Shear cutting and counter shear cutting of sandwich materials
Shear cutting and counter shear cutting of sandwich materials
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DOI：
10.1016/j.jmapro.2013.03.001
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发表时间：
2013-08
影响因子：
6.2
通讯作者：
M. Liewald;C. Bolay;S. Thullner
中科院分区：
文献类型：
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作者：
M. Liewald;C. Bolay;S. Thullner
新型轻质夹层材料挑战了现有的成型工艺以及后续工艺步骤。因此，必须评估剪切的制造潜力。对两种切割方法进行了比较。常用的方法是一冲程内的剪切切割，另一种称为反剪切切割，它使用两冲程。切割夹层材料的挑战是不同层内孔径的变化、纺织品的磨损、孔轮廓的变形以及毛刺的形成。这些效应发生在传统剪切切割中，因为中间层和下金属板是由上金属板的废料而不是切割冲头切割的。以下方法包括使用闭合切削刃进行剪切，即在五种不同的夹层材料中切孔。三明治示例性地代表了多种可能的材料设计。例如，已经使用了铝和钢面板、不同厚度的中间层以及不同的中间层材料（例如集成纺织纤维）。已经确定了适当的切削参数，例如模具间隙和压边圈的使用。为了获得良好的结果，具有良好引导和精确控制冲头位置的刚性机器设计至关重要。对传统剪切切割的观察表明，需要 4% 的小切割间隙。由于下面板的叠加力，上面板可以实现高抛光区域。主要结论表明，三明治材料的高切割质量需要反向剪切切割。因此，面向中间层的下片材的翻转、下片材的抛光区域、纤维的良好切割质量显着改善，并且完全避免了毛刺形成。总结本文基于实验工作提供了夹层材料的切割参数。
New lightweight sandwich materials challenge existing forming processes as well as following process steps. As such the manufacturing potential of shear cutting has to be evaluated. Two cutting methods are compared. Method commonly used is shear-cutting within one stroke engaged, the other one is known as counter-shear cutting, which uses two strokes. The challenges of cutting sandwich materials are variation of hole diameter within the different layers, fraying of the textiles, deformation of the hole contour and burr formation. These effects occur in conventional shear cutting as the intermediate layer and the lower sheet metal are cut by the scrap of the upper sheet instead of the cutting punch. The following methodology included shear cutting with closed cutting edge i.e. cutting of holes into five different sandwich materials. The sandwiches exemplarily represent multiple kinds of possible material designs. For instance, aluminum and steel face sheets, different thicknesses of intermediate layers and different intermediate layers materials such as integrated textile fibers have been used. Adequate cutting parameters such as die clearance and the use of a blank holder have been determined. To achieve good results a stiff machine design with good guidance and precise control of punch position was crucial. Observations of conventional shear cutting revealed the need of small cutting clearance of 4%. High burnish area is possible for the upper face sheet due to the superimposed force by the lower face sheet. The major conclusion depicted that high cutting quality of sandwich materials requires counter shear cutting. Hence, the roll-over of the lower sheet facing the intermediate layer, the burnish area at the lower sheet, good cutting quality of the fibers improve significantly and burr formation is avoided completely. Summarized this paper provides cutting parameters for sandwich materials based on experimental work.