperbolic models. The main features of the proposed procedure are: (i) the family is based only on single-step displacement-velocity relations, being very simple to implement;(ii) as usual in explicit analyses, it requires no system of equations to be dealt with, being very efficient;(iii) it is truly self-starting;(iv) it is second-order accurate;(v) it enables controllable algorithmic dissipation in the higher modes;(vi) it provides reduced period elongation errors in the lower modes;(vii) it is conditionally stable and exhibits high stability limits, with its critical sampling frequency varying between 3.571 and 4 (i.e., its upper limit is twice that of the Central Difference Method). The proposed technique is very effective, providing the main positive attributes that are requested from an efficacious explicit time marching procedure. Numerical results are presented along the paper, illustrating the excellent performance of the novel method. (C) 2016 Elsevier B.V. All rights reserved.

关键词： time integration methods Explicit analysis Hyperbolic models Accuracy Stability Dissipation control

来源：评论

学校读者我要写书评

暂无评论

A simple and effective new family of time marching procedures for dynamics

引用

COMPUTER methods IN APPLIED MECHANICS AND ENGINEERING 2015年 283卷 1138-1166页

作者： Soares, Delfim, Jr. Univ Fed Juiz de Fora Dept Struct Engn BR-36036330 Juiz De Fora MG Brazil

In this work, a new family of time-marching procedures for dynamics is introduced. The proposed algorithm is based on displacements-velocities relations, requiring no computation of accelerations. Thus, not only it is a very simple technique, but also it is truly self-starting. Unconditionally stable implicit and conditionally stable explicit approaches are focused here, and optimized procedures are discussed for these analyses. The new technique is second-order accurate with controllable period elongation and algorithmic dissipation. Numerical results are presented, illustrating the good performance of the method. The new family is simple, efficient and highly accurate, resulting in a very effective time-marching technique. (C) 2014 Published by Elsevier B.V.

关键词： time-marching time integration methods Dynamics Accuracy Stability

来源：评论

学校读者我要写书评

暂无评论

A reduced integration method for the coupled analysis of floating production systems

引用

OCEAN ENGINEERING 2015年 104卷 422-436页

作者： Correa, Fabricio Nogueira Jacovazzo, Bruno Martins Alves de Lima, Mauro Henrique, Jr. Jacob, Breno Pinheiro Univ Fed Rio de Janeiro Dept Civil Engn LAMCSO Lab Comp Methods & Offshore Syst PEC COPPE UFRJ Post Grad Inst BR-21941596 Rio De Janeiro RJ Brazil

This work presents a reduced integration method for the nonlinear coupled analysis of floating production systems, combining a "strong coupling" formulation with a variation of the Ritz-Wilson basis reduction technique. This leads to an uncoupled formulation for the reduced equations of motion, which may be solved analytically by the Duhamel integral expressing the convolution of the Green functions. These equations are implemented in a recursive time-domain step-by-step solution procedure where the convolution integrals are calculated numerically, with the range of the integration being simply the time step At. The method is tailored for the particular characteristics of the nonlinear dynamic behavior of FPS, including the selection of time steps between basis reevaluations: they are triggered according to the natural periods of the horizontal motions. The results from the case studies indicate that the goal of obtaining an efficient solution method has been reached, allowing an accurate evaluation of the response with lower computational costs. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Floating production systems Coupled analysis Nonlinear dynamics time integration methods

来源：评论

学校读者我要写书评

暂无评论

Defect-based local error estimators for high-order splitting methods involving three linear operators

引用

NUMERICAL ALGORITHMS 2015年第1期70卷 61-91页

作者： Auzinger, Winfried Koch, Othmar Thalhammer, Mechthild Vienna Univ Technol Inst Anal & Sci Comp A-1040 Vienna Austria Univ Innsbruck Inst Math A-6020 Innsbruck Austria

Prior work on high-order exponential operator splitting methods is extended to evolution equations defined by three linear operators. A posteriori local error estimators are constructed via a suitable integral representation of the local error involving the defect associated with the splitting solution and quadrature approximation via Hermite interpolation. In order to prove asymptotical correctness, a multiple integral representation involving iterated defects is deduced by repeated application of the variation-of-constant formula. The error analysis within the framework of abstract evolution equations provides the basis for concrete applications. Numerical examples for initial-boundary value problems of Schrodinger and of parabolic type confirm the asymptotical correctness of the proposed a posteriori error estimators.

关键词： Linear evolution equations time integration methods High-order exponential operator splitting methods Local error A posteriori local error estimators

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：