查询词典 finite difference approximation

According to practical work condition, section of a three segment hoist boom is self-determined with SECWRITE commands, then a finite element model is directly established in ANSYS environment with ANSYS finite element analysis software. Using Beam44 beam unit and node degree of freedom coupling technique to simulate connecting between each boom section and conduct finite element analysis, calculated result of stress deformation for the boom is obtained. The result from digital simulation is in relative coincidence with theoretical analytic result and the nonlinear decline occurrence in boom bending moment curve is explained.

以ANSYS有限元分析软件为工具，按吊臂实际工况，运用SECWRITE命令自定义三节吊臂截面直接在ANSYS环境下创建有限元模型，使用Beam44梁单元和节点自由度耦合技术模拟各节臂的连接，进行有限元分析，得到吊臂应力变形数值计算结果，数值模拟所得结果与理论解析解相吻合，解释吊臂弯矩图出现非线性下降的原因。

The main contents are as follows: Creating finite element model of cradle carriage, top carriage and trail of the howitzer. The structural static stress analysis of are dealt with finite element program system I-DEAS. For accuracy and computation cost, the nonlinear finite element structural dynamics model of the howitzer is created with different elements such as solid elements, shell elements and beam elements.

主要包括以下几个方面工作：建立了该炮摇架、上架和下架的三维有限元静力学模型，并应用I－DEAS有限元软件进行了强度分析；顾及计算准确性和计算成本，应用实体单元、壳单元和梁单元相结合的方法建立了该炮的非线性有限元结构动力学模型。

This paper makes a three-dimensional model for QCM and analyzes directly the coupled phenomenon of the structural and electric fields of QCM with finite element analysis software ANSYS10.0. Through analyzing the convergence of the resonant frequency of QCM, the correctness of the finite element analysis is proved. The influence of different sizes of electrode on vibration of QCM and an optimal size of electrode is discovered, namely thickness of 100 nm and radius of 3 mm. The design of mesa on crystal plate is provided to solve the problem that the energy trapping is not good enough. This design proves valid based on finite element calculation and an optimal size of the mesa is given, namely height of 9.8 μm.

基于有限元分析软件ANSYS10.0对石英晶体微天平进行三维建模，验证了建模的正确性，并对不同电极结构尺寸进行仿真计算，对出现的耦合情况进行了分析，通过实验结果对比，提出较佳电极尺寸结构为厚度100 nm，半径3 mm；为解决金电极能陷效应不够理想的问题，提出在晶片上下表面筑平台的设计，有限元计算结果表明此设计能改善电极区的能陷效应，并且较佳平台高度为9.8μm。

With a 586 computer and ALGOR FEAS software of finite element method, the static stresses of the equalizing bar are obtained by finite element analysis for three finite element models of beam, plate and brick element.

在微机586和ALGOR FEAS有限元软件环境下，对推土机平衡梁以梁、板、块单元为主分别建立了三种有限元模型和进行了有限元应力分析。

The paper gives stiffness matrix and mass matrix in finite element analysis of the ground vibration problem caused by track traffic by using three-dimension finite element method. Because three-dimension finite element analysis is very difficult, it is transmitted into a quadratic programming, which can be calculated by neural network.

本文融合神经网络技术和遗传算法，对轨道交通引起的地面振动进行了正分析和反演，并利用计算机技术实现了地面振动的三维动画模拟，这主要包括：(1)研究了压缩映射遗传算法，利用Banach空间的不动点定理证明了压缩映射遗传算法可以收敛到全局最优值，弥补了标准遗传算法不能收敛至全局最优值的不足。

It is found by solving the self-consistency equa tion that, at zero chemical potential and finite temperature the chiral phase transition is of second order, while both at finite temperature and density and at zero temperature finite density this transition is of first order.

通过求解序参量所满足的自洽方程，其结果表明：在零化学势有限温度情况下，有二级手征相变发生；对于有限温度和密度以及零温有限密度两种情况，手征相变为一级，并且其转变温度或密度与费米子所处的初始相有关，即从破缺相到正常相的转变温度或密度不同于从正常相到破缺相的转变温度或密度。

This paper is based on the former research taking the No.1 Tong-Lv Bridge as an example; the large universal finite element program Midas/Civil is adopted, a three-dimensional finite element model is established. The static performance, the comparative analysis of influence surfaces, the experimental study and the analysis of a local finite element model of the new style three-span continuous through type bow-string arch bridge is made. With these studies, this paper is aimed at revealing the performance of this kind of construction.

本文在前人研究的基础上，以通吕一号桥为背景，采用空间有限元法对结构形式新颖的三跨连续下承式系杆拱桥的静力性能、影响面比较分析、实桥荷载试验、局部节点分析等进行研究，旨在深入理解该结构形式桥梁的力学性能，为今后相同结构体系桥梁的结构分析提供可以参考的建议。

A finite element analysis on the new method is presented in this paper. Based on the finite element analysis, tension tests of 18 steel bars in different diameters and holes are carried out. The results of tests, which are according with that of finite element analysis, validate the new method to determine real stresses of steel bars by drilling/enlarging small holes. Furthermore, some suggestions in using of the new method are given.

本文针对该新方法进行了有限元分析，并在此基础上进行了18种不同钢筋直径和不同孔径的带孔短钢筋拉伸试验，试验结果与相应有限元计算结果一致，验证了钻／扩孔确定钢筋实际应力的新方法，并提出了若干工程适用建议。

In the finite element analysis, by adding individual beam elements to model the connector between top joints and chords in finite element model, based on the experimental model, the factors affecting the shape forming process of dome, such as the bending stiffness of duckbilled connector and the size of top joints, can be taken into account; A whole and continuous analysis method is put forward for solving the question of applying the member forces produced in the shape forming process to the finite element models of load analysis.

有限元分析中，采用节点增设独立梁单元的方法，研究了鸭嘴半刚性连接和上弦节点域大小对穹顶成形过程的影响；提出了统一连续的分析方法，很好的解决了成形初应力向穹顶承载力有限元分析模型中的施加问题。

There are three difference formats in this thesis. They are backward difference, Crank-Nicolson"s difference and Galerkin"s difference.

本文对时间域采用的离散格式有两点向后差分、Crank-Nicolson格式差分和Galerkin差分等。

The studies on the developing of new media are very important to the increasing of the area density of HDD and to the implementation of hybrid recoding technology.

光磁混合记录方法，是一种可以突破超顺磁极限的限制，并进一步提高硬盘记录密度和读写速率的一种新型超高密度信息存储方式。

In io, mTOR inhibition promotes T cell anergy under conditions that would normally induce priming.

体内研究中，在正常可激发免疫反应的条件下，抑制mTOR可促使T细胞无能。