非规则曲面件的多夹钳式柔性拉伸成形研究

应用多夹钳式拉形机具有高柔性化的特点，根据目标件确定毛坯形状，夹钳依据毛坯形状对其进行夹持，尝试柔性拉形中的非矩形毛坯夹持。针对某一非规则曲面件，分别建立矩形毛坯和梯形毛坯的拉形有限元模型，并进行拉形数值模拟，对比分析两种形状毛坯对成形结果的影响。模拟结果表明，梯形毛坯拉形件比矩形毛坯拉形件的应力、应变数值减小且分布均匀；减薄率更小。梯形毛坯更能够节省材料，提高材料利用率。在多夹钳式拉形机上对矩形毛坯和梯形毛坯进行拉形试验，验证模拟结果的正确性。通过数值模拟和拉形试验充分证明了多夹钳式拉形机能够对非矩形毛坯件夹持的可行性，拉形效果更好，可以为其他非规则曲面件拉形提供参考和借鉴，使拉形工艺在工业应用的领域得到进一步拓展，为新型拉形机的设计与开发奠定了基础。

Research of Multi-gripper Flexible Stretch Forming for Irregular Part

Applying highly flexible characteristics of multi-gripper stretch forming machine, the determination of blank shape is based on the target part, according to blank shape grippers clamped, the non-rectangular blank clamping is tested. The finite element models of rectangular blank and trapezoidal blank are built for irregular part, the stretch forming process is simulated, the forming results of two blank are analyzed comparatively. The simulation results show that the stress and strain of trapezoidal blank part is smaller and uniformly distributed; thinning value is smaller than that of rectangular blank part. Stretch forming parts of trapezoidal blank can save materials and improve the utilization of materials. Stretch forming experiments of rectangular blank part and trapezoidal blank part are conducted with multi-gripper stretch forming machine, the simulated results are validated. It has been fully proved that the non-rectangular blank clamping is feasible and the effect of stretch forming is better by numerical simulation and stretch forming experiments, can offer reference and study on stretch forming process of other irregular parts, stretch forming process is expanded in industrial applications, which has laid the foundation for the design and development of new stretch forming machine.