工艺参数对管材激光弯曲成形影响规律的研究

管材激光弯曲成形是一种柔性金属塑性成形方法。将连续的激光光斑简化为一间歇跳跃的方形匀强面热源,并考虑材料性能参数与温度的相关性,建立了管材激光弯曲成形的热-机耦合有限元工艺仿真模型,对成形过程进行了数值模拟。有限元模拟结果表明:在其他条件不变的情况下,激光弯曲角度随激光功率的增大而增大,两者基本上成线性关系;弯曲角度随扫描速度的升高而减小,随光斑直径的减小而增大,但当光斑直径减小到一定程度后,弯曲角度开始减小;弯曲角度随扫描包角的增大而增大,当扫描包角为180°时,弯曲角度达到最大,弯曲角度随扫描包角的继续增大而减小;扫描次数与弯曲角度间成近似的线性关系,且第一次扫描管材产生的弯曲角度最大。

Study on Influence of Process Parameters on Laser Tube Bending

Laser tube bending is a flexible metal forming process. A thermo-mechanical FEM model of the laser tube bending is established. The continuous laser spot is simplified as a square heat resource with an intermittent and jumping movement. The relativity between material properties and temperature is considered. Based on the FEM model, the process of laser tube bending is analyzed numerically. When the other parameters keep constant, the laser bending angle augments with increase of laser power. The laser bending angle decreases with increase of scanning velocity. Meanwhile, the bending angle diminishes with the diameter of laser spot. The angle begins to decrease when the diameter of the laser spot get to a critical value. The bending angle enlarges if the scanning wrap angle augments. The bending angle is largest when scanning wrap angle is 180.When scanning wrap angle is over 180 , the bending angle decreases with the increase of scanning wrap angle. The relation between the number of scans and the bending angle is close to linear one.The bending angle induced by the first scanning is largest.