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1.
THEINTEGRATIONMETHODSOFVACCODYNAMICSEQUATIONOFNONLINEARNONHOLONOMICSYSTEMLuoShaokai(罗绍凯)(RceeivedAug.2.1993:communicatedbyWan...  相似文献   

2.
变质量非完整系统相对运动动力学方程的积分理论   总被引:1,自引:0,他引:1  
本文研究变质量非线性非完整系统相对于非惯性系动力学的积分理论,给出其Routh降阶法,Whittaker降阶法,Poincare-Cartan型积分变量关系和积分不变量。  相似文献   

3.
This paper presents the generalized principles of least action of variable massnonholonomic nonconservative system in noninertial reference frame, proves theequivalence between Holder form and Suslov form, and then obtains differential equationsof motion of variable mass nonholonomic nonconservative system in noninertial referenceframe.  相似文献   

4.
In this paper,the Kane’s equations for the Routh’s form of variable massnonholonomic systems are established.and the Kane’s equations for percussion motionof variable mass holonomic and nonholonomic systems are deduced from them. Secondly,the equivalence to Lagrange’s equations for percussion motion and Kane’sequations is obtained,and the application of the new equation is illustrated by anexample.  相似文献   

5.
ThesystemofdynamicsconsistsofNparticles,thevectorrlofithparticlemaybeexpressedbythefunctionofthegeneralizedcoordinatesq,andtimeI;itsconfigurationisdeterminedbygeneralizedcoordinatesq,;itisacteduponbygnon-linearnon-hoIonomicconstraints'inoneorder,i.e.j'(q.…  相似文献   

6.
In this paper,Routh’s equations for the mechanical systems of the variable masswith nonlinear nonholonomic constraints of arbitrary orders in a noninertial referencesystem have been deduced not from any variational principles,but from the dynamicalequations of Newtonian mechanics.And then again the other forms of equations fornonholonomic systems of variable mass are obtained from Routh’s equations.  相似文献   

7.
可控变质量非完整系统相对运动方程的积分方法   总被引:1,自引:0,他引:1  
傅景礼 《力学季刊》1998,19(2):163-169
本文给出了积分可控变质量非线性非完整系统的相对于非惯性系动力学方程的梯度法和单分量法。  相似文献   

8.
IntroductionThereisacloserelationbetweenthesymmetryandtheconservedquantityinamechanicalsystem .ModernmethodstofindconservedquantityofamechanicalsystemaremainlyNoethersymmetrymethod[1]andLiesymmetrymethod[2 ].NoethersymmetryisaninvarianceoftheHamiltonactionundertheinfinitesimaltransformations.Liesymmetryisaninvarianceofthedifferentialequationsundertheinfinitesimaltransformations.Inthepasttenyears,aseriesofimportresultshavebeenobtainedonthestudyoftheNoethersymmetryandLiesymmetry[3~12 ].Thefo…  相似文献   

9.
随着科学技术的发展,对喷气飞机、火箭等变质量系统动力学的研究显得越来越重要, 并且总是希望变质量系统的解是稳定的或渐近稳定的. 而通用的研究稳定性的Lyapunov直接法有很大难度, 因为直接从微分方程出发构造Lyapunov函数往往很难实现. 本文给出一种研究稳定性的间接方法, 即梯度系统方法. 该方法不但能揭示动力学系统的内在结构, 而且有助于探索系统的稳定性、渐进性和分岔等动力学行为. 梯度系统的函数V通常取为Lyapunov函数, 因此梯度系统比较适合用Lyapunov函数来研究. 列写出变质量完整力学系统的运动方程,在系统非奇异情形下,求得所有广义加速度. 提出一类具有负定矩阵的梯度系统, 并研究该梯度系统解的稳定性. 把这类梯度系统和变质量力学系统有机结合,给出变质量力学系统的解可以是稳定的或渐近稳定的条件, 进一步利用矩阵为负定非对称的梯度系统构造出一些解为稳定或渐近稳定的变质量力学系统. 通过具体例子,研究了变质量系统的单自由度运动,在怎样的质量变化规律、微粒分离速度和加力下,其解是稳定的或渐近稳定的. 本文的构造方法也适合其它类型的动力学系统.   相似文献   

10.
非定常非完整力学系统的稳定性研究是重要而又困难的问题,直接从微分方程出发来构造李雅普诺夫函数往往很难实现.本文给出了一种间接方法.提出了10类广义梯度系统的定义,并分别给出了10类广义梯度系统的微分方程.进一步研究一般切塔耶夫型非完整系统的广义梯度表示,给出该系统分别成为这10类广义梯度系统的条件,从而将切塔耶夫型非完整系统化成各类广义梯度系统.最后利用广义梯度系统的性质来研究切塔耶夫型非完整系统零解的稳定性.这种方法在直接构造李雅普诺夫函数发生困难时,显得更为有效.举例说明结果的应用.  相似文献   

11.
A large proportion of constrained mechanical systems result in nonlinear ordinary differential equations, for which it is quite difficult to find analytical solutions. The initial motions method proposed by Whittaker is effective to deal with such problems for various constrained mechanical systems, including the nonholonomic systems discussed in the first part of this paper, where in addition to differential equations of motion, nonholonomic constraints apply. The final equations of motion for these systems are obtained in the form of corresponding power series. Also, an alternative, direct method to determine the initial values of higher-order derivatives \({\ddot{q}}_0 ,{{\dddot{q}{} }}_{\!0} ,\ldots \) is proposed, being different from that of Whittaker. The second part of this work analyzes the stability of equilibrium of less complex, nonholonomic mechanical systems represented by gradient systems. We discuss the stability of equilibrium of such systems based on the properties of the gradient system. The advantage of this novel method is its avoidance of the difficulty of directly establishing Lyapunov functions aimed at such unsteady nonlinear systems. Finally, these theoretical considerations are illustrated through four examples.  相似文献   

12.
Optimizing the dynamic response of mechanical systems is often a necessary step during the early stages of product development cycle. This is a complex problem that requires to carry out the sensitivity analysis of the system dynamics equations if gradient-based optimization tools are used. These dynamics equations are often expressed as a highly nonlinear system of ordinary differential equations or differential-algebraic equations, if a dependent set of generalized coordinates with its corresponding kinematic constraints is used to describe the motion. Two main techniques are currently available to perform the sensitivity analysis of a multibody system, namely the direct differentiation and the adjoint variable methods. In this paper, we derive the equations that correspond to the direct sensitivity analysis of the index-3 augmented Lagrangian formulation with velocity and acceleration projections. Mechanical systems with both holonomic and nonholonomic constraints are considered. The evaluation of the system sensitivities requires the solution of a tangent linear model that corresponds to the Newton–Raphson iterative solution of the dynamics at configuration level, plus two additional nonlinear systems of equations for the velocity and acceleration projections. The method was validated in the sensitivity analysis of a set of examples, including a five-bar linkage with spring elements, which had been used in the literature as benchmark problem for similar multibody dynamics formulations, a point-mass system subjected to nonholonomic constraints, and a full-scale vehicle model.  相似文献   

13.
A field method for solving the equations of motion of nonholonomic systems   总被引:6,自引:0,他引:6  
In this paper, the field method[1] for solving the equations of motion of holonomic nonconservative systems is extended to nonholonomic systems with constant mass and with variable mass. Two examples are given to illustrate its application. The project supported by the National Natural Science Foundation of China.  相似文献   

14.
IntroductionThestudyofsymmetryandconservedquantityofmechanicalsystemisanimportanttopicinmathematics,mechanicsandphysics .ThemoderntheoriesofsymmetryandconservedquantityofmechanicalsystemincludeNoethersymmetrytheoryandLiesymmetrytheory .In 1979M .Lutzkyando…  相似文献   

15.
This paper deals with the forward and the inverse dynamic problems of mechanical systems subjected to nonholonomic constraints. The intrinsically dual nature of these two problems is identified and utilised to develop a systematic approach to formulate and solve them according to an unified framework. The proposed methodology is based on the fundamental equations of constrained motion which derive from Gauss’s principle of least constraint. The main advantage arising from using the fundamental equations of constrained motion is that they represent an effective method capable to derive the generalised acceleration of a mechanical system, constrained in general by a set of nonholonomic constraints, together with the generalized constraint forces (forward dynamics). When the constraint equations are used to represent the desired behaviour of the mechanical system under study, the generalised constraint forces deriving from the fundamental equations of constrained motion provide the control actions which reproduce the specified motion for the system (inverse dynamics). This approach is systematically extended to underactuated mechanical systems introducing a new method named underactuation equivalence principle. The underactuation equivalence principle is founded on the key idea that the underactuation property of a mechanical system can be mathematically represented using a particular set of nonholonomic constraint equations. Two simple case-studies are reported to exemplify the proposed methodology. In the first case-study the computation of the generalised constraint forces relative to the revolute joint constraints of a physical pendulum is illustrated. In the second case-study the calculation of the control action which solves the swing-up problem for an inverted pendulum is described.  相似文献   

16.
The algebraic structure and the Poisson method for a weakly nonholonomic system are studied. The differential equations of motion of the system can be written in a contravariant algebra form and its algebraic structure is discussed. The Poisson theory for the systems which possess Lie algebra structure is generalized to the weakly nonholonomic system. An example is given to illustrate the application of the result.  相似文献   

17.
The form invariance and the conserved quantity for a weakly nonholonomic system (WNS) are studied. The WNS is a nonholonomic system (NS) whose constraint equations contain a small parameter. The differential equations of motion of the system are established. The definition and the criterion of form invariance of the system are given. The conserved quantity deduced from the form invariance is obtained. Finally, an illustrative example is shown.  相似文献   

18.
变质量非完整力学系统的相对运动动力学   总被引:6,自引:0,他引:6  
刘桂林  乔永芬 《力学学报》1989,21(6):742-748
  相似文献   

19.
This paper is concerned with the dynamics of a mechanical system subject to nonintegrable constraints. In the first part, we prove the equivalence between the classical nonholonomic equations and those derived from the nonholonomic variational formulation, proposed by Kozlov in [10–12], for a class of constrained systems with constraints transverse to a foliation. This result extends the equivalence between the two formulations, proved for holonomic constraints, to a class of linear nonintegrable ones. In the second part, we derive the nonholonomic variational reduced equations for a constrained system with symmetry and constraint transverse to a principal bundle fibration, using a reduction procedure similar to the one developed in [5]. The resulting equations are compared with the nonholonomic reduced ones through mechanical examples.  相似文献   

20.
WHITTAKER'SREDUCTIONMETHODFORPOINCARE'sDYNAMICALEQUATIONSQ.K.Ghori(DepartmentofMathematicalSciences,KingFahdUniversityofPetro...  相似文献   

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