THERMOELASTICITY ANALYSIS OF FINITE COMPOSITE LAMINATES WEAKENED BY MULTIPLE ELLIPTICAL HOLES

ＴＨＥＲＭＯＥＬＡＳＴＩＣＩＴＹＡＮＡＬＹＳＩＳＯＦＦＩＮＩＴＥＣＯＭＰＯＳＩＴＥＬＡＭＩＮＡＴＥＳＷＥＡＫＥＮＥＤＢＹＭＵＬＴＩＰＬＥＥＬＬＩＰＴＩＣＡＬＨＯＬＥＳＸｕＸｉ－ｗｕ（许希武）ＳｕｎＬｉａｎｇ－ｘｉｎ（孙良新）ＦａｎＸｕ－ｑｉ（范绪箕）...     

GREEN＇S FUNCTIONS OF TWO－DIMENSIONAL ANISOTROPIC BODY WITH A PARABOLIC BOUNDARY

ＧＲＥＥＮ＇ＳＦＵＮＣＴＩＯＮＳＯＦＴＷＯ－ＤＩＭＥＮＳＩＯＮＡＬＡＮＩＳＯＴＲＯＰＩＣ ＢＯＤＹ ＷＩＴＨ Ａ ＰＡＲＡＢＯＬＩＣ ＢＯＵＮＤＡＲＹ（胡元太）（赵兴华）ＧＲＥＥＮ＇ＳＦＵＮＣＴＩＯＮＳＯＦＴＷＯ－ＤＩＭＥＮＳＩＯＮＡＬＡＮＩＳＯＴＲＯＰ?..     

ELEMENT－BY－ELEMENT MATRIX DECOMPOSITION ANDSTEP－BY－STEP INTEGRATION METHOD FOR TRANSIENTDYNAMIC PROBLEMS

ＥＬＥＭＥＮＴ－ＢＹ－ＥＬＥＭＥＮＴＭＡＴＲＩＸＤＥＣＯＭＰＯＳＩＴＩＯＮＡＮＤＳＴＥＰ－ＢＹ－ＳＴＥＰＩＮＴＥＧＲＡＴＩＯＮＭＥＴＨＯＤＦＯＲＴＲＡＮＳＩＥＮＴＤＹＮＡＭＩＣＰＲＯＢＬＥＭＳＷａｎｇＨｕａｉｚｈｏｎｇ（王怀忠）（ＲｅｃｅｉｖｅｄＪｕ...     

A STUDY OF THE ELASTO－PLASTIC AXIALLY TENSILE PROPERTIES OF METAL MATRIX COMPOSITES WITH FIBER－END DEBONDING

ＡＳＴＵＤＹＯＦＴＨＥＥＬＡＳＴＯ－ＰＬＡＳＴＩＣＡＸＩＡＬＬＹＴＥＮＳＩＬＥＰＲＯＰＥＲＴＩＥＳＯＦＭＥＴＡＬＭＡＴＲＩＸＣＯＭＰＯＳＩＴＥＳＷＩＴＨＦＩＢＥＲ－ＥＮＤＤＥＢＯＮＤＩＮＧＳｕＸｉａｏｆｅｎｇ（苏晓风）ＣｈｅｎＨａｏｒａｎ（陈浩然）（...     

3-D numerical study on the bending of symmetric composite laminates

３－ＤＮＵＭＥＲＩＣＡＬＳＴＵＤＹＯＮＴＨＥＢＥＮＤＩＮＧＯＦＳＹＭＭＥＴＲＩＣＣＯＭＰＯＳＩＴＥＬＡＭＩＮＡＴＥＳＣｈｉｅｎＷｅｉ－ｚａｎｇ（钱伟长）;ＨｕａｎｇＱｉａｎ（黄默）;ＦｅｎｇＷｅｉ（冯伟）（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｔｙｏｆＴｅｃ...     

THE APPLICATION OF MULTI－SCALE PERTURBATION METHOD TO THE STABILITY ANALYSIS OF PLANE COUETTE FLOW

ＴＨＥＡＰＰＬＩＣＡＴＩＯＮＯＦＭＵＬＴＩ－ＳＣＡＬＥＰＥＲＴＵＲＢＡＴＩＯＮＭＥＴＨＯＤＴＯＴＨＥＳＴＡＢＩＬＩＴＹＡＮＡＬＹＳＩＳＯＦＰＬＡＮＥＣＯＵＥＴＴＥＦＬＯＷＺｈｏｕＺｈｅ－ｗｅｉ（周哲玮）（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｉｌｙ;Ｓｈａｇ...     

Generalized variational principles of symmetrical elasticity problem of large deformations

ＧＥＮＥＲＡＬＩＺＥＤＶＡＲＩＡＴＩＯＮＡＬＰＲＩＮＣＩＰＬＥＳＯＦＳＹＭＭＥＴＲＩＣＡＬＥＬＡＳＴＩＣＩＴＹＰＲＯＢＬＥＭＯＦＬＡＲＧＥＤＥＦＯＲＭＡＴＩＯＮＳＺｈａｏＹｕ－ｘｉａｎｇ（赵玉祥）ＧｕＸｉａｎｇ－ｚｈｅｎ（顾祥珍）ＬｉＨｕａｎ－ｑｉｕ...     

TWO－DIMENSIONAL DEFORMATION OF ANANISOTROPIC ELASTIC BODY WITH A PARABOLIC BOUNDARY

ＴＷＯ－ＤＩＭＥＮＳＩＯＮＡＬＤＥＦＯＲＭＡＴＩＯＮＯＦＡＮＡＮＩＳＯＴＲＯＰＩＣＥＬＡＳＴＩＣＢＯＤＹＷＩＴＨＡＰＡＲＡＢＯＬＩＣＢＯＵＮＤＡＲＹＨｕＹｕａｎ－ｔａｉ（胡元太）ＺｈａｏＸｉｎｇ－ｈｕａ（赵兴华）（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｉｔｙ...     

EQUILIBRIUM IN ABSTRACT ECONOMICS WITH A NON－COMPACT INFINITE DIMENSIONAL STRATEGY SPACE

ＥＱＵＩＬＩＢＲＩＵＭＩＮＡＢＳＴＲＡＣＴＥＣＯＮＯＭＩＣＳＷＩＴＨＡＮＯＮ－ＣＯＭＰＡＣＴＩＮＦＩＮＩＴＥＤＩＭＥＮＳＩＯＮＡＬＳＴＲＡＴＥＧＹＳＰＡＣＥＤｉｎｇＸｉｅ－ｐｉｎｇ（丁协平）（ＳｉｃｈｕａｎＮｏｒｒｎａｌＵｎｉｖｅｒｓｉｔｙ,Ｃｈｅｎ...     

PSEUDOSPECTRAL－FINITE DIFFERENCE METHOD FOR THREE－DIMENSIONAL VORTICITY EQUATION WITH UNILATERALLY PERIODIC BOUNDARY CONDITION

ＰＳＥＵＤＯＳＰＥＣＴＲＡＬ－ＦＩＮＩＴＥＤＩＦＦＥＲＥＮＣＥＭＥＴＨＯＤＦＯＲＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＶＯＲＴＩＣＩＴＹＥＱＵＡＴＩＯＮＷＩＴＨＵＮＩＬＡＴＥＲＡＬＬＹＰＥＲＩＯＤＩＣＢＯＵＮＤＡＲＹＣＯＮＤＩＴＩＯＮＸｉｏｎｇＹｕｅ－ｓ...     

非完整系统稳定性的若干进展

介绍非完整系统稳定性理论的某些近代进展,包括非完整系统平衡位置关于全部变量的稳定性,平衡状态流形的稳定性,平衡位置关于部分变量稳定性及其与关于全部变量的稳定性的关系,平稳运动的稳定性,以及非完整控制系统的镇定．同时,讨论非完整系统稳定性的几个主要应用,并给出几个未来研究方向的建议      

切塔耶夫型非完整系统的广义梯度表示

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.     

强迫谐振动下连续体结构拓扑优化

应用结构拓扑优化ICM(独立连续映射)方法,对强迫谐振动下结构拓扑优化问题建立了以重量极小为目标,位移幅值为约束的优化模型.位移幅值采用一阶泰勒展式近似,由于拓扑优化中设计变量数目通常很多,对强迫谐振动位移幅值的敏度分析推导了伴随法公式,使得一次敏度分析可以计算出对所有设计变量的偏导数,克服了采用直接法敏度分析中一次只能计算出对一个设计变量的偏导数的不足.算例表明用伴随法分析敏度在结构拓扑优化中可以大幅提高计算效率,ICM方法采用独立于截面及形状参数的拓扑优化设计变量更清晰地反映了拓扑优化的本质.     

LAGRANGE'S THEOREM FOR A CLASS OF NONHOLONOMICSYSTEMS AND ITS APPLICATION

I.IntroductionSinceE.T.Whittaker.proposedfoestabilit}'problellll'lofnonholononlicsystemsin1904forthefirsttime,thescholarsathomeandabroad11a\'emadealotofresearchesontheequilibriunlstabilityoflinearand11olllinearnonllolollolnicsystems,andhaveobtainedaseriesofimportantresultslZ--7].Hobbled'er,theexpositionandapplicationrelatedtoLagrange'stheorenlinthestabilityanalysisfornonholonomicsystemsisseldonlseenuptonow.Althoughitwasmentionedinreference[3].aspecialdiscussionhasnotbeencarriedoutyet.Asafam…     

Energy integrals for mechanical systems with nonlinear nonholonomic constraints

The work analyzes energy relations for nonholonomic systems, whose motion is restricted by nonlinear nonholonomic constraints. For the mechanical systems with linear constraints, the analysis of energy relations was carried out in [1], [2], [3], [4], [5], [6] …. On the basis of corresponding Lagrange’s equations, a general law of the change in energy dε/dt is formulated for mentioned systems by the help of which it is shown that there are two types of the laws of conservation of energy, depending on the structure of elementary work of the forces of constraint reactions. Also, the condition for existing the second type of the law of conservation of energy is formulated in the form of the system of partial differential equations. The obtained results are illustrated by a model of nonholonomic mechanical system.     

Differential-algebraic equations of programmed motions of Lagrangian dynamical systems

We suggest a method for constructing the dynamic equations of manipulator systems in canonical variables. The system of differential dynamic equations has an integral manifold corresponding to the holonomic and nonholonomic constraint equations. The controls are determined so as to ensure the stability of this manifold. We state conditions for the exponential stability of the manifold and for constraint stabilization when solving the dynamic equations numerically by a simplest difference method. We also present the solution of the problem of control of a plane two-link manipulator.     

New methods to find solutions and analyze stability of equilibrium of nonholonomic mechanical systems

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.     

Optimal control of stretching process of flexible solar arrays on spacecraft based on a hybrid optimization strategy

The optimal control of multibody spacecraft during the stretching process of solar arrays is investigated,and a hybrid optimization strategy based on Gauss pseudospectral method(GPM) and direct shooting method(DSM) is presented. First, the elastic deformation of flexible solar arrays was described approximately by the assumed mode method, and a dynamic model was established by the second Lagrangian equation. Then, the nonholonomic motion planning problem is transformed into a nonlinear programming problem by using GPM. By giving fewer LG points, initial values of the state variables and control variables were obtained. A serial optimization framework was adopted to obtain the approximate optimal solution from a feasible solution. Finally, the control variables were discretized at LG points, and the precise optimal control inputs were obtained by DSM. The optimal trajectory of the system can be obtained through numerical integration. Through numerical simulation, the stretching process of solar arrays is stable with no detours, and the control inputs match the various constraints of actual conditions.The results indicate that the method is effective with good robustness.     

Special Mei symmetry and approximate conserved quantity of Appell equations for a weakly nonholonomic system

The weakly nonholonomic system is a nonholonomic system whose constraint equations contain a small parameter. The special Mei symmetry and approximate conserved quantity of Appell equations for a weakly nonholonomic system are studied. Appell equations for a weakly nonholonomic system are established and the definition and the criterion of the special Mei symmetry of the system are given. The structure equation of the special Mei symmetry for a weakly nonholonomic system and approximate conserved quantity deduced from the special Mei symmetry of the system are obtained. Finally, special approximate conserved quantity issues of Appell equations for a two freedom degrees weakly nonholonomic system are investigated using the results of this paper.     

动态规划求解空间双臂机器人非完整运动最优控制问题

通过自适应动态规划研究自由漂浮空间双臂机器人运动的最优控制问题．针对空间双臂机器人的非完整性运动,采用自适应动态规划(Adaptive Dynamic Programming, ADP)方法求解其最优控制问题．根据多体动力学理论,推导了载体位置、姿态均无控制条件下,双臂空间机器人满足的系统动量守恒关系的非完整约束方程,并将其转化为控制系统的状态方程,从而将双臂空间机器人的非完整运动规划问题转化为对非线性系统的控制问题．文中根据自适应动态规划网络结构,利用神经网络来近似性能指标函数,进而用龙格库塔法求解状态变量．并给出了适合该类问题的一种效用函数具体表达式,保证了空间双臂机器人到达期望位置后不再继续运动．实现了对空间双臂机器人非完整运动规划的最优控制．数值仿真实验验证了ADP对求解空间双臂机器人非完整运动规划最优控制问题的有效性．