基于共轭梯度算法的激光加热物体表面温度的反演
发布时间：2018-07-29 14:03
【摘要】：近年来,随着激光技术的迅速发展,激光与材料相互作用这一研究领域引起研究者们深入地研究。而激光辐照材料产生的热效应,作为激光加工、热处理以及激光破坏效应的基础,更是吸引着越来越多学者的关注。本文首先通过激光辐照材料的热传导理论建立正演模型,并根据拉普拉斯变换计算材料温度场的解析解。然后选取了材料内部测量温度和计算温度数据的残差平方和作为目标函数,利用共轭梯度算法对目标函数的极小化求解,得到材料参数。最后分别选取激光辐照均匀材料、吸收率不变的双层系统材料和吸收率变化的双层系统材料三种情况,对材料参数进行了反演,根据得到的材料参数利用现有的正演方法计算材料表面温度。结果表明,此算法能有效的反演材料参数,进而计算材料表面的温升。并且具有收敛较快,反演精度较高的特点。本文对于研究激光损伤、激光加工过程中的温度反演和参数反演具有一定的参考作用。
[Abstract]:In recent years, with the rapid development of laser technology, the research field of laser-material interaction has been deeply studied. As the basis of laser processing, heat treatment and laser damage, the thermal effect of laser irradiated materials has attracted more and more scholars' attention. In this paper, the forward model is established by the heat conduction theory of laser irradiated materials, and the analytical solution of the material temperature field is calculated according to the Laplace transform. Then, the residual square sum of measured temperature and calculated temperature data is selected as the objective function, and the material parameters are obtained by using conjugate gradient algorithm to minimize the objective function. Finally, the parameters of the materials are inversed by three cases: homogeneous materials irradiated by laser, bilayer system materials with invariable absorptivity and bilayer system materials with varying absorptivity. According to the obtained material parameters, the surface temperature of the material is calculated by using the existing forward modeling method. The results show that the algorithm can effectively retrieve the material parameters and then calculate the temperature rise of the material surface. And it has the characteristics of fast convergence and high inversion accuracy. This paper is useful for the study of laser damage, temperature inversion and parameter inversion during laser processing.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249
本文编号：2152909
[Abstract]:In recent years, with the rapid development of laser technology, the research field of laser-material interaction has been deeply studied. As the basis of laser processing, heat treatment and laser damage, the thermal effect of laser irradiated materials has attracted more and more scholars' attention. In this paper, the forward model is established by the heat conduction theory of laser irradiated materials, and the analytical solution of the material temperature field is calculated according to the Laplace transform. Then, the residual square sum of measured temperature and calculated temperature data is selected as the objective function, and the material parameters are obtained by using conjugate gradient algorithm to minimize the objective function. Finally, the parameters of the materials are inversed by three cases: homogeneous materials irradiated by laser, bilayer system materials with invariable absorptivity and bilayer system materials with varying absorptivity. According to the obtained material parameters, the surface temperature of the material is calculated by using the existing forward modeling method. The results show that the algorithm can effectively retrieve the material parameters and then calculate the temperature rise of the material surface. And it has the characteristics of fast convergence and high inversion accuracy. This paper is useful for the study of laser damage, temperature inversion and parameter inversion during laser processing.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249
【参考文献】
相关期刊论文 前3条
1 尹益辉;王伟平;陈裕泽;;激光辐照下多层圆柱体中三维瞬态温度场的解析解[J];爆炸与冲击;2008年01期
2 叶圣麟;马军山;黄鑫;;激光切割脆性材料的温度场模拟[J];光学技术;2007年04期
3 赵元安,王涛,张东平,贺洪波,邵建达,范正修;脉冲激光辐照光学薄膜的缺陷损伤模型[J];光子学报;2005年09期
，本文编号：2152909
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