Q345中厚板V形折弯应力应变分析

Stress and Strain Analysis of Q345 Plate V- Shaped Bending

目的研究Q345中厚板在V形折弯时的应力应变中性层内移规律。方法通过对中厚板135°折弯过程进行数值模拟,分析了板料在成形过程中的等效应力应变及其中性层内移现象,测得了应变中性层与几何中间层之间的距离变化。在此基础上,采用厚度为16 mm的Q345板料进行物理实验,并与模拟结果进行了对比分析。结果在成形过程中,等效应力应变中性层均产生了内移现象,且应力中性层的内移量明显大于应变中性层的内移量;成形结束之后,应变中性层与几何中间层的距离为3.3 mm;实验结果显示,应变中性层的内移量为3.1 mm左右,与模拟值较为一致。结论数值模拟方法可以为应力应变中性层计算提供指导。对于中厚板折弯,采用几何中间层展开求得的坯料尺寸并不准确。

Objective To investigate the internal shift law of the stress and strain in neutral layer of Q345 plate V-shaped bending. Methods By simulating the 135° bending process of the plate,equivalent stress and equivalent strain as well as their internal shift phenomenon of the neutral layers were analyzed. Meanwhile,the distance between the strain neutral layer and the geometric neutral layer was measured. On this basis,the physical test was carried out using a Q345 sheet with a thickness of 16 mm,then the results were compared and analyzed with the simulation result. Results During the forming process,stress neutral layer as well as strain neutral layer both showed the internal shift phenomenon,and the displacement of the stress neutral layer was greater than that of the strain neutral layer. After forming,the distance between the strain neutral layer and the geometric middle layer was 3. 3 mm. The test result showed that the displacement of the strain neutral layer was about 3. 1 mm,which had a better agreement with the simulation result. Conclusion Numerical simulation could provide guidance for the calculation of the stress neutral layer and the strain neutral layer. For plate bending,the blank size obtained using expanded geometric middle layer was not accurate.