通过预成形降低内高压成形压力的机理分析

采用力学分析和有限元模拟对空心零件圆角部位在内高压成形过程中的应力分布和变形机理进行了分析,针对多边形截面空心件内高压成形,以矩形截面为例提出采用花瓣形预成形截面降低圆角成形压力的方法,分析了该方法降低圆角成形压力的机理,提出了花瓣形预成形截面形状关键参数计算公式,并通过试验进行了验证,为采用较低压力实现空心构件圆角内高压成形提供了理论指导.

Mechanism Analysis on Reducing Pressure of Tube Hydroforming through Preform

Pressure for tube hydroforming of lightweight parts is usually determined by the radii of bulgy corners because the pressure for forming a small corner is much higher than other positions.Therefore,it is a key problem how to reduce the pressure for forming the corner with a small radius in tube hydroforming.Stress distribution and deformation mechanism of the corner on a hollow component during hydroforming is analyzed by classical mechanics and finite element method.For tube hydroforming of hollow component with polygonal sections,a rectangular cross-section is regarded as an example and researched.A method to reduce the pressure through preforming a petal-like cross-section is presented and its mechanism is analyzed.A calculated equation of key parameters of the preforming contour is given and an experiment is carried out to verify the method.The theory is meaningful for hydroforming of tubular parts with bulgy small-radius corners under lower pressure.