The motion characteristics of the double‐pendulum system with skew walls

Many components of machines and other technological devices (chains and bodies hanging on the ropes) can be modeled as multiple pendulums situated in tubes or holes of limited space. The investigation of motion of such systems represents the substance of many real technological problems; therefore, it stirred up motivation to perform research on vibration of a double pendulum situated between two skew rigid walls. The analyzed system was set into motion by the horizontal movement of its suspending. The results of the simulations show that the system can exhibit both the regular and chaotic movements depending on the excitation frequency. The development of the computational model, which is applicable for more complex investigations, and learning more on the motion character of a double pendulum, the movement of which is limited by skew walls, are the principal contributions of the presented article.     

二维Lengyel-Epstein模型的六边形斑图

从局部分支的观点讨论2维Lengyel-Epstein模型的非常数正平衡态问题. 首先, 当区域为矩形时用局部分支定理构造六边形平衡态斑图; 其次, 在分支点附近确定分支方向.     

Stability of laminated convex shells of revolution with microdamages in laminate components

The problem of bifurcation instability of shells of revolution made of a laminate material with progressively damaged components under loading is formulated and solved __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 7, pp. 98–106, July 2006.     

ON THE COEFFICIENTS APPEARING IN THE EXPANSION OF MELNIKOV FUNCTIONS IN HOMOCLINIC BIFURCATIONS

Ｃｏｎｓｉｄｅｒａｐｌａｎａｒｐｅｒｔｕｒｂｅｄｓｙｓｔｅｍｏｆｔｈｅｆｏｒｍｘ＝Ｈｙ＋εｆ（ｘ，ｙ），ｙ＝－Ｈｘ＋εｇ（ｘ，ｙ）（１）ｗｈｅｒｅＨ，ｆ，ｇａｒｅｆｕｎｃｔｉｏｎｓｏｆｃｌａｓＣ∞．Ａｓｕｍｅｆｏｒε＝０（１）ｔｏｈａｖｅａｈｏｍｏｃ...     

On the Bifurcation of Flows of a Heat-Conducting Fluid between Two Rotating Permeable Cylinders

Sufficient conditions are found for the bifurcation of flow of a viscous heat-conducting fluid between two rotating permeable cylinders.     

The discussion about horseshoes and finite subharmonic bifurcations

In this paper, finite subharmonic bifurcations have been discussed by means of some examples. It is found that for centrally symmetric system, under small disturbance, if it has two independant sequences of subharmonic bifurcations, the system passes to chaos (horeseshoe) through finite subharmonic bifurcations, and that for noncentrally symmetric system, the relation between subharmonic bifurcations and horseshoe is complicated.     

Hopf-Takens bifurcations and centres

The paper deals with Hopf-Takens bifurcations, both in generic families and in families containing centres. Attention goes to the relation between normal forms, Lyapunov coefficients and the Bautin ideal. In case the Bautin ideal has only one generator we pay attention to the first non-zero Melnikov function.     

Pathways to hopf bifurcations in dynamic continuous-time optimization problems

The purpose of this paper is to characterize pathways to Hopf bifurcation in continuous time, concave, two-dimensional optimal control models. It is shown that essentially two pathways exist: control-state interaction and growth. The knowledge of such pathways provides a criterion at the stage of modelling on the potential complexity of optimal trajectories.The author knowledges the many discussions with Professor Gustav Feichtinger.     

BIFURCATION OF SINGULAR POINTS NEAR A DOUBLE FOLD POINT INZ_2 -SYMMETRIC NONLINEAR EQUATIONS

We consider the bifurcation of singular points near a double fold point in Z2 -symmetric nonlinear equations with two parameters,where the linearization has a two dimensional null space spanned by a symmetric null vector and an ami-symmetric null vector. In particular, we show the existence of a turning point path and a pitchfork point path passing ihrough the double fold point and they are the only singular points nearby. Their nondegeneracy is confirmed. A supporting numerical example is also provided. The main tools for our analysis as well as the compulation are some extended systems.     

Eigenvalues of the discretized Navier-Stokes equation with application to the detection of Hopf bifurcations

This paper is concerned with a numerical approach to the problem of finding the leftmost eigenvalues of large sparse nonsymmetric generalised eigenvalue problems which arise in stability studies of incompressible fluid flow problems. The matrices have a special block structure that is typical of mixed finite element discretizations for such problems. The numerical approach is an extension of the hybrid technique introduced by Saad [22] and utilizes the idea of preconditioning the eigenvalue problem before applying Arnoldi's method. Two preconditioners, one a modified Cayley transform, the other a Chebyshev polynomial transform, are compared in numerical experiments on a double diffusive convection problem and the Cayley transform proves superior. The Cayley transform is then used to provide numerical results for the finite Taylor problem.