变分法

Lastly we made a comparison between variational method and finite element method on the lateral loaded behaviour of barrette pile group, and also proved variational method is a feasible and efficiency method.

论文在最后一章采用有限单元法和变分法对壁板桩水平承载特性进行了对比验证，证实了应用变分法分析壁板桩承载特性是一种可行和有效的研究方法。

In modern physics research, the calculus of variations has a broad application of law. As a solid mechanics, structural mechanics and computational mechanics of the theoretical foundation, it has important value in theory and practice on the mechanics; Variation method ruled out the perturbation of the restrictions can be widely used in many state-level and the state function in the calculation in the optical; Calculus of variations can be calculated with the parameters, we can guarantee the reliability of the results, can effectively reduce the workload of calculation, It can be said that the applications of calculus of variations are very broad.

在现代的物理学研究中，变分法有着广泛的应用：在力学上，变分法作为固体力学、结构力学及计算力学的理论基础，在理论上和实践上都有重要的价值；在光学上，变分法排除了微扰法的限制，可以广泛应用于诸多定态能级和态函数的计算中；在量子力学的应用中，具有可算出系统的参数，既可以保证计算结果的可靠性，又能有效地减少计算的工作量等的优点，可以说变分法的应用领域十分广阔。

From the perspective of the variational discussion of Lagrange\'s contributions to the principles and analyzation of mechanics,the interaction between the calculus of variations and mechanics,especially the variational principles is made clear.

结合拉格朗日微积分代数化方案和18世纪可积性条件的研究，探讨了拉格朗日关于变分法基础研究的数学背景及相关工作；通过对《分析力学》中静力学约束平衡问题的细致考察，系统探讨了变分法中乘子法则的力学渊源、提出过程及意义。

The numercial simulation has been carried out, and the experimental results show that this method has been improved significantly comparing with the traditional one in nonlinear optics. Secondly, a second order system of semilinear elliptic equations, which comes from a mathematics model of the electric potential distribution of a media surrounded with the protein, is transformed into a variational problem, the existence of solution of it is proved by using variational principle and Trudinger—Moser inequality, and the relation between the solutions of variational problem and the solutions of its dual problem is obtained.

首先，讨论了非线性光学中的二次谐波产生的耦合方程组，利用变分法证明了耦合方程组非平凡解的存在性，然后进行了数值模拟，实验结果表明文中方法比经典的非线性光学中的方法有较大的改进，这对优化光倍频器件的设计将有所帮助；其次，将一类二阶半线性椭圆型方程组转化为一个变分问题，然后利用变分法和

The variational problems of the complete functional in calculus of variations are studied deperding on the arbitrary arguments,arbitrary multivariable functions and arbitrary-order partial derivatives of multivariable functions.

研究变分法中依赖于任意个自变量、任意个多元函数和任意阶多元函数偏导数的完全泛函的变分问题；提出并证明了完全泛函的变分问题的定理，采用偏微分算子，给出了完全欧拉方程组。

This method is variational method, which will be much faster and more efficiency than other method.Firstly we use gauss integral method to disperse the least potential energy of barrette pile group, with the help of vertical settlement finite series and Mindlins equation, we derived vertical load-settlement solution of barrette pile group.

另外，目前有关壁板桩群桩水平承载特性的研究也比较少，因此，为了加深对壁板桩群桩承载特性的理解，本文利用变分法对壁板桩群桩竖直或水平受荷情况下的承载特性进行了初步的研究，通过变分法直接得出荷载位移显式方程，较之以往方法更加快捷。

In order to reasonably depict four basic problems with friction, one Coulomb friction new form in first Kirchhoff stress is proposed to deal with finite deformation problems, other Coulomb friction form in incremental mode to elastoplastic flow theory; Hilbert function spaces concerning elastoplastical problems with friction are established, so it makes all operations and calculations in the treatise standardized within the scope of reasonably topologic structure; In view of functional extremum, the equivalence between generalized variational inequalities principles in elastoplasticity with friction and corresponding basic problems are testified by inducing Lagrangian multipliers, so it provides a rationally theoretical basis for numerical methods in elastoplasticity with friction; From the viewpoint of variational inequality, the theory of generalized variational inequalities in elasticity and elastoplasticity with frictional constraint is studied, and the uniqueness and existence of the solution of FEM is proofed under the proposed conditions of stress compatibility, and them FEM approximation and a discrete solution are discussed; Based on the principles of generalized variational inequalities in elastoplasticity with friction, direct generalized variational inequalities methods is pretended, which is a natural generalization and development of direct variational methods; Using generalized variational inequalities methods, some examples in metal forming including plane deformation, upset and extrusion are analyzed and the results prove that all the theories and methods in the paper are right, feasible, accurate and advanced.

主要内容有：为了合理地描述金属塑性成形中摩擦约束弹性、弹塑性基本问题，提出和研究了有限变形下以Kirchhoff第一应力表示的Coulomb摩擦定律形式和弹塑性流动理论下以增量形式表示的Coulomb摩擦定律表示形式；系统建立了摩擦约束弹塑性问题的Hilbert函数空间，使本文规范在一个具有合理的代数拓扑结构内进行一切操作和运算；利用Lagrange乘子，从泛函极值的角度系统地阐述和论证了一系列摩擦约束弹性、弹塑性广义变分不等原理与相应的实际问题之间的等价性，它为处理摩擦约束的弹塑性力学数值方法提供了合理的理论基础；从变分不等式的角度出发，阐述了对应于摩擦约束弹性、弹塑性问题的广义变分不等式理论，首次提出了在应力相容性条件下，它的有限元解具有存在唯一性，进而讨论了其有限元近似及离散解法；基于摩擦约束弹塑性广义变分不等式原理，首次提出了直接广义变分不等式方法，这一方法是直接变分法的合理推广和发展；利用直接广义变分不等式方法对金属压力加工中的平面变形问题、镦粗、挤压等塑性成形问题进行了分析计算，验证了该理论和数值算法的正确性、实用性、精确性和优越性。

By investigating Newton\'s Problem of the Solid of Least Resistance,John Bernoulli\'s Brachystochrone Problem and Jacob Bernoulli\'s Isoperimetric Problem, the physics and Calculus background of the calculus of variations is illustrated,the fundamental thought together with the patterns of solutions are summarized,and the ideas and the interaction of the pioneers,such as the Bernoullis and B.

通过考察牛顿最小阻力体问题、约翰·伯努利最速降线问题和雅可布·伯努利等周问题等问题的提出过程及解决方法，深入探究了变分法诞生的深刻背景，提炼和概括出了伯努利兄弟和泰勒等先驱者解决变分问题的基本思想和求解模式，追溯了其微积分渊源，并分析了三位先驱(来源：ABCbc论文64网www.abclunwen.com)者之间的变分法思想传承及相互影响。3。

By investigating Euler\'s application of variational mathematics to mechanics, especially his principle of least action,the mechanics background of his research and its influence on Lagrange are revealed.6.By the discussion of Lagrange\'s innovation and generalization of the calculus of variations,the reason why Lagrange puts forward his method of variation by comparing Euler\'s method is explained.

深入细致地分析了拉格朗日对变(来源：ABC论文2d网www.abclunwen.com)分法所做的变革和发展：(1)通过比较欧拉方法和拉格朗日方法，探讨了拉格朗日变分方法——δ-方法提出的动因；(2)详细论述了拉格朗日早期对变分法发展所作的重要贡献；(3)探究了拉格朗日δ-方法由非参数形式向参数形式转变的原因。7。

In this paper we separate the Hamiltonian into three parts: a spherical symmetry Hamiltonian; a z-component of the angular momentum operator, and a non-spherical symmetric potential as the perturbation operator, and provide a propose method by separating the potential containing squared magnetic field B^2 into two parts spherical symmetric and non-spherical symmetric ones so that the first-order energy correction due to the non-spherical symmetric potential is zero, and the second-order correction due to B^2 can be obtained by a simple variational method.

采用变分法和微扰法相结合的方法，把高强度磁场中氢原子的哈密顿H分为三部分：球对称哈密顿；z分量角动量算符相应部分和非球对称势微扰，并用一种特别规定的分解法将哈密顿H中含磁场平方项的势能分解为球对称与非球对称两部分，且使非球对称部分引起的一级修正能量值为零，并采用一种简便的变分法直接求出B^2对能级的二级修正值。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。