查询词典 thermal element

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。

The results indicate that the effect of alloying elements V and Cr on mechanical properties at room-temperature, creep behavior and microstructures are similar. With increasing contents of V and Cr, their mechanical properties produce little change, the creep resistant property decreases and microstructure grows, which is mainly due to their characteristics of β-stability element and smaller atomic radius compared with Ti. On the contrary, the effects of V and Cr on the thermal stability are quite different. With increasing V content or decreasing Cr content the thermal stability for the alloy becomes better, which may be due to the different solution characteristics of V and Cr element in titanium alloy that V belongs to isomorphous β-stability element and Cr belongs to eutectoid β-stability element.

结果表明：合金元素V和Cr对Ti40合金室温力学性能、蠕变行为和组织的影响具有相似性，即随V和Cr含量的降低，合金室温综合力学性能变化不明显、抗蠕变能力减弱、组织粗化：这与V和Cr同属于β稳定元素、且原子半径都小于Ti原子有关；而V和Cr对于热稳定性能的影响则完全相反，V含量的增加或Cr含量的降低含金热稳定性能优化，其主要原因可能与V属于同品型β稳定元素而Cr属于共析型β稳定元素有关。

In chapter 2, a finite element model for the composite sandwich plates is developed, based on the Zig-Zag deformation assumption and the first order shear deformation theory, and the finite element buckling analysis governing equations for the plates under mechanical, thermal and/or thermal-mechanical mixed loads are deduced respectively. By Von-Karman nonlinear deformation relations and Total Lagrange formulation, an incremental governing equation for postbuckling analysis is established and a corresponding effective computational scheme is presented..

第二章首先建立了基于Zig-Zag截面变形假定和Mindlin一阶剪切理论的夹层板有限元分析模型，分别推导了夹层板机械力、热载和热—机械力耦合屈曲分析的有限元列式和相应的屈曲前以及屈曲临界状态的平衡方程，基于Von-Karman大挠度理论，采用增量形式的全局lagrangian法推导了复合材料夹层板增量形式的几何非线性有限元离散平衡方程，给出了一种有效的非线性平衡方程的迭代求解格式。

SiC ceramic has been extensively applied in precision bearings, sealing element, steam-turbine rotor, burner nozzle, heat interchanger parts, atomic reactor materials and etc. because of its excellent properties in high temperature mechanical properties, antioxidatio, abrasion resistance, thermal stability, smaller coefficient of thermal expansion, larger thermal conductivity, hardness, thermal shock and chemical corrosion.

SiC陶瓷具有优良的高温力学性能，抗氧化性强、耐磨损性好、热稳定性佳、热膨胀系数小、热导率大、硬度高以及抗热震和耐化学腐蚀等优良性能，被广泛应用于精密轴承、密封件、气轮机转子、燃烧喷嘴、热交换器部件及原子热反应堆材料等，并日益受到人们的重视，应用前景十分广阔。

Secondly, ANSYS is used to compute the thermal filed of air-core reactor. A coupled magnetic-circuit-thermal finite element model is proposed for thermal analysis. Finally, the distribution of the thermal field and the maximal temperature are given.

对干式空心电抗器的温度场进行了有限元分析，建立磁场-电路-温度场的耦合计算模型，得到空心电抗器的稳态温度场分布以及最高温度值。

So the braking prescription should be performed strictly, furthermore, the sudden and urgent braking should be avoided to the best of our abilities.In the end, the thermal fatigue lives were evaluated by the finite element method. It was proved that the thermal fatigue life of improved steel (ZG35CrMoRE) was higher than that of the formers. It was also found that the quantitative evaluations of the thermal fatigue lives of brake disc were acquirable, by putting the equivalent plastic strain, which was analyzed with finite element methods, and the material mechanical property parameters into the formula of Manson-Coffon to calculate its lives. Therefore, theoretical method can be provided to develop new brake disc steel and to prolong its lives.

为了进一步提高刹车鼓的使用寿命，对新试制的钢种进行了热疲劳寿命评估，验证了改进后的钢种在相同的使用工况下具有更高的热疲劳寿命；评估结果还表明利用有限元数值分析计算相应的等效塑性应变，结合材料力学性能参数，代入Manson-Coffin热疲劳寿命公式可以对刹车鼓的热疲劳寿命做出定量评估，从而为刹车鼓用钢的研制和刹车鼓寿命的提高提供了理论依据。

In the second part, the theory of numerical simulation is introduced, including description of body configuration, elastic-plastic large deformation constitutive equation and finite element formula. It is followed by the derivation of equation from the basic theory of elastic-plastic deformation. The solution to temperature field, thermal stress, thermal strain, equivalent effective stress and equivalent strain is achieved then. In addition, we exposit the relation between machine load and thermal load in coupling analysis.

介绍了物体的构形及其描述，弹塑性大变形的本构方程、有限元列式；并进一步论述了弹塑性变形的基本理论，推导了弹塑性方程组；阐述了温度场的求解、热应力及热应变的理论概要，说明了等效应力与等效应变，并进一步阐明了在热力耦合分析中，机械负荷与温度负荷之间的关系；此外，还简介了Marc AutoForge程序结构的特点。

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。

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。

This paper discusses the problems of measuring for deflection of thermal bimetal element and puts forward a kind of method for optical measurement of thermal bimetal element.

讨论热双金属片挠度的测量问题，提出一种热双金属片挠度的光学测量方法。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。