查询词典 finite element method

In the cylindrical coordinates, the related basic formula and solve method of the equivalent boundary element method were established and derived, and a new contact element was introduced to model the hybrid of structure and soil.

同时建立并推导了在柱体坐标系下插入式大圆柱壳墩式结构的等效边界元数值分析的相关基本方程和求解方法，并提出了一种新的接触面单元以模拟结构和土体间不同材料的耦合关系。

According to the studied results at present, the studied objects are mainly thin plate and beam about sound radiation mode, a method computed sound radiation mode of complex structure is presented in this dissertation, according to the results of the previous two chapter, a theoretical method to solve acoustical radiation mode and acoustical radiation efficiency of complex structure by boundary element method and acoustical radiation theory is posed, the acoustical radiation power is expressed as a Hermitian quadratic form, while the radiation modes is determined by general eigenvalue decomposing, and then the radiation efficiency is computed via the orthodoxy of radiation modes with regard to impedance matrix and average velocity matrix; lastly, the validity of the method is proved by pulsating sphere and radiating cube with analytical results. According to results of the form three chapter, the structure sound radiation sensitivity is studied in detail, the sound radiation power of structure can be expressed as positive Hermitian quadratic form, the sound radiation sensitivity can be expressed as two parts by partial differential with respect to design variable, which are sensitivity of boundary velocity and impedance matrix, combined with the theory of FEM and BEM, the structure sound radiation can be translated to the analysis of structure dynamic sensitivity and impedance matrix sensitivity. The theory posted in this dissertation is tested by the FEM software ANSYS and the software AAS programmed by author.

在前几章的基础上，通过结构声辐射的模态理论对结构的声辐射的机理进行了深入地探讨，针对目前声辐射模态的研究对象主要是简单的板和梁类结构，提出了一种计算复杂结构声辐射模态的方法，利用前两章研究所得的结论，将边界元方法与广义特征值的理论结合起来研究了复杂结构的声辐射模态与声辐射效率，先将结构的声辐射功率表示为一个正定的厄米特二(来源：ABb7C论文0909网www.abclunwen.com)次型，运用广义特征值分解求解了复杂结构的声辐射模态，然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性，求解了复杂结构的声辐射效率，最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。

In orde to obtain system optimization in high efficiency production and operation safety, the microcosmic problem of goaf treatment was brought into the creative design of mining method and the synergism of two problems was studied. Firstly, in view of the occurrence characteristics and mining conditions of catacalstic ore section of orebody No. 105 in Gaofeng mine in Guangxi province, considering the adaptability to different scale goafs in the ore section, based on mining environment reconstructing idea and continuous mining mode, a new mining method (mining environment reconstructing non-pillar sublevel-strip continuous mining method) was put forward. Then, some repr, esentative goafs were selected and their stabilities were calculated by discrete element method on the basis of differences of goaf scale, surrounding conditions and situ stress field. At last, the mining layout was adjusted on the basis of goafs stability analysis and the goafs were adjusted as a part of cutting engineering, blasting space or stope, so as to determine all kinds of goafs treatment schemes.

摘 要：为在生产高效和作业安全上取得系统整体最优，将碎裂矿段的空区处理微观问题纳入采矿方法创新设计宏观问题中，开展2种问题的协同研究：首先，针对广西高峰矿105号矿体碎裂矿段的赋存特点和开采技术条件，考虑对各种规模空区适应性，基于采矿环境再造和连续采矿理论，提出采矿环境再造无底柱分段分条连续采矿法；然后，根据采空区规模、围岩状况和原岩应力场等条件的差异，在所有采空区中选择具有代表性的空区，运用离散元程序对其稳定性进行计算分析；最后，在稳定性分析的基础上，灵活调整开采布局，将采空区调整为部分切割工程、自由爆破空间或采场，从而确定出各种规模空区的处理方案。

The general condition for athermalizing an optical system when the object surface is at finite or infinite distance is deduced in this paper, and the principle and design method of employing a diffractive optical element to athermalize and achromatize an optical system with normalized T-C chart are expanded.

推导了物面位于有限远和无限远时，实现热补偿的通用条件；并阐述了利用归化T-C 图设计消热差和消色差的红外光学系统的原理和方法。

The general condition for athermalzing an optical system when the object surface is at finite or infinite distance is deduced in this paper, and the principle and design method of employing a diffractive optical element to athermalize and achromatize an optical system with normalized T-C chart are expounded.

本文推导了物面位于有限和无限距离时实现光学补偿的通用条件，论述了利用归化T-C图设计热补偿和消色差红外光学系统的原理和设计方法，给出了8-12μm波段内、焦距123mm、相对口径F/2.5在20-60℃温度范围内的折衍混合红外光学系统的设计结果和理论评价结果，所述的设计方法可方便地推广到前视红外系统中。

Key words: coupled structure-acoustic systems; acoustic pressure; optimization; finite element method

以一矩形板结构一立方体声场耦合系统为实例，得到了优化的结构厚度分布。

The stress distribution of adhesively-bonded metal/metal single lap joints under tensile shear loading is analysed using elastic-plastic finite element method .The influence of lap length on the strength of adhesively bonded metal joints which are bonded with phenolic resin and acrylic resin respectively is discussed in detail. It is shown that adhesive has great influence on the stress distribution of the lap region. With the increment of lap length, the stress concentration of adhesive layer decreases.

本文在对国内外关于金属-胶层复合材料接头力学性能数值研究及发展现状进行综述的基础上，运用有限元法并结合实验手段主要研究了胶接接头承载后的力学行为，综合考虑了几何尺寸和物性参数对接头强度和应力分布的影响，并运用层次分析法对胶接质量进行综合评估，综合考虑接头形式，制造工艺，操作人员素质等因素的影响。

The mechanical behaviour of intersection of horizontal adit and main tunnel in Wanxian to Liangping expressway in Southwest China is studied by using 3D finite element numerical simulation method and in-situ test.

针对高速公路主隧道与车行横通道组成空间交叉结构，采用现场实测以及三维有限元数值模拟研究手段，进行了结构施工力学研究。

By means of modal analysis and the finite element method, the dynamic characteristic of agitator was researched in this paper.

试验模态分析广泛应用于工程领域，是研究一个系统的振动特性主要途径之一。

Chapter 1 presented the histories of airship and nonlinear finite element method.

文中第一章总结回顾了飞艇研究历史及非线性有限元法的发展过程。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。