- 上一篇：激光的形成过程和模式的数值模拟
- 下一篇：随机粗糙表面激光后向散射特性的理论模拟
摘要长脉冲激光与金属材料相互作用中将出现一系列的热学和力学效应。本文针对长脉冲激光在铝板上打孔的过程进行了理论计算和有限元模拟。
首先讨论和总结了激光与靶材相互作用的物理机制，包括激光对靶材的加热，激光加热的应用，加热引起材料的升温，熔化，气化的过程，过程中的热传导方程和定解条件。然后，建立了长脉冲激光和铝板相互作用的物理模型，用有限元法模拟了打孔的过程，通过比较实验和数值结果验证了数值算法的合理性。67124
接下来从数值模拟的角度研究了长脉冲激光与铝板相互作用的物理现象，利用Comsol软件建立了长脉冲激光与铝板相互作用的二维物理模型，模拟研究了不同激光峰值能量和脉宽对靶材中心温度，打孔深度和打孔质量的影响。
本文的研究结果对了解长脉冲激光与物质相互作用的机理提供理论依据，所得结论对激光精细加工/激光武器的研究有一定的借鉴意义。
毕业论文关键词：长脉冲激光 金属 打孔 有限元
毕业设计说明书（论文）外文摘要
Title：Theoretical research of long pulse laser parameter impact on keyhole quality during laser drilling on Aluminum
Abstract:
Series of thermal and mechanical effect will occur during millisecond laser heating of metals. In this thesis,the perforation on aluminum panels by long wave-length pulse laser are investigated by theoretical calculation and finite element simulation.
In the first part,we discussed and concluded that the mechanism of interaction between laser and target which included the process of temperature rising,application of laser heating, melting and vaporization of target material by laser heating. in the process of heat conduction equation and the definite solution conditions.Besides,the physical model of perforation on aluminum panels by long wave-length pulse laser was built and different kinds of parameters’ affect on the process of formation of little holes were calculated and analyzed by finite element method. And the numerical algorithm is verified by comparing the experimental and the calculated results.
In the second part,the physical phenomenon of interaction between long wave-length pulse laser and metal was studied by numerical simulation using software Cosmol. In the simulation, I built up the 2-D model of interaction between laser and aluminum panel and studied various factors’ influence on target central temperature, perforation depth and perforation quality including laser peak energy and pulse width.
The result of this paper provided theoretical basis for interaction between millisecond laser and substance which has certain significance to refined laser machining and laser weapons.
Key word： millisecond laser,metal,keyhole formation,FEM
目 次
1 绪论6
1.1 研究背景和意义6
1.2 强激光对物质的加热，熔融和气化作用的研究现状7
1.2.1 国外研究状况7
1.2.2 国内研究状况9
1.3 激光与物质相互作用过程数值模拟研究的特点和问题10
1.4 本文的主要工作11
2 长脉冲激光打孔的理论模型12
2.1 激光加热12
2.1.1 热传导方程和定解条件12
2.1.2 激光加热的应用13
2.2 激光引起材料的熔化和气化14
2.3 物理模型的建立15
2.3.1 物理模型中的假设与控制方程15
2.3.2 边界条件和初始条件16
2.4 数值模拟结果与讨论20
2.5 本章小结22
3 激光参数对打孔过程的影响24
3.1 激光能量对打孔过程的影响24
3.1.1 激光能量对铝靶材中心温度的影响24