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IntroductionTheporousmediamodelsdeducedfrommixturetheoryareattractingattentionofmoreandmoreresearchersbecauseitisbasedontheframeofcontinuummechanics[1]andweresuccessfullyusedtodepictthemechanicalbehaviorsofsoilsandbiologicalsofttissues[2 ,3].Withthistypeo… 相似文献
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STUDIES OF MELNIKOV METHOD AND TRANSVERSAL HOMOCLINIC ORBITS IN THE CIRCULAR PLANAR RESTRICTED THREE-BODY PROBLEM 总被引:1,自引:0,他引:1
STUDIES OF MELNIKOV METHOD AND TRANSVERSAL HOMOCLINIC ORBITS IN THE CIRCULAR PLANAR RESTRICTED THREE-BODY PROBLEMZhuRuzeng(朱如... 相似文献
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采用有限元法中的伪弧长算法研究了集中载荷作用下圆拱的大范围非线性问题,给出了临界载荷与圆心角间的关系曲缄以及极值分叉与简单分叉的分界点,并对屈曲后的变形进行了追踪,文中首先简述伪弧长算法,然后给出了计算结果。 相似文献
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A finite element method for highly viscous fluid is used to calculate the velocity and stress fields in the surrounding soft
rock of a tunnel. In order to fit the calculated values with the measured displacement of tunnel wall, we inverted the boundary
forces and the mechanical parameters of the surrounding rocks. 相似文献
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The Newtonian circular restricted four-body problem is considered. We obtain nonlinear algebraic equations determining equilibrium
solutions in the rotating frame and find six possible equilibrium configurations of the system. Studying the stability of
equilibrium solutions, we prove that the radial equilibrium solutions are unstable, while the bisector equilibrium solutions
are stable in Lyapunov’s sense if the mass parameter satisfies the conditions μ ∈ (0, μ0, where μ0 is a sufficiently small number, and μ ≠ μj, j = 1, 2, 3. We also prove that, for μ = μ1 and μ = μ3, the resonance conditions of the third order and the fourth order, respectively, are satisfied and, for these values of μ,
the bisector equilibrium solutions are unstable and stable in Lyapunov’s sense, respectively. All symbolic and numerical calculations
are done with the Mathematica computer algebra system.
Published in Neliniini Kolyvannya, Vol. 10, No. 1, pp. 66–82, January–March, 2007. 相似文献
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On the basis of the stepped reduction method suggested in [1], we investigate the problem of the bending of elastic circular
ring of non-homogeneous and variable cross section under the actions of arbitrary loads. The general solution of this problem
is obtained so that it can be used for the calculations of strength and rigidity of practical problems such as arch, tunnel
etc. In order to examine results of this paper and explain the application of this new method, an example is brought out at
the end of this paper.
Circular ring and arch are commonly used structures in engineering. Timoshenko, S.[2], Barber, J. R.[3], Tsumura Rimitsu[4] et al. have studied these problems of bending, but, so far as we know, it has been solely restricted to the general solution
of homogeneous uniform cross section ring. The only known solution for the problems with variable cross section ones has been
solely restricted to the solution of special case of flexural rigidity in linear function of coordinates. On account of fundamental
equations of the non-homogeneous variable cross section problem being variable coefficients, it is very difficult to solve
them. In this paper, we use the stepped reduction method suggested in [1] to transform the variable coefficient differential
equation into equivalent constant coefficient one. After introducing virtual internal forces, we obtain general solution of
an elastic circular ring with non-homogeneity and variable cross section under the actions of arbitrary loads. 相似文献
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Martin Kummer Richard C. Churchill 《Journal of Dynamics and Differential Equations》1997,9(2):249-268
This paper presents a new derivation of the twist mapping in the planar restricted problem. It differs from other treatments in the use of a novel canonical transformation which allows for the utilization of symplectic reduction techniques. 相似文献
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利用辛解析奇异单元,结合时域精细算法,研究了动荷载作用下的含平面V型切口问题。时域上,采用时域精细算法,并结合自适应算法控制展开项数,保证了计算精度。空间域上,切口尖端附近采用辛解析奇异单元,其余区域采用常规有限单元,避免了局部网格加密。本文使用的辛解析奇异单元不需要过渡单元和局部网格加密,且能够通过奇异单元内部的参数关系直接给出切口尖端的应力强度因子,不需要复杂的后处理过程。数值结果表明,本文方法具有良好的精度和稳定性,可以准确地计算动态应力强度因子。 相似文献
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The problem of hydraulic fracture formation in a porous medium is investigated in the approximation of small fracture opening and inertialess incompressible Newtonian fluid fracture flow when the seepage through the fracture walls into the surrounding reservoir is asymptotically small or large. It is shown that the system of equations describing the propagation of the fracture has self-similar solutions of power-law or exponential form only. A family of self-similar solutions is constructed in order to determine the evolution of the fracture width and length, the fluid velocity in the fracture, and the length of fluid penetration into the porous medium when either the fluid flow rate or the pressure as a power-law or exponential function of time is specified at the fracture entrance. In the case of finite fluid penetration into the soil the system of equations has only a power-law self-similar solution, for example, when the fluid flow rate is specified at the fracture entrance as a quadratic function of time. The solutions of the self-similar equations are found numerically for one of the seepage regimes. 相似文献
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Thedynamictransientresponseanalysisofporousmediaplaysaveryimportantroleinalotofengineeringpracticessuchastransientconsolidation,noisecontrol,earthquakeengineeringandbioengineering.Biot[1]originallydiscussedthewavepropagationprobleminfluid_saturatedpo… 相似文献
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孙右烈 《应用数学和力学(英文版)》1988,9(1):51-60
In order to solve the problem of motion for the system with n degrees of freedom under the action of p impulsive constraints, we must solve the simultaneous equations consisting of n+p equations. In this paper, it has been shown that the undetermined multipliers in the equations of impact can be cancelled for the cases of both the generalized coordinates and the quasi-coordinates. Thus there are only n-p equations of impact. Combining these equations with p impulsive constraint equations, we have simultaneous equations consisting of n equations. Therefore, only n equations are necessary to solve the problem of impact for the system subjected to impulsive constraints. The method proposed in this paper is simpler than ordinary methods. 相似文献
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A. V. Kuznetsov 《Applied Scientific Research》1996,56(1):53-67
In this paper analytical solutions for the steady fully developed laminar fluid flow in the parallel-plate and cylindrical channels partially filled with a porous medium and partially with a clear fluid are presented. The Brinkman-extended Darcy equation is utilized to model the flow in a porous region. The solutions account for the boundary effects and for the stress jump boundary condition at the interface recently suggested by Ochoa-Tapia and Whitaker. The dependence of the velocity on the Darcy number and on the adjustable coefficient in the stress jump boundary condition is investigated. It is shown that accounting for a jump in the shear stress at the interface essentially influences velocity profiles. 相似文献
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非饱和多孔介质有限元分析的基本控制方程与变分原理 总被引:2,自引:1,他引:2
本文在对问题研究现状进行阐述的基础上较系统地给出了骨架可变形非饱和多孔介质的全耦合分析模型,模型中考虑了孔隙气体,水(油)流动对介质力学性能的影响,多孔介质的饱和度,渗透系数与毛吸压力的关系,由实验给出,所导出的控制方程以固体骨架的位移与孔隙流体压力为基本未知量,由于问题的非自共轭特征,文中构造了非饱和介质动力问题的参数变分形式,并在此基础上给出有限元离散方程。 相似文献
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李骊 《应用数学和力学(英文版)》1983,4(5):667-680
In this paper the problem of the stability of rotational motion of a rigid body which has a liquid filled cavity and a fixed
point is investigated without any approximation. Criteria of stability and instability under finite disturbance are obtained.
The region of stability is found out explicitly. 相似文献