有限元法

The result shows that Ritz finite element method is suitable for deep excavation dewatering calculation, and Galerkin finite element method maybe put into practice after well system is simplified.

比较分析结果可知，本文运用的里茨有限元法适用于深基坑降水计算，而运用迦辽金有限元法需对井点进行处理，才能用于实际计算。

In the basic theory, the basic STFEM theory is perfected, the variation principle in form of a convolution included is given and proved.

在时空有限元法的基础理论方面，完善了时空有限元法的基础理论，给出并证明了具有普适意义的含卷积运算的变分定理。

But the rigid body limit equilibrium method can not reflect the process of progressive instability and mechanical mechanism on failure for rock mass while the nonlinear finite element method is difficult to solve the displacement discontinuity of weak structural plane.

重力坝的深层抗滑稳定分析多采用刚体极限平衡分析方法和非线性有限元法，但通常的刚体极限平衡法不能反映坝基岩体渐近失稳过程和破坏的力学机制，非线性有限元法则难以解决坝基中软弱结构面位移不连续问题。

The weak formulation permit is satisfied not point by point, finite element method balances only at node neighborhood, in unit balance is not required, in analytical method single check from infinite series does not satisfy the equation, but infinite number of points satisfy the equation, and then the weak formulation of dual system of Hamilton equations was educed.

基于基本方程和边界条件的弱形式，给出相应的广义变分和不同形式的有限元所采用的弱条件，说明弱形式允许不是逐点满足，有限元法只在节点邻域平衡，在单元内不要求平衡，解析法用无穷级数中单取一项也不满足方程，也是无穷多项在积分下满足，进而导出对偶体系弱形式哈密尔顿方程。

Incurrent research, aiming at the rupture problem engendered in the shooting process of acertain 5.56mm automatic rifle, the strain and stress distributions on the cartridge caseunder the action of axial pull have been analyzed. Based on the theories of elastic-plasticmechanics and contact mechanics, a mathematic and physical model of the cartridge-caseand chamber system has been set up; and based on the platform of the general softwarepackage APDL of ANSYS for finite element analysis, a parameterized model of thecartridge-case and chamber system has also been established. The method for nonlinearFEA has been adopted to analyze the stress distribution on the entire cartridge-case andchamber system, and the method of contact element has been employed to investigate thecontact stress between the cartridge case and chamber, and then the influences of frictioncoefficient and locking space on the static and dynamic stress and strain response of thecartridge case and chamber to the action of power gas have also been discussed. On thebasis of a lot of numerical tests, a kind of element Plane13, which is concentrated incoupled computation of heat and construction, has been used finally to simulate thetransient response of the cartridge-case and chamber system to the power gas. Throughloading the temporary thermal characteristics of explosive gas in the procedure of emulate, the corresponding transient thermal stress distributed on the entire system under thecombined load of transient thermal stress and transient pressure has been obtained. Owingto these comprehensive considerations, the numerical results obtained in this paperrepresent the actual situations comparatively exactly.

本文针对某5.56mm自动步枪在工作中出现断壳的问题，分析了弹壳在轴向拉力作用下的应力应变；基于弹塑性力学及接触理论，建立了弹壳弹膛系统的数学、物理学模型，在通用有限元ANSYS软件的参数化建模工具APDL平台上，建立了弹壳弹膛系统的参数化模型；采用非线性有限元法计算了弹壳弹膛系统的整体应力，引入接触单元法分析弹壳和弹膛的接触压力，探讨了在不同的摩擦系数和不同的闭锁间隙对弹壳弹膛静、动态响应的影响；本文进行了大量的尝试，最后确定采用热、结构耦合单元Plane13，在计算中加载了火药气体的温度历程，成功的获得了弹壳弹膛系统在瞬态的热载荷和瞬态的压力载荷同时作用下弹壳弹膛系统的热应力数值解，考虑因素全面，比较真实的反映了弹壳弹膛系统在火药气体压力和热载荷下作用的情况。

To assure astringency, sometechnologies have been used such as iterative penality function methods,assemblage mass matrix, reduced integration algoritlun, NeWton iteration methodwith parameters for non-linear equation set, introducing relax factors and doublesteps solution and so on, and an algorithIn for solving the nonlinear equation set offlow field by FEM has been presented.

基于有限元法建立了流场求解列式，为保证其收敛性，采用了迭代罚函数法，集中质量矩阵，缩减积分计算，带参数的Newton迭代求解，引入松驰因子及双层解法等技术，提出了一套适合流场有限元方程计算的非线性方程求解方法。

At first, the method used the finite element method to design the combination plan of submains and hollow forgings capable of meeting with the requirement of the douches in a micro-irrigation system that the water flux and water-discharging uniformity of the douches be equilibrated, and the pressure heads of the correspondent submain units; next, the parameters of the design and the pressure heads were input into the dynamic programming model and then the optimal combination design of the diameters of various orders of micro-irrigation pipes in the system as well as the pressure heads necessary to operate the system was obtained.

提出了一种基于有限元法和动态规划法的微灌系统管网优化设计方法，该方法先利用有限元法，设计出符合灌水器平均流量和灌水均匀度要求的支管与毛管参数组合方案，及相应的支管单元操作压力水头，然后将这些参数组合与支管单元操作压力水头代入动态规划模型，即可设计出微灌系统各级管道管径的最优组合方案，并确定微灌系统所需的操作压力水头。

The proposed method directly gets deflection and moment of beam structures at the same time, and overcomes the shortcoming of low accuracy in beam moment calculation of displacement FEM.

BSWI混合有限元法可同时直接求解梁结构的挠度和弯矩，克服了位移有限元法弯矩求解精度不高的缺点。

This article focuses on research of prediction of rock-burst happened in Cangling extreme long-tunnel engineering, comparison of tunnel carving details in the performing stage and prevention measures.

通过对苍岭特长隧道岩爆问题的预测研究和施工阶段洞身开挖情况对比，以及针对本工程的岩爆防治措施研究，探讨了岩爆预测判据对苍岭隧道工程的适用性，揭示了苍岭隧道围岩的岩性特征和初始应力场，掌握了苍岭隧道岩爆发生的烈度和基本分布规律，提出了对岩爆问题的工程防治措施，另外，根据工程区地质条件和岩石物理力学性能参数，建立了相应的地质力学模型，采用有限元法建模反演分析，其结果与通过钻孔水压致裂试验测得的地应力结果比较，显得较为吻合，并得到施工阶段通过洞壁应力恢复法分析结果的验证，验证表明理论模型和有限元模型的适用性及分析应力场是较为准确和合理的，并在此基础上对苍岭隧道岩爆进行分段预测和采取了较有成效的工程防治措施，具有较高的工程应用价值。

Finite element method is based on the actual ship models, a true reflection of the real ship distribution of the specific structure. This paper also uses empirical formula to calculate the inherent frequency of the catamaran; contrast them in the process of modeling the structural stiffness, and quality of the different treatments, as well as natural frequency calculated from the results of differences analyze the different and the reason between the finite method and the empirical formula method which used to calculate the inherent frequency of catamarans in the vibration analysis.

有限元方法是根据实际船型，较真实的反映了实船结构的具体分布特征；本文还采用经验公式对该船的固有频率进行了计算，对比它们在建模过程中对结构刚度、质量的不同处理，以及计算所得固有频率结果的差异，分析了在双体船振动特性分析中有限元法与经验公式法的结果略有差距及其原因。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。