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基于向量机(vectorcomputers)和并行机(parallelcomputers)两大类并行计算机,对线性静力和动力问题,非线性静力和动力问题,本文概说了相应于这两大类并行机一般的求解方法。 相似文献
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J. C. Simo T. A. Posbergh J. E. Marsden 《Archive for Rational Mechanics and Analysis》1991,115(1):61-100
Communicated by P.Holmes 相似文献
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Dr. Evan Mitsoulis 《Rheologica Acta》1996,35(6):525-530
Professor T. C. Papanastasiou's contributions to rheology and computational fluid mechanics are numerous and have a lasting effect. In the short span of a professional career of about 10 years, and in such diverse places as the University of Minnesota, the University of Michigan, and the Aristotle University of Thessaloniki, he developed and implemented new ideas in the fields of rheology and computational fluid mechanics. He dealt with such important topics as: i) modelling of viscoelasticity and viscoplasticity through appropriate constitutive equations; ii) numerical techniques based on the finite element method, streamline integration, inverse of the unknown, and Newton iteration for integral-differential equations; iii) numerical simulation of important polymer processes, such as fiber spinning, film blowing, film casting, extrusion and coextrusion of polymeric liquids; iv) stability analysis of multiple flows; v) three-dimensional computational techniques for generalized Newtonian flows; vi) numerical analysis of viscoplastic flows; vii) solidification problems; viii) outflow boundary conditions, etc.His many contributions include authoring two books in the area of fluid mechanics, one for undergraduate and the other for graduate use. He was a mentor and an advisor to a dozen people, his former students, who have, in their own right, successful careers, some as professors, others as research engineers in major industries. The ideas and foundations of his work are currently pursued and studied by many researchers world-wide, and in this manner it is the most appropriate tribute to him and a guarantee that his name will be remembered for years to come.Dedicated to the memory of Professor Tasos C. Papanastasiou 相似文献
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A.J.M. Spencer 《International Journal of Solids and Structures》1974,10(10):1103-1123
The boundary layer method proposed by Everstine and Pipkin for the analysis of highly anisotropic materials, such as fibre-reinforced materials, in elastic plane strain is developed and extended also to include plane stress. It is applied to problems of point forces acting on half-planes, and to two crack problems. The boundary layer solutions are compared with known exact solutions in anisotropic elasticity, and it is found that the boundary layer theory gives good results for elastic constants typical of a carbon fibre reinforced resin. 相似文献
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IntroductionTheboundaryelementmethod(BEM)providesanattractivealternativefortheanalysisofengineeringproblems.Itsmainadvantagesareeconomicalandparticularlyconvenientforunboundeddomainandstressconcentrationproblems.Theboundaryintegralequation(BIE)isthe… 相似文献
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武建勋 《应用数学和力学(英文版)》1991,12(4):345-354
In this paper,a new mathematical form,matrix,continued fraction(MCF)isintroduced to describe the decay of effects of an equilibrant system of forces acting on asphere of an elastic body.By this way,the famous Saint-Venant’s principle is proved oftenbut not always valid in computational mechanics. 相似文献
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The development of computational welding mechanics (CWM) began more than four decades ago. The approach focuses on the region outside the molten pool and is used to simulate the thermo-metallurgical-mechanical behaviour of welded components. It was applied to additive manufacturing (AM) processes when they were known as weld repair and metal deposition. The interest in the CWM approach applied to AM has increased considerably, and there are new challenges in this context regarding welding. The current state and need for developments from the perspective of the authors are summarised in this study. 相似文献
12.
Yuan Si 《Acta Mechanica Sinica》1991,7(3):283-288
In this paper, a number of ordinary differential equation (ODE) conversion techniques for transformation of nonstandard ODE
boundary value problems into standard forms are summarised, together with their applications to a variety of boundary value
problems in computational solid mechanics, such as eigenvalue problem, geometrical and material nonlinear problem, elastic
contact problem and optimal design problems through some simple and representative examples. The advantage of such approach
is that various ODE boundary value problems in computational mechanics can be solved effectively in a unified manner by invoking
a standard ODE solver.
The project is supported by National Natural Science Foundation of China. 相似文献
13.
A. A. Schwab 《Journal of Elasticity》1995,41(3):151-160
The paper is concerned with the application of the boundary integral equation method for the holomorphic vector to nonclassical problems in the static theory of elasticity. Problems are considered for the case when on part of a body conditions are overvalued, i.e. the vectors of displacements and loads are prescribed, and on the other part of the body conditions are unknown (so-called (u, p) problem). It is shown that the method proposed is efficient and can be applied to the problems of computer defectoscopy in stationary potential fields. 相似文献
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金属材料计算微观力学网格自动生成 总被引:2,自引:0,他引:2
金属材料微观结构形态不仅在材料科学中具有重要研究意义,而且也是微、细观力学分析,特别是计算微观力学的研究内容。本文依据冶金物理学理论基础,简化材料微结构形成过程,把数学和几何学结合起来,提出了“随机投放,逐点扫描”构造材料微结构形态的方法,并将此方法的仿真结果进行统计分析,用材料物理概念予以检验,表明仿真结果不丢失晶粒形状、晶粒度等主要统计特征,与真实材料的微结构有良好的一致性。 相似文献
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The constraint of a thin silver interlayer is used to create high triaxial stresses to evaluate the applicability of theoretical models for ductile fracture. Rice and Tracey's model for cavity expansion under high triaxial states of stress and Huanget al.'s model for cavity instability were considered. The experimentally determined
m
/
y
values suggest that further investigation of the Huanget al. theory is warranted. Microstructural analysis revealed that multiple cavities were initially present in the silver interlayers, and the number and size of the cavities increased as failure was approached. Finite element analysis and experimental results showed excellent agreement in a computational determination of cavity instability. Thus, it appears that ductile fracture in constrained thin interlayers can be explained with unstable cavity growth. 相似文献
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Leonid K. Antanovskii 《Meccanica》1990,25(4):239-245
Summary In this paper the motion of a viscous multiphase liquid occupying all the space under the action of surface tension is considered. Applying the quasisteady approximation, i.e. when mass forces including inertia terms are neglected, the flow is completely defined by the location of an interface for which the abstract Cauchy problem with nonlocal normal velocity operator is formulated. In order to obtain this operator a standard auxiliary problem for the Stokes system is to be solved which can be reduced to the Fredholm boundary integral equations by means of the application of the hydrodynamic potentials of simple layers. The stability problem of a spherical drop drift is investigated as an illustration of this method.
Sommario Si studia il moto di un liquido viscoso a più fasi che occupa l'intero spazio ed è soggetto all'azione della tensione superficiale. Applicando l'approssimazione quasistazionaria (ossia trascurando forze di massa e termini di inerzia) il flusso è determinato dalla posizione di un'interfaccia per la quale viene formulato un problema di Cauchy astratto con operatore di velocità normale non locale. Per la definizione di questo operatore viene risolto un problema ausiliario standard per il sistema di Stokes, che può essere ridotto ad un'equazione integrale di contorno del tipo Fredholm, facendo uso della rappresentazione in semplice strato del potenziale idrodinamico. Come illustrazione del metodo viene trattato il problema della stabilità di una goccia sferica.相似文献
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The model of structural interfaces developed in Part I of this paper allows us to analytically attack and solve different problems of stress concentration and composites. In particular, (i) new formulae are given for effective properties of composite materials containing dilute suspensions of (randomly oriented) reinforced elliptical voids or inclusions; (ii) a new definition is proposed for inclusion neutrality (to account for the fact that the matrix is always ‘overstressed’, and thus non-neutral in a classical sense, at the contacts with the interfacial structure), which is shown to provide interesting stress optimality conditions. More generally, it is shown that the incorporation of an interfacial structure at the contact between two elastic solids exhibits properties that cannot be obtained using the more conventional approach of the zero-thickness, linear interface. For instance: contrary to the zero-thickness interface, both bulk and shear effective moduli can be optimized for a structural interface; effective properties higher that those possible with a perfect interface can be attained with a structural interface; and neutrality holds with a structural interface for a substantially broader range of parameters than for a zero-thickness interface. 相似文献
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Yu. F. Golubev 《Moscow University Mechanics Bulletin》2009,64(1):1-7
The Okhotsimskii method for the differentiation of functionals in control theory is discussed on the basis of the Pontryagin formalism. The relation of this method to other approaches to solving control problems and to other methods of analytical mechanics is studied. Some typical cases of solving optimal control problems are considered. The brachistochrone problem is solved with consideration of viscous friction. 相似文献
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Leonid K. Antanovskii 《Meccanica》1991,26(2-3):59-65
In this paper planar viscous flows with a free boundary are further studied using the quasisteady approximation [1]. The introduction of the bianalytical stress-stream function provides an opportunity to adopt the theory of analytical functions. The mode of construction of the Fredholm boundary integral equations is here proposed through the explicit solutions of two Hilbert problems for holomorphic functions with the application of the conformal mappings. The stabiligy of the equilibrium of the annulus liquid layer is investigated by way of example.
Sommario Si prosegue lo studio di flussi piani viscosi con frontiera libera applicando l'approssimazione quasistazionaria [1]. L'introduzione della funzione stress-stream bianalitica consente l'uso della teoria delle funzioni olomorfe. La costruzione delle equazioni integrali di Fredholm al contorno proposta qui si basa sulla risoluzione esplicita di due problemi di Hilbert per funzioni analitiche mediante applicazione della tecnica delle trasformazioni conformi. Come esempio si studia la stabilità dell'equilibrio di uno strato liquido anulare.相似文献
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《力学快报》2020,10(2):98-115
This paper first reviews the application research works of wavelet transform on the fluid mechanics. Then the theories of continuous wavelet transform and multi-dimensional orthogonal(discrete) wavelet transform, including wavelet multiresolution analysis, are introduced. At last the applications of wavelet transform on 2 D and 3 D turbulent wakes and turbulent boundary layer flows are described based on the hot-wire, 2 D particle image velocimetry(PIV) and 3 D tomographic PIV. 相似文献