板料数控渐进成形过程中的热力学行为分析

Analysis of Thermodynamic Behavior of Sheet Metal in Numerical Control Incremental Forming Process

针对板料数控渐进成形过程中坯料温度升高的现象,在分析其热量来源的基础上,借助Abaqus有限元模拟软件探讨了成形工具与坯料之间的热力学行为。结果表明:在成形工具的作用下坯料逐次产生塑性变形,已成形区的等效应力、应变分布较为均匀;坯料成形过程中最大等效塑性应变值不是出现在成形工具与坯料相接触的区域而是出现在已成形区;在摩擦生热和塑性变形功的共同作用下,成形工具与坯料接触区域的坯料温度急剧升高,变形抗力降低、塑性增加。成形工具与坯料界面间高速相对运动所产生的热量对坯料的局部加热是数控渐进成形技术提高板料成形性能的原因之一。

Aiming at the phenomenon of the blank temperature increasing in the process of NC incremental forming of sheet metal,on the basis of the analysis of the heat source,the thermodynamic behavior between the forming tool and the blank was discussed by means of Abaqus finite element simulation software.The results show that under the action of the forming tool,the plastic deformation of the blank is produced,the equivalent stress and the strain distribution of the formed region are relatively uniform,but there is insufficient plastic deformation phenomenon in some areas.The maximum equivalent plastic strain value in the blank forming process is not in the area where tile forming tool is in contact with the blank,but in the formed region.Under the joint action of friction heat and plastic deformation work,the temperature of the blank is rising sharply,the deformation resistance is reduced,and the plasticity is increased in the contact area of the forming tool and the blank.The local heating of the billet produced by the high speed relative motion between the forming tool and the blank interface is one of the reasons for improving sheet metal forming performance by NC incremental forming technology.