查询词典 calculating element

A method to calculating maneuver for special point maneuver strategy is developed based on the facts that are single objective of every maneuver and tiny correction for orbit inclination and right ascension of ascending node. The basic idea of the method is disassembling calculating for phasing and orbit plane correction, and the equation for calculating maneuver is derived.(2) A method for determining the optimal collision avoidance maneuver is developed, and the two phasing orbits strategy is developed to avoid collision with debris.

1研究了远距离导引的特殊点变轨策略，针对特殊点变轨策略每次机动目标单一和轨道面修正为小量的特点，提出了将轨道面内调相与轨道面修正分解计算的策略，推导了采用高精度轨道模型的调相和轨道面修正机动计算公式；(2)研究了远距离导引段飞行器规避空间碎片的机动问题，提出了一种双调相轨道机动策略，并给出了碰撞规避机动的计算公式。

The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.

文中对汽车碰撞安全性的设计理论和方法进行了归类和总结，其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等；重点介绍了碰撞有限元法的基本理论和有关算法，涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等，探讨了有限元计算中的材料模型参数获取技术，开发了相应的材料试验装置及材料模型参数反求软件，在此基础上进行了基本的碰撞仿真算例和试验对比研究；文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性，指出了设计薄壁吸能构件时需要考虑的几个主要影响因素，即焊点、壁厚、横截面和预变形等；在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究，提出了吸能转向机构和自适应安全气囊的仿真研究方法；文中最后探讨了整车碰撞性能的设计与改进方法，提出了以理想碰撞特性为目标，采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法，并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究，所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车，研究结果表明，本文所提出的设计与改进方法是适用而有效的，具有重要的工程实用意义和价值。

Shadow effect can not be neglected for thermal analysis of spacecraft,Accroding to the angle between solar light and antenna orbit plane and its orbit location,analytical geometry method was used for accurately calculating solar radiation heat flux distribution of reflector surfaces.To analyze the temperature field under heat flux,the formulations of net radiation flux density between two gray elements and the net flux density of gray surface under external thermal flux were deduced.Based on the characteristic of space environment,the nonlinear temperature distribution in transverse direction of reflector shell self radiation were considered,the finite element formulations were given for orthogonal material layered shell by Galerkin method.A layered element including a inner heat source layer was proposed,and the finite element formulation expressed by DOF of the inner heat source layer were put forward with temperature and heat flux boundarys between adjacent layer.

单馈反射面赋形天线是未来星载天线发展的一个重要形式，分析了基于物理光学、几何光学和几何绕射理论的理想反射面辐射场；介绍了基于几何光学的反射面天线赋形方法；针对赋形过程中辐射场的快速分析要求，比较分析了基于物理光学的Fourier-Bessel和Jacobi-Bessel级数展开方法以及GB展开分析方法；利用GB展开快速分析方法在20GHz频率下对0.6m口径的天线进行赋形分析，实现中国大陆的30dB增益覆盖，通过数值计算研究了固定增益期望下的口径尺寸随频率的变化，以及频率为20GHz的不同尺寸天线赋形后的覆盖目标区域最大增益的变化情况。

Research on self - organization of complex system on element periodic table ;2. The formula can be used in calculating thirty quantitives or more of element and its compounds in the same tribe of the element periodic table .

将同系因子1／N用于元素周期表，以N为周期序数，P作为各元素或其化合物的性能，利用公式P＝a＋b／N对周期表中各元素及化合物30多种性能进行拟合，得到了良好的结果。

A C++ program is developed for composing the stiffness matrix of the temperature field, saving it in changing bandwidth method and calculating the linear algebraic function group through using the Gauss eliminating method. A module for drawing the color fringe of tire temperature field is created, which makes the result more visual. Taking the 9.00-20 cross-ply tire on CA1092 as an example, the finite element numerical simulation analysis of automobile tire 2-D steady temperature field is completed. Through comparing the result with the analysis data by ANSYS, this software is proved to be capable of the modeling, calculating and post-processing of FEA of automobile tire 2-D steady temperature field.

采用C++语言完成了温度刚度矩阵的总体合成及其一维变带宽存贮，以及线性代数方程组高斯消去法求解等工作，采用C++语言实现了汽车轮胎二维稳态温度场云纹图的绘制，使得计算结果更加直观，也更能形象地显示汽车轮胎二维稳态温度场的分布状况，以CA1092（原CA142）五吨载货汽车用9.00-20尼龙斜交胎为例，进行了汽车轮胎二维稳态温度场有限元数值仿真分析，通过与ANSYS分析结果进行比较，说明所开发的有限元建模、求解以及后处理软件能够用于汽车轮胎二维稳态温度场有限元分析。

In the end, the result derived from finite element calculating program and actual experiment war compared in detail which demonstrates the stress calculating method pr...

分析结果表明：采用的计算方法及所编制的解算程序的计算结果与实验数据吻合，具有一定的实用价值。

The design and drilling methods include selecting a formation to be drilled, calculating a desired DOC and the strength of the formation, and calculating a height or thickness of a bearing element that may limit the DOC and the unit force applied to the formation.

设计和钻井方法包括选择待钻的地层、计算期望的DOC和地层强度和计算可限制DOC和施加到地层的单位力的支承元件的高度或厚度。

In this paper, the 3-D finite element relocating mesh method is used to calculate the temperature field and the thermal creep stress field of spillway dam and mid level outlet dam in certain roller compacted concrete gravity dam, sensitivity analysis have been down with different parameters, such as placing temperature, the location of cooling pipe, cooling temperature, time for water supply, ascended-layer of concrete, intermissive time and different placing time, and the commendatory construction scheme have been put forward in such analysis; according by the test result on the two scheme of concrete aggregate combination (basalt as coarse aggregate and limestone as fine aggregate, basalt as coarse aggregate and basalt as fine aggregate), simulation analysis on temperature field and thermal creep stress field of the commendatory construction scheme have been down, and analysis have also been down on temperature field and thermal stress field of the two different aggregate combination, the result indicates that the spillway dam and mid level outlet dam which adopted these two aggregate combination can both satisfy the require of design crack resistance in concrete, furthermore limestone as fine is better than basalt as fine aggregate; the effect of summer water storage and winter water storage on the temperature field and thermal stress field have been analyzed, comparing with winter water storage, in summer water storage scheme the maximum tensile stress at abnormal concrete in upstream fill is decreased by 0.1～0.3MPa and there are no evidence change of the maximum tensile stress at other parts, which indicate that summer water storage is avail for the crack resistance of upstream fill; according to the simulation calculating result and comparing temperature simulation calculating results and temperature controlling measures of some similarity projects both completed and construction, synthesis appraise have been carried to the design temperature controlling measures of dam, and the temperature controlling measures of this project have been brought forward, all these have great reference value on the design of temperature controlling measures and the optimization of the construction scheme.

本文采用三维有限元浮动网格法仿真计算程序，对某碾压混凝土重力坝的溢流坝段和中孔坝段分别进行了三维有限元温度场和温度徐变应力仿真计算分析，对浇筑温度、冷却水管的布置方式、冷却水温、通水时间、浇筑升程和间歇时间、不同开始浇筑日期等参数进行了敏感性分析，在此基础上提出了推荐的施工方案；根据两种骨料方案(玄武岩粗骨料+灰岩细骨料方案；玄武岩粗骨料+玄武岩细骨料方案)的混凝土性能试验研究成果，对推荐的施工方案进行了温度场和温度徐变应力仿真计算，并对比分析了两种不同骨料情况下的温度场和温度应力，结果表明溢流坝段及中孔坝段采用上述两种骨料均能满足混凝土的抗裂设计要求，且灰岩细骨料优于玄武岩细骨料；计算分析了夏季蓄水和冬季蓄水对坝体温度场和温度应力的影响，夏季蓄水方案与冬季蓄水方案相比，坝体上游变态混凝土区域最大拉应力小0.1～0.3MPa，其他部位最大拉应力无明显变化，夏季蓄水对坝体上游面混凝土的抗裂有利；根据仿真计算成果并通过比较国内一些已建和在建的类似工程的温度仿真计算成果及采取的温控措施，对大坝的设计温控措施进行了综合评价，并提出了该工程的温控措施，对温控设计和优化施工方案具有重要参考价值。

In the second chapter, elementary theories and ideas of one step forming inverse approach were described and warped modification method, implemented by Cook, was introduced into one step forming simulation and based on idea of surface spreading; new quadrilateral element modification arithmetic was put forward. By spreading warped quadrilateral onto plane in local coordinate system, a plane quadrilateral element whose shape and area were equal to original warped quadrilateral element was gotten and internal force vectors of four nodes and stiffness matrix of elements were improved to increase precision of simulations on this plane element.

第二章从一步成形逆有限元法的基本理论和思想出发，将Cook基于弹性理论的四边形单元的翘曲修正算法引入基于塑性的一步成形，并且基于曲面展开的思想，本文提出一种新的四节点单元翘曲修正方案，通过把翘曲的单元展开的方法在局部参考系中得到一个与实际翘曲单元的形状与面积非常接近的平面单元，在该平面单元中进行单元刚度及内力向量的计算，进一步改善模拟结果的精度。

Firstly it describes the development ,basic principle and application and propagation characteristic of mobile channel , then investigates the system structure of DAB transmitter and receiver separately and the key technology of realization of the digital audio broadcast system.And then discusses the system component of FFT －the demodulation module of OFDM .The 409- points FFT module employs a radix-4 decimation-in-frequency algorithm, includes arithmetic element , read and write address element ,twiddle factor element and control element , is realized by FPGA. In the end , the result is verified in the matlab .

首先概述了OFDM的发展、基本原理和应用以及移动信道的传播特性，接着分别研究了数字音频广播接收机和发射机的系统结构，以及数字音频广播系统实现的关键技术，然后详细论述了OFDM解调模块FFT的系统结构，主要研究了4096点FFT采用基－4按频率抽取实现的算法，整个FFT模块包括了运算单元、读写地址单元、旋转因子单元以及控制单元，并且在FPGA中进行了硬件实现，并在matlab环境下对结果进行了验证。

Putt your way through 36 fun-filled holes of minigolf on 3D designed courses with elevated greens, bunkers, bridges and water hazards, among other crazy obstacles.

您的推杆方式，通过36个有趣的填孔迷你的三维设计的课程，以提升绿党，掩体，桥梁和水的危害，除其他疯狂的障碍。

Some participles can be used either as attributes or as predicatives.

有些分词既可当定语用，也可当表语用。