目的：解决2A16铝合金锥形件常温充液成形困难、表面质量差的问题。方法介绍了充液热成形工艺，并提出了3种锥形件成形方案，通过专用有限元软件 Dynaform 对所有方案进行了数值仿真；同时，对一步成形方案进行了试验。结果通过试验验证了有限元模型的正确性。由仿真分析可知，成形缺陷包括悬空区起皱和凹模圆角及底部破裂，一步成形方案不可取，两步成形方案均可以将减薄率控制在13%以下。起皱危险主要发生在零件法兰以下30～55 mm 处。结论充液热成形与常温充液成形相比，可以显著提高材料的成形性；两步充液热成形方案可以获得2A16铝合金锥形件；预成形凸模的形状设计对零件的表面质量影响明显；最终确定用先热冲压筒形件，后充液热成形的工艺方案，来成形2A16铝合金锥形件。
To obtain the influence of fluid pressure and temperature on warm hydroforming of 5A06-O aluminum alloy sheet, the unified mechanics equilibrium equations, which take through- thickness normal stress and friction into account, were established in spherical coordinate system. The distribution of through-thickness normal stress in the thickness direction was determined. The relation between through-thickness normal stress and fluid pressure was also analyzed in different regions of cylindrical cup. Based on the method of subtracting one increasing function from another, the constitutive equation of 5A06-O applied to warm hydroforming was established and in a good agreement with uniaxial tensile data. Based on whether the thickness variation was taken into account, two mechanic models were established to do the comparative study. The results for the studied case show that the calculated stress values are pretty close according to the two models and consistent with results of finite element analysis; the thickness distribution in flange computed by the second model conforms to the experimental data. Finally, the influences of fluid pressure on the flange thickness and radial stress were analyzed.
