查询词典 finit element method

The examples given have proved the advantage of the Boundary Element Method. In the analysis of the fracture mechanics using Boundary Element Method, the calculation model of one-quarter singular element has been established, and has been proved its validity.

把边界元法应用于线弹性结构断裂分析中，建立了裂尖奇异区分析的四分之一奇异元计算模型，算例表明，用四分之一奇异元分析断裂力学问题是一种有效的逼近裂尖场的数值方法。

Compared with the existing finite element eigenanalysis method[8]for asymptotic fields near the crack tip, current method has the following several characteristics: The jump-off that educes the virtue work formula is different; when solving the characteristic formula with FEM, the form of the element is non-confirming element; the singular transformation technique is not used in the assumption of displacement fields surrounding the wedge tip.

该方法与过去的有限元特征分析方法[8]相比的显著特点是：导出虚功原理的出发点不同；有限元单元形式为非协调元；楔形体端部邻域内的位移场假定没有采用奇异变换技术。

This paper, which focused on the structure optimization theory and method, has finished such studies as follows: The three dimension model has been built, which provide the necessary conditions for the building of the dynamics equivalent model. By the launch dynamics simulation, the loads of the key joints when the rocket is launched has been got, which provide the necessary data for the finite element analysis and the structure optimization. The finite element model of the excess weight parts of the rocket has been built, buy the finite element intension analysis of the model in two conditions, the displacement and the stress of the key points have been got, which make us know the distributing of the stress and the transmogrification of the part. To satisfy the intension and the precision design request and to decrease the weight of the part as many as possible, the part has been topology optimized by the structure optimization theory and method. After that, the new model has been analysis in structure and launch dynamics. The contrast of the character change of the old part and the new part and the influence on the rocket system have been studied.

本文以结构优化理论和方法为核心，主要做了以下工作：建立了某自行火箭炮全炮三维实体模型，为建立该火箭炮系统的动力学等效模型提供了必要条件，进行了发射动力学仿真，得到该火箭炮发射装置各关键连接部位在发射状态下的载荷，为有限元分析和结构优化提供了必需的数据；建立了该火箭炮发射装置超重部分的有限元模型，分两种工况，对模型进行了有限元强度分析，得出了关键部位的位移和应力值，对其的应力和变形分布有了具体的了解；运用结构优化的理论和方法，对该火箭炮发射装置超重部分进行了拓扑优化，使其在满足强度和精度的要求下尽可能多地减轻重量，对优化后得到的模型进行了结构分析和发射动力学分析，对比了该部件优化前后的特性变化以及对火箭炮系统的影响。

In this paper, the improvement of the low velocity impact resistance performance of composite plates using shape memory effect of shape memory alloy is analyzed by using finite element method, The constitutive relationship and the model of finite element analysis of SMA hybrid composite plates are established, The finite element equation is solved by using the Newmark direct integration method and the modified Hertzian contact law.

应用有限元方法分析了利用形状记忆合金的记忆特性提高复合材料抵抗低速冲击的能力，建立了SMA复合材料板的本构关系和有限元分析模型，利用修正的Hertzian接触定律确定冲击接触力，应用Newmark直接积分法求解方程；研究结果表明利用SMA的形状记忆功能可有效地改善复合材料板的低速冲击响应性能。

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。

Compared with the research of the geometric nonlinear finite element method home and aboard in the components such as bar, plate, beam and shell element, the present problems is analyzed and the future research direction is described for the theoretical research and program design of geometric nonlinear finite element method.

综合比较了几何非线性有限元法在杆、梁、板、壳等方面的国内外研究成果，指出目前仍存在的问题，提出今后的发展方向，为几何非线性有限元的理论研究与程序设计提供参考。

For some shortcomings of unknown quantity numbers in finite element method, QR-method establishes a transformed relationship between a unit node displacement vector and the entire framework of spline node displacement vector,making the structure of the total stiffness matrix, damping matrix, mass matrix directly superimposed in no need of finite element method in the first expansion after the superposition process. So the method greatly simplifies the calculation process and improves computing speed.

针对有限单元法中未知量数目很多的缺点，QR法建立起单元结点位移向量与整个框架样条结点位移向量的转化关系，使得结构总刚度矩阵、阻尼矩阵、质量矩阵可以直接叠加，不需要有限单元法中先扩张后叠加的手续，大大简化了计算过程，提高计算速度。

And their improved methods were also researched, for example the force density method with the triangle element transformed the three links, surface stress density method, surface stress density method of sub-structure and nonlinear finite element method of little youngs modulus.

并且对它们的改进方法，比如三角形单元转化成三杆单元的力密度法、面力密度法、考虑子结构的面力密度法和小杨氏模量的非线性有限元法进行了深入的探讨。

At present the numerical simulation of electromagnetic method of finite difference method, finite element method, boundary element law, integral equation method, and so on were commonly used in the exploration.

目前电磁法勘探中常用的数值模拟方法主要有：有限差分法、有限单元法、边界单元法和积分方程法等。

Three moment method,the transition matrix method and finite element method in shipping shaft system alignment are used ,the application of finite element method in shipping shaft system alignment is proved to be more reasonable through an example .

并以某实船为例，利用三弯距法、迁移矩阵法和有限元法对船舶轴系进行校中计算，说明有限元法更先进合理。

Effective local search tactics reaches local searchers when they are ready to buy - with every way that it is possible for them to buy from you.

有效的地方搜索策略达到当地的搜索，当他们准备购买-以各种方式，这是他们有可能从您那里进行购买。

The first two are periodic sentences for their beginnings; and the fifth and the last are also periodic sentences each for the embedding of a parenthetic structure.

1960年代中后期，当战后女权主义和当时的许多其他抗议运动在西欧和北美发展成某种势力时，性别的概念演绎成补充和延伸生物性别差异的概念。