Joining by Die-Less Hydroforming of Profiles with Oval Cross Section
Joining by Die-Less Hydroforming of Profiles with Oval Cross Section
复制标题
椭圆形截面型材的无模液压成形连接
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Tekkaya
中科院分区：
文献类型：
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作者：
Michael Müller;S. Gies;A. Tekkaya
无模液压成形连接用于通过液压膨胀产生搭接接头。由于两个接合伙伴的弹性恢复的差异，干涉压力p保持在它们的接触区域处。由于可以在不依赖热量的情况下生产多材料接头，该工艺在轻量化应用中具有很大的连接潜力。因此，工艺极限被扩展，以便可以连接具有非旋转对称横截面的型材。为此，开发了一种用于椭圆截面型材的新工具。内、外连接件分别由铝6060和铝6082制成。通过数值模拟和实验验证了搭接长度和外连接件不同壁厚的影响。观察到干扰压力的上限，这也是以前发现的圆形横截面的轮廓。流体压力极限与分析计算值的配置与圆管在等效条件下进行了比较。分析模型低估了压力极限。与圆管相比，椭圆截面型材的应变分布是不均匀的，这导致了弯曲应力的叠加。此外，内部和外部连接伙伴的刚度差异导致压力依赖于接触面积，该接触面积在分析模型中被假定为常数。
Joining by die-less hydroforming is used to produce overlap joints by means of hydraulic expansion. Due to a difference in the elastic recovery of the two joining partners an interference pressure p remains at their contact area. Due to the possibility to produce multi-material joints without relying on heat, the process has great potential for joining parts in lightweight applications. Therefore, the process limits were extended so that profiles with non-rotationally symmetric cross-sections can be joined. For this purpose a new tool for profiles with oval cross-section was developed. The inner and the outer joining partner ware made of aluminum 6060 and aluminum 6082 respectively. The influence of the overlap length and different wall thicknesses of the outer joining partner were investigated by numerical simulations and validated by experiments. An upper limit in interference pressure was observed which was also found previously for profiles with circular cross sections. The fluid pressure limit is compared with the analytically calculated value for a configuration with circular tubes under equivalent conditions. The analytical model underestimated the pressure limit. In contrast to circular tubes, the strain distribution of profiles with oval cross sectional shapes is not uniform, which results in superposed bending stresses. Also a difference in stiffness of the inner and outer joining partner leads to a pressure depended contact area which is assumed constant in the analytical model.