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为研究多物理参数(耦合系数、电子热导率、电子热容、晶格热容)同时随温度变化对短脉冲激光辐照金属材料产生温度场分布的影响,基于双温耦合理论,建立了短脉冲激光辐照金属材料金的加热过程的有限元求解模型。在同时考虑脉冲激光的空间、时间分布和多参数同时随温度变化的情况下,得到短脉冲激光辐照金属材料金激励产生的温度场二维瞬态分布,并进一步比较了多物理参数同时随温度变化和采用室温物理参数两种情况下温度场分布的区别。数值结果表明:多物理参数同时随温度变化使电子温度和晶格温度的上升变快,最大值变大,而且使得材料中激光穿透直接辐照到的区域温度变高。 相似文献
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激光加热温度场物理分析 总被引:8,自引:1,他引:7
本文采用数值模拟法分析了激光加热温度场分布,此方法简单具有一般性,没有解析法通常所有的局限性。分析了材料表面热辐射,激光作用时间及功率密度对温度场分布的影响,作者认为此数值模拟结果是符合实际的。 相似文献
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基于ANSYS的脉冲激光辐照石英玻璃的温度场数值模拟 总被引:2,自引:0,他引:2
采用有限元仿真软件ANSYS 12.0对脉冲功率激光辐照石英玻璃建立了热力学模型,对其表面温度场进行了数值模拟,得到了在不同激光功率密度下的瞬态温度场分布,并对模拟结果进行了分析和研究,为激光辐照石英玻璃实验提供依据. 相似文献
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为对空中飞行目标实施合理有效的强激光干扰,需要综合考虑采用的干扰方式、干扰效果以及考虑光斑偏移对干扰效果的影响。以热传导理论为基础,建立了激光辐照下移动目标温度场模型,采用伽辽金法建立了有限元分析模型,采用了等效比热容的方法处理材料的相变过程;并以Ansys软件为仿真平台,对目标在高斯分布的强激光作用下的温度场和热应力进行了综合仿真分析。结果表明,光斑与目标辐照区域的相对偏移对目标表面温度影响较大,对目标纵深破坏效应相对较小,应力变化主要发生在激光辐照区域,应力最大处也会随热源的移动而变化。 相似文献
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在综合考虑热源模型、对流辐射换热、相变潜热、材料非线性因素对激光沉积修复温度场影响前提下,建立了激光沉积修复的数学模型,采用有限元参数化设计语言(APDL)对多道多层激光沉积修复温度场进行了数值模拟。研究了激光沉积修复瞬时温度场及其中心高度上节点温度随时间变化情况,分析了修复件中心高度上温度梯度分布情况。搭建了激光沉积修复温度测量系统,对修复时表面温度进行了测量,并与模拟温度进行了比较,两者吻合较好。为控制激光沉积修复组织、提高修复质量提供有效手段。 相似文献
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采用1.06 μm单脉冲激光在不同能量密度下辐照特殊光电系统中典型薄膜光学元件,理论分析了激光辐照薄膜元件产生的温度场和热应力场,在此基础上建立了激光辐照多层薄膜的物理模型,计算软件使用ANSYS软件的热分析模块对激光辐照薄膜元件产生的温度场和热应力场进行了模拟,分别给出不同激光能量密度下薄膜表面光斑中心的温度场、径向温度场和轴向温度场分布;同时给出不同能量密度下薄膜的轴向、径向和环向热应力分布。并对激光辐照薄膜元件产生的温度场、热应力场进行了分析,阐明了原因。 相似文献
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Jijun Wang Zhonghua Shen Baiqiang Xu Xiaowu Ni Jianfei Guan Jian Lu 《Optics & Laser Technology》2007,39(4):806-813
The use of a pulsed laser for the generation of the elastic waves in non-metallic materials in the thermoelastic regime is investigated by using finite element method (FEM), taking into account not only thermal diffusion and the finite spatial and temporal shape of the laser pulse, but also optical penetration and the temperature dependence of material properties. The optimum finite element model is established based on analysis of two important parameters, meshing size and time step, and the stability of solution. Temperature distributions and temperature gradient fields in non-metallic material for different time steps are obtained, this temperature field is equivalent to a bulk force source to generate ultrasonic wave. The laser-generated ultrasound waveforms at the epicenter and surface acoustic waveforms (SAWs) are obtained and the influence of optical penetration into the material on the temperature field and the ultrasound waveforms are analyzed. The numerical results indicate that the heat penetration into non-metallic material is caused mainly by the optical penetration, and the ultrasound waveforms, especially the shape of the precursor, are strongly dependent on the optical penetration depth into non-metallic material. 相似文献
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In the last years, hyperthermia induced by the heating of magnetic nanoparticles (MNPs) in an alternating magnetic field received considerable attention in cancer therapy. The thermal effects could be automatically controlled by using MNPs with selective magnetic absorption properties. In this paper, we analyze the temperature field determined by the heating of MNPs, injected in a malignant tissue, subjected to an alternating magnetic field. The main parameters which have a strong influence on temperature field are analyzed. The temperature evolution within healthy and tumor tissues are analyzed by finite element method (FEM) simulations in a thermo-fluid model. The cooling effect produced by blood flow in blood vessels from the tumor is considered. A thermal analysis is conducted under different distributions of MNP injection sites. The interdependence between the optimum dose of the nanoparticles and various types of tumors is investigated in order to understand their thermal effect on hyperthermia therapy. The control of the temperature field in the tumor and healthy tissues is an important step in the healing treatment. 相似文献
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Laser forming of a metal plate involves a complex thermoplastic process. To accurately control the deformation of a metal plate, its temperature distribution must be obtained first. In this paper, three-dimensional finite element method simulations of the temperature field that account for the temperature dependence of the thermal properties of the materials were carried out. By defining a dimensionless temperature T* and a special Y-coordinate Y*, we found that temperature distributions in the Y′ direction are similar for different thicknesses. An analytical model of the temperature of the high-temperature zone in the Y′ direction is derived for the first time based on the similarity of temperature distributions and data obtained from regression analysis. The comparison of analytical and numerical results shows good agreement with respect to temperature distributions. This investigation is of significance for the prediction of a deformation field in future works. 相似文献
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A numerical model is established to investigate the influence of transparent coating thickness on the laser-generated thermoelastic force source and ultrasound waves in the coating-substrate system by using the finite element method (FEM). Taking into account the effects of thermal diffusion, the finite width and duration of the laser source, as well as the temperature dependence of material properties, the transient temperature distributions are obtained firstly. Applying this temperature field to structure analyses as thermal loading, the thermoelastic stress field and laser-generated ultrasound wave in the specimen are obtained. The generation and propagation of the laser thermoelastically induced stress field and ultrasonic waves in coating-substrate system are presented in detail. The influence of transparent coating thickness on the transient temperature distribution, thermoelastic force source and the laser-generated ultrasound waveforms is investigated. The numerical results indicate that the thermoelastic force source and laser-generated ultrasound waveform are strongly affected by the coating thickness due to the constraint of coating. This method can provide insight into the generation and propagation of the laser-generated stress field in coating-substrate system consisting of a transparent coating and an opaque metallic substrate. It provides theoretical basics to optimize ultrasonic signal generation in particular applications and invert the physical and geometrical parameter of the coating-substrate system more accurately in the experiment. 相似文献
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栅极组件热变形是影响离子推力器工作性能及工作寿命的主要因素,为研究栅极组件升温过程中温度场分布及变化规律,探索能较准确模拟栅极温度场的方法,建立了栅极组件1/12全尺寸有限元模型进行温度场仿真计算。同时,基于实验室搭建的温度测量平台,测量了大气环境下加热时栅极组件的瞬态温度变化。对比有限元分析求解与试验过程中的温度场,加速栅平均误差为14.4%,屏栅平均误差为9.7%,双栅最大误差不超过18.4%,验证了有限元模型及方法的可信度和合理性。 相似文献