激光与光电子学进展, 2019, 56 (5): 051404, 网络出版: 2019-07-31
基于热力耦合的激光熔覆数值模拟与实验研究 下载: 1606次
Numerical Simulation and Experimental Research of Laser Cladding Based on Thermo-Mechanical Coupling
激光技术 激光熔覆 有限元模拟 生死单元 温度场 应力场 laser technique laser cladding finite element simulation birth-death element temperature field stress field
摘要
基于热-结构间接耦合非线性有限元分析,在不同的激光工艺参数下,利用ANSYS生死单元技术对激光熔覆的温度场和应力场进行了数值模拟,研究了激光功率和扫描速度对温度场和应力场分布规律的影响。结果表明,通过分析有限元模型的温度分布规律和试件金相组织的形貌特征,验证了该模型的可靠性;熔覆层温度变化分为脉冲式急速上升和呈双曲线形状下降两个阶段;沿激光扫描方向,熔覆层表面多个节点的温度-时间曲线具有逐渐增大的峰值;熔覆层与基体结合面中部沿Z 轴方向,靠近固定端应力较大,基底中部沿X 轴方向应力呈W状对称分布,自由端中部沿Y 轴方向,熔覆层和基体结合处易产生应力集中和突变。
Abstract
The temperature and stress fields of the laser cladding are numerically simulated by ANSYS birth-death element technique based on the thermo-mechanical indirect coupling nonlinear finite element analysis. The results show that this proposed model is reliable by analyzing the temperature distribution of the finite element model and the morphological characteristics of the metallographic structure of the experimental specimens. The temperature change of the cladding layer can be divided into two stages. In the first stage, the temperature rises rapidly like a pulse. In the second stage, the temperature drops to the overall temperature of the matrix which likes a hyperbolic shape. On the surface of the cladding layer and along the laser scanning direction, the peaks of the temperature time curves of multiple nodes show a trend of gradual increase. The distribution curves of the residual stress show that there is a greater residual stress at the position near the fixed end along the Z axis in the middle of the bonding surface of the cladding layer and the matrix. The residual stress is distributed symmetrically like the shape of W along the X axis in the middle of the matrix undersurface which is likely to cause stress concentration and mutation at the interface between the cladding layer and the matrix along the Y axis in the middle of the free end.
任仲贺, 武美萍, 唐又红, 韩基泰, 龚玉玲. 基于热力耦合的激光熔覆数值模拟与实验研究[J]. 激光与光电子学进展, 2019, 56(5): 051404. Zhonghe Ren, Meiping Wu, Youhong Tang, Jitai Han, Yuling Gong. Numerical Simulation and Experimental Research of Laser Cladding Based on Thermo-Mechanical Coupling[J]. Laser & Optoelectronics Progress, 2019, 56(5): 051404.