基于多点模的板材柔性夹钳拉形夹持力

Clamping force of sheet metal flexible grippers stretch forming based on multi-point die

简单介绍了板材柔性夹钳拉形(FGSF)工艺,提出了其夹持力的理论模型和计算方法。建立了有限元模型,采用动态显式算法对不同材料、不同板厚的圆柱面、球形面及马鞍面的基于多点模的FGSF过程进行了数值模拟,分析了夹持力的变化及影响因素。模拟结果表明:材料和板厚对工件拉形时夹持力的影响非常敏感,较硬、较厚的板材拉形时需要较大的夹持力;双曲率工件成形时所需的夹持力明显大于单曲率工件。本文研究结果对板材柔性夹钳拉形装置的结构优化设计与实际板材拉形工艺的研究都有重要的参考价值。

The technology of sheet metal flexible grippers stretch forming （FGSF） was introduced briefly, theoretic formula and calculation method of clamping force were given. A finite element model was established, and the numerical simulations of FGSF based on multi-point die were performed by a dynamic explicit algorithm for the cylindrical, spherical and saddle surface of different material with different thickness. The variation histories of the clamping force and its influencing factors were analyzed. The results indicate that the material and sheet metal thickness are very sensitive to the clamping force during sheet stretch forming, and the relatively large clamping force is needed if material is stiffer and sheet metal is thicker. The clamping force for forming work-piece of double curvature is obviously larger than that for forming work-piece of single curvature. The obtained results are significant for the optimal design of sheet metal FGSF equipments and the study of sheet metal practical forming process.