Electromagnetic–thermal–structural coupling analysis of the ITER edge localized mode coil with flexible supports

In a fusion reactor, the edge localized mode（ELM） coil has a mitigating effect on the ELMs of the plasma. The coil is placed close to the plasma between the vacuum vessel and the blanket to reduce its design power and improve its mitigating ability. The coil works in a high-temperature,high-nuclear-heat and high-magnetic-field environment. Due to the existence of outer superconducting coils, the coil is subjected to an alternating electromagnetic force induced by its own alternating current and the outer magnetic field. The design goal for the ELM coil is to maintain its structural integrity in the multi-physical field. Taking as an example the middle ELM coil（with flexible supports） of ITER（the International Thermonuclear Fusion Reactor）, an electromagnetic–thermal–structural coupling analysis is carried out using ANSYS. The results show that the flexible supports help the three-layer casing meet the static and fatigue design requirements. The structural design of the middle ELM coil is reasonable and feasible. The work described in this paper provides the theoretical basis and method for ELM coil design.

Thermal-Structural Coupled Analysis of ITER Torus Cryo-Pump Housing

An ITER torus cryo-pump housing （TCPH）, which encloses a torus cryo-pump, is connected to a vacuum vessel （VV） by a set of associated double bellows. There are complicated loads due to two different operating states （pumping and regeneration） and foreseeable accidents with the cryo-pump. This paper describes a thermal-structural coupled analysis of the present TCPH according to tho allowatfle stress criteria of RCC-MR, in which the worst cases and outcomes of various load combinations are obtained. Meanwhile, optimization of the structure has been carried oul, to obtain positive analysis results and an adequate safety margin.

Geometric nonlinear formulation for thermal-rigid-flexible coupling system

This paper develops geometric nonlinear hybrid formulation for flexible multibody system with large deformation considering thermal effect. Different from the conventional formulation, the heat flux is the function of the rotational angle and the elastic deformation, therefore, the coupling among the temperature, the large overall motion and the elastic deformation should be taken into account. Firstly, based on nonlinear strain-displacement relationship, varia- tional dynamic equations and heat conduction equations for a flexible beam are derived by using virtual work approach, and then, Lagrange dynamics equations and heat conduction equations of the first kind of the flexible multibody system are obtained by leading into the vectors of Lagrange multiplier associated with kinematic and temperature constraint equations. This formulation is used to simulate the thermal included hub-beam system. Comparison of the response be- tween the coupled system and the uncoupled system has re- vealed the thermal chattering phenomenon. Then, the key parameters for stability, including the moment of inertia of the central body, the incident angle, the damping ratio and the response time ratio, are analyzed. This formulation is also used to simulate a three-link system applied with heat flux. Comparison of the results obtained by the proposed formulation with those obtained by the approximate nonlinear model and the linear model shows the significance of con- sidering all the nonlinear terms in the strain in case of large deformation. At last, applicability of the approximate non- linear model and the linear model are clarified in detail.

深中通道钢壳-混凝土组合沉管浇筑变形研究

深中通道沉管管节采用钢壳-混凝土组合结构形式,通过向空钢壳浇筑混凝土预制而成。为评估沉管管节施工后的整体变形,建立了热-结构顺序耦合的分析框架,基于ANSYS APDL及UFPs二次开发模块,分别建立了考虑水化度、日照辐射、大气温度变化的精细温度场模型和考虑混凝土硬化及收缩特性的结构分析模型。通过对足尺管节的温度及应变模拟结果与监测数据的对比,验证了有限元模型的可靠性。在此基础上,分析了日照辐射、大气温度变化等对于管节温度场的影响,同时分析了管节的整体变形模式,以及温度效应、混凝土收缩及自重三种因素对管节整体横向、纵向及竖向变形的影响。结果表明:管节施工过程的温度场表现为时变和空间分布的特征,格仓边部温度受外界气温变化和日照辐射的影响存在周期性波动,而格仓中部温度峰值主要受混凝土自身水化放热特性的控制;管节最终表现为顶板横向及纵向内收,竖向下挠,底板横向及竖向变形不显著;太阳辐射对于结构温度场影响较日气温变化更显著,建议在混凝土温度峰值预测中予以考虑,而日气温变化可采用日平均气温值予以简化;温度效应及材料收缩对管节横向及纵向整体变形影响显著,自重因素导致的变形在横向及纵向的比例为44.3%、11.7%,而在竖向所占比例达92.5%,因而温度效应及材料收缩在管节横向及纵向变形分析中不可忽视;该分析方法可适用于大体积混凝土等结构的温度效应的预测和评估。

7FDL-16柴油机气缸盖热结构耦合应力分析

通过CATIA软件进行三维建模,利用Space Claim模块提取流体域,在Fluent模块设置流体边界条件并仿真流动,先后导入Ansys Workbench稳态热和静应力分析模块,设置热边界条件和应力载荷,得到气缸盖的温度场以及热结构耦合应力分布云图。热结构耦合应力分析可得:热应变最大处在火力面鼻梁区,最大变形量为0.002 1 mm,应力最大处在两排气门之间的鼻梁区,最大应力值为398 MPa,安全系数为2.71,满足实际结构工作的要求标准。

Thermal–structure coupling analysis and multi-objective optimization of motor rotor in MSPMSM

With the high speed, the rotor of magnetically suspended permanent magnet synchronous motor(MSPMSM) suffers great thermal stress and mechanical stress resulting from the temperature rise problem caused by rotor losses, which leads to instability and inefficiency.In this paper, the mechanical–temperature field coupling analysis is conducted to analyze the relationship between the temperature field and structure, and multi-objective optimization of a rotor is performed to improve the design reliability and efficiency. Firstly, the temperature field is calculated by the 2 D finite element model of MSPMSM and the method of applying the 2 D temperature result to the 3 D finite element model of the motor rotor equivalently is proposed. Then the thermal–structure coupling analysis is processed through mathematic method and finite element method(FEM),in which the 3 D finite element model is established precisely in a way and approaches the practical operation state further. Moreover, the impact produced by the temperature and structure on the mechanical strength is analyzed in detail. Finally, the optimization mathematical model of the motor rotor is established with Sequential Quadratic Programming-NLPQL selected in the optimization scheme. Through optimization, the strength of the components in the motor rotor increases obviously and satisfies the design requirement, which to a great extend enhances the service life of the MSPMSM rotor.

Synthesis, Crystal Structure and Properties of a New Zn(II) Coordination Polymer Constructed from 2,3-Pyridine Dicarboxylic Acid and 1,1′-(1,4-Butanediyl)bis(imidazole)

A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436（3）, b = 16.988（5）, c = 12.106（4）, β = 92.204（5）°, V = 1733.6（9）3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F（000） = 864, μ（MoKa） = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn（II） is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn（II） ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.

Thermally Induced Vibration Analysis of Flexible Beams Based on Isogeometric Analysis

Spacecraft flexible appendages may experience thermally induced vibrations(TIV)under sudden heating loads,which in consequence will be unable to complete their intended missions.Isogeometric analysis(IGA)utilizes,in an isoparametric concept,the same high order and high continuity non-uniform rational B-splines(NURBS)to represent both the geometry and the physical field of the structure.Compared to the traditional Lagrange polynomial based finite element method where only C0-continuity across elements can be achieved,IGA is geometrically exact and naturally fulfills the C1-continuity requirement of Euler–Bernoulli(EB)beam elements,therefore,does not need extra rotational degrees-of-freedom.In this paper,we present a thermally induced vibration analysis framework based on the isogeometric method where thermal and structural behaviors are coupled.We fully exploited the higher order,higher continuous and geometric exactness of the NURBS basis with both benchmarks and sophisticated problems.In particular,we studied the thermally induced vibrations of the Hubble Space Telescope(HST)solar panel where main factors influencing thermal flutters are studied,and where possible improvements of the analytical reference methods are discussed.Additionally,thermally induced vibrations of the thin-walled lenticular tubes are studied and two new configurations of the tube are proposed to effectively suppress the thermally induced vibrations.Numerical examples of both benchmarks and sophisticated problems confirm the accuracy and efficiency of the isogeometric analysis framework for thermally induced vibration analysis of space structures.

制动盘仿生表面热-结构耦合研究

汽车在紧急或频繁制动下因制动盘散热性能较差,易发生制动性能热衰退现象,借鉴蝴蝶翅膀鳞片表面微观结构优异的散热性能,构建了制动盘表面微结构仿生物模型。根据热分析理论,对仿生制动盘进行热–结构耦合的温度场仿真分析,研究不同仿生制动盘的散热情况,对散热性能最佳的仿生制动盘表面进行倒角处理,并进行温度场仿真分析。研究表明:在制动过程中非光滑制动盘表面温度高于光滑制动盘,在制动结束后,非光滑制动盘表面温度下降迅速,最终温度低于光滑制动盘模型。停滞散热阶段后,具有圆形凹槽及倒角为45˚的制动盘表面温度最低,可以有效地降低汽车后续制动过程中制动性能热衰退现象。

基于流-热-固耦合分析的数值模拟及结构优化

为解决等径T型管路应力过大问题,提出一种基于流-热-固耦合分析方法的优化方法对等径T型管结构进行优化。首先,基于流、固力学理论建立T型管多场耦合的数学模型和物理模型,对T型管内流体的速度温度变化情况和管路的等效应力的分布情况进行仿真模拟,在仿真结果的基础上对管路进行结构优化。仿真结果表明:冷热流体的压力差会导致流体产生逆流现象,从而导致管路的上游区等效应力值增大。等径T型管的最大等效应力值出现在主支管交汇的下游内壁面处。优化后管路内壁面最大等效应力值下降约14%,可以有效地延长管路的使用寿命。该方法对提高气体管路设计的可靠性具有一定的实践意义。

RF-thermal-structural-RF coupled analysis on a travelling wave disk-loaded accelerating structure

The travelling wave （TW） disk-loaded accelerating structure is one of the key components in normal conducting （NC） linear accelerators, and has been studied for many years. In the design process, usually after the dimensions of each cell and the two couplers are finalized, the structure is fabricated and tuned, and then the whole structure RF characteristics are measured by using a vector network analyzer. Before fabrication, the whole structure characteristics （including RF, thermal and structural ones） are less simulated due to the limited capability of currently available computers. In this paper, we described a method for performing RF-thermal-structural-RF coupled analysis on a TW disk-loaded structure using only one PC. In order to validate our method, we first analyzed and compared our RF simulation results on the 3 m long BEPC Ⅱ structure with the corresponding experimental results, which shows very good consistency. Finally, the RF-thermal-structure-RF coupled analysis results on the 1.35 m long NSC KIPT linac accelerating structure are presented.

CSNS-Ⅱ靶站质子束窗结构设计与优化分析

中国散裂中子源(CSNS)靶站质子束窗位于环到靶站输运线(RTBT)与靶站交接面,起到隔离加速器高真空和靶站氦气环境的作用。随着束流功率提高,目前质子束窗单层膜结构形式已无法满足CSNS-Ⅱ500 kW的高功率需求,因此开展CSNS-Ⅱ质子束窗研制,设计出双层膜中间通水的冷却结构,完成质子束窗双层膜的薄膜半径、薄膜厚度、水冷槽长度与宽度、对流换热系数等各参数对质子束窗温升与热应力的影响分析。通过冷却水需求分析得出,冷却水流速需大于15 L/min。通过质子束窗主体的流固耦合分析,消除箱体内部死水区域。最终优化后质子束窗薄膜位置最高温度47.8℃,薄膜位置最高热应力30.758 MPa。通过FLUKA软件对质子束窗材料的辐照损伤性能进行分析,在每年5000 h工作时长、500 kW高功率束流的辐照下,辐照损伤DPA计算值为1.285 DPA,质子束窗的安全使用寿命在7年以上。

Research on numerical welding experiment of a thick spherical shell structure

In this paper, in order to predict the residual deformation of thick spherical structure, a welding program is compiled in APDL language based on Ansys and a numerical welding experiment of a welding example is carried out. The temperature field of welding was simulated firstly, then a thermal-structure coupling analysis was carried out, and at last the residual stress and deformation after welding were got. After that, the numerical experiment result was compared with physical experiment one. The comparative analysis shows that the numerical simulation fits well with physical experiment. On the basis of that, a three-dimensional numerical experiment of a thick spherical shell structure was carried out to get the changing rule of stress and deformation of a thick spherical shell structure during welding. The research is of great value to the prediction of residual deformation and high precision machining.

斜面型自补偿油封的热-结构耦合分析

传统唇形油封在使用过程中,存在不耐高温、耐磨性能差、摩擦生热高、使用寿命短等问题,为此,提出了一种使用斜面型自补偿油封代替传统的唇形油封的方法,利用数值分析软件进行了油封的热-结构耦合分析,探究了摩擦温度对油封热应力的影响规律。首先,利用数值分析软件建立了斜面型自补偿油封的动力学模型,采用热-结构耦合的分析方法,进行了油封温度场的求解;然后,引入温度场对油封应力进行了求解,对比分析了相同工况下唇形油封和斜面型自补偿油封温度场的区别;最后,搭建了高压高转速密封实验台,使用PT100温度传感器、瞬态液晶测量等新技术,进行了密封点-面测温,开展了斜面型自补偿油封温升特性的实验研究。实验结果表明:斜面型自补偿油封摩擦温升较唇形油封低,唇形油封的高摩擦生热性及材料的高弹性造成了唇形油封热应力集中,影响了唇形油封的使用寿命;在相同工况下,斜面型自补偿油封较唇形油封摩擦温升低,转子转速每增加1000 r/min,唇形油封的温度平均上升16.9%,斜面型自补偿油封的温度平均上升14.1%;转子转速在3000 r/min~4000 r/min时,斜面型自补偿油封稳定时的温度比唇形油封低21.1%~26.3%。研究结果表明:在相同工况下,斜面型自补偿油封的温升要低于唇形油封;斜面型自补偿油封的低摩擦温升,对于提高密封的使用寿命具有指导意义。

基于ANSYS的平板焊接热-结构耦合场数值模拟

采用ANSYS软件对平板焊接过程进行了数值模拟分析,通过APDL语言编写程序,建立平板对接有限元模型,利用体生热率热源模型和“生死单元”法动态模拟了焊缝金属的熔覆过程,最后对焊接过程的温度-应力耦合场进行了模拟。后处理时,通过选择不同方向上的路径进而得到对应的热结构耦合场中的温度变化曲线和残余应力分布曲线,结果显示与实际焊接过程规律相符,为工程实际中焊接模拟的可靠性分析提供了有益参考。

喷管分离流流动-热-结构顺序耦合数值模拟及试验研究

针对大膨胀比喷管气流分离状态下喷管所受的复杂载荷,采用数值方法分析喷管结构。利用有限体积二阶迎风插值格式及SST涡耗散湍流模型,结合二层增强型壁面函数,求解N-S方程、热传导方程。采用流固耦合的流动与换热模型,流场与结构温度场互为边界条件交互数据,实现了流场解算与温度场解算的耦合数值分析。应用有限元方法对给定的温度场及压力载荷作用下的结构进行了瞬态静力分析,实现了流动-热-结构的顺序耦合。采用此计算模型对轴对称拉瓦尔喷管进行了数值模拟,发现在大膨胀比下喷管发生气流分离,经分离处的斜激波后气流温度梯度及压力梯度变化较大,导致该区域应力较大。为验证模型的准确性,开展了试验研究,测得的气流分离位置和计算得到的分离位置很好的符合,说明了计算方法的有效性。

船用机械密封环热-结构耦合有限元优化计算研究

以小锥度的收敛间隙为优化原则,以最大接触压力作为目标函数,以静环端面的磨损裕度为设计变量,采用一阶优化法进行机械密封环热-结构耦合有限元优化计算。优化结果表明:过大的磨损裕度使密封端面易产生外侧接触的倾向,密封系统稳定性差,外侧易出现严重磨损;过小的磨损裕度使密封端面内侧接触压力明显增大,易出现局部过度磨损现象。采用此优化方法,可以在保证内接触条件下提高密封端面接触均匀性和机械密封的热力学性能,对机械密封环的设计,制造及密封环热力状态的进一步研究具有重要的意义。

可展桁架天线热-结构耦合分析

利用热传导-辐射理论建立方程,同时引入可展桁架天线所处的轨道条件,计算出可展桁架抛物面天线在轨运行时不同时刻的温度场;考虑结构非线性,建立结构热变形计算方程,并将热分析与结构分析进行耦合.利用Fortran语言,编制基于上述理论的有限元程序,计算出可展桁架天线在轨运行时不同时刻天线的温度场和热变形,以及不同时刻反射面的形面误差均方根(RMS).采用热-结构耦合分析方法对算例的分析表明,该方法可实现可展桁架天线从热分析到结构分析的直接转化和耦合,可用于指导可展桁架天线的结构设计和热控制设计.

仿生制动盘热-结构耦合场的ANSYS仿真分析

汽车制动盘在紧急制动下易发生热衰退导致的制动性能失效现象,从而引起事故的频繁发生.基于昆虫体表因具有非光滑表面结构而表现出的耐磨特性,构建了制动盘表面微结构仿生模型.根据热分析理论,对模型进行了不同初始速度下摩擦制动过程中瞬态温度场的仿真分析,研究了仿生制动盘表面微结构对散热性能的影响.结果表明:表面具有微凹坑结构的制动盘表现出较好的散热性能,利于制动性能的提高;这源于凹坑结构更易储存空气,能够实现制动盘与周围空气的快速换热,利于制动热量的迅速散失,从而有效降低因温度骤然升高而引起的热疲劳和热磨损.

重载减速箱有限元热-结构耦合分析研究

针对重载减速箱存在的热载荷引起的热变形问题,应用有限元热-结构耦合分析方法,对箱体结构进行热态特性分析,给出箱体的稳态温度场分布,将分析结果作为箱体热-结构耦合分析的边界条件,建立了耦合分析模型,计算出箱体在热和结构载荷共同作用下箱体的应力分布和位移云图。研究结果表明,重载减速箱变形是结构载荷与热载荷共同作用的结果,其中热载荷是控制箱体变形,保证重载齿轮传动精度与可靠性不可忽略的重要因素。