柔性离散夹钳拉形工艺的数值模拟

介绍了柔性离散夹钳拉形机的特点,建立了柔性离散夹钳拉伸成形有限元模型。对球形面和鞍形面进行了数值分析,研究了拉形速度、摩擦因数和夹钳形状对成形结果的影响。数值模拟结果表明:在兼顾成形效率和精度的情况下,可选1m/s为拉形速度。润滑条件越好,成形件应力应变和厚度分布越均匀。与方形夹钳相比,圆形夹钳能有效改善过渡区和夹持区的流动状况,使应变更均匀,减薄量较小。通过实验验证了模拟的正确性,模拟结果对离散夹钳拉形机的优化设计以及实际板材拉形工艺具有指导价值。

Numerical simulation of flexible discrete clamp stretch forming process

The characters of flexible discrete clamp stretch forming(DCSF) machine were introduced.A FE model of flexible DCSF was built.Spherical surface and saddle surface were selected for simulation.The influences of stretching velocity,friction coefficient and clamp shape on the forming results were researched.The numerical simulation results showed that the stretching velocity 1 m/s is good for satisfactory forming efficiency and accuracy.The better the lubrication condition is,the more homogenous distributions the stress,strain and thickness are.The clamp shape is sensitive to liquidity of transitional area and clamping area,more uniform strain and smaller thinning value were got by circular clamp.The simulated results are validated by experiment.The obtained achievements are useful for the optimal design of DCSF machine and the practical stretch forming process implementation of sheet metal.