脉动液压加载条件下薄壁金属管成形规律

Forming laws of thin-walled metal tube under pulsating hydraulic loading

以薄壁金属管液压成形工艺为研究对象,基于SS304不锈钢薄壁管在脉动及非脉动液压成形试验中的变形数据,对比分析了两种加载条件下薄壁金属管的轴向壁厚分布、最大减薄率、轴向轮廓形状、最大胀形高度及应变变化规律等,来反映脉动液压加载条件下薄壁金属管的成形性能,分析脉动加载参数(脉动频率及振幅)对金属管成形性能的影响。结果表明,液压加载方式对薄壁金属管的变形规律有重要影响,合理的液压加载方式有利于提高材料的成形性能。与非脉动液压加载条件相比,脉动液压成形时金属材料更容易进入成形区域,脉动液压加载条件下薄壁金属管的壁厚更小、周向和轴向变形量更大、分布更均匀。当脉动频率和振幅合理组合时,薄壁金属管可以获得最好的成形性能。

Taking the hydroforming process of thin-walled metal tubes as the research object,based on the deformation data of SS304 stainless steel thin-walled tubes in pulsating and non-pulsating hydroforming experiments,the axial wall thickness distribution,the maximum thinning rate,the axial profile shape,the maximum bulging height and the strain variation of the thin-walled metal tubes under the two loading conditions were compared and analyzed to reflect the forming performance of the thin-wall metal tubes under pulsating hydraulic loading,and analyze the effects of pulsating loading parameters(pulsating frequency and amplitude)on the forming performance of metal tubes.The results show that the hydraulic loading mode has significant effect on the deformation laws of thin-walled metal tubes,and the reasonable hydraulic loading mode is beneficial to improve the forming performance of the material.Compared with the non-pulsating hydraulic loading condition,the pulsating hydraulic forming is easier for the metal material to enter the forming area,the wall thickness of thin-wall metal tube is smaller,the circumferential and axial deformation is larger,and the distribution is more uniform under the condition of pulsating hydraulic loading.When the pulsating frequency and amplitude are reasonably combined,the thin-walled metal tubes can obtain the best forming performance.