激光表面加热三维非线性强瞬态导热的数值模拟

The numerical simulation on 3-D non-linear intensive transient temperature field and thermal stress field during laser heating process has been carried out in this project. First,based on numerical solution of tranditional Fourier heat conduction law and intensive transient non-fourier heat conduction law, the criteron of transient effect has been established. It is thus confirmed that the non-Fourier transient analysis can more accurately reflect the intensive transient and thermal shock characteristic during laser heat treament of metalics, but the tranditional Fourier heat conduction law can be still used when the macro- temperature field are calculated. The criteron and this conclustion provided the theory basis for the following research work. Second, based on the interaction between temperature - phase transformation - stress/strain during laser heat treatment, the integrated mathematical model has been established for the coupled simulation between temperature field and stress field under laser heating. This numerical analysis method can consider multiple strong non-linear factors and complicated boundary conditions, and can accurately calculate the temperature field, microstrcture, stress and distortion. This work has layed a solid basis for establishement of numerical simulation on high energy beam surface modification and thermal process..Finally, the results thereinbefore have been applied in the laser phase transformation hardening process, and a series of conclusions have been obtained by the numerical simulation. Through the comparison between testing results and calculated results, the mathematical models have been furtherly modified and consummated. All these provided the theory basis for laser heating, high density energy treatment and other technology, and demonstrated a wide application foreground..

本项目拟研究激光加热过程三维非线性强瞬志温度场与热应力场的数值模拟，建立求解热冲击双曲线型偏微分议程的有限元、有限差分数值分析方法，实现温度场-相变-应力场耦合非傅立叶分析。通过实验测试分析与模拟结果的对比，进一步修正和完善数学模型。为激光加热、高能密度处理等工艺的发展提供理论依据，有广阔应用前景。.