Köhler Daniel, Kupfer Robert, Troschitz Juliane, Gude Maik
Institute of Lightweight Engineering and Polymer Technology (ILK), Technische Universität Dresden, 01069 Dresden, Germany.
Materials (Basel). 2021 Apr 9;14(8):1859. doi: 10.3390/ma14081859.
As lightweight design gains more and more attention, time and cost-efficient joining methods such as clinching are becoming more popular. A clinch point's quality is usually determined by ex situ destructive analyses such as microsectioning. However, these methods do not yield the detection of phenomena occurring during loading such as elastic deformations and cracks that close after unloading. Alternatively, in situ computed tomography (in situ CT) can be used to investigate the loading process of clinch points. In this paper, a method for in situ CT analysis of a single-lap shear test with clinched metal sheets is presented at the example of a clinched joint with two 2 mm thick aluminum sheets. Furthermore, the potential of this method to validate numerical simulations is shown. Since the sheets' surfaces are locally in contact with each other, the interface between both aluminum sheets and therefore the exact contour of the joining partners is difficult to identify in CT analyses. To compensate for this, the application of copper varnish between the sheets is investigated. The best in situ CT results are achieved with both sheets treated. It showed that with this treatment, in situ CT is suitable to properly observe the three-dimensional deformation behavior and to identify the failure modes.
随着轻量化设计越来越受到关注，诸如压铆之类的省时且经济高效的连接方法正变得越来越流行。压铆点的质量通常通过诸如金相切片等非原位破坏性分析来确定。然而，这些方法无法检测加载过程中出现的现象，如弹性变形和卸载后闭合的裂纹。另外，原位计算机断层扫描（原位CT）可用于研究压铆点的加载过程。本文以两个2毫米厚铝板的压铆连接为例，介绍了一种对压铆金属板单搭接剪切试验进行原位CT分析的方法。此外，还展示了该方法在验证数值模拟方面的潜力。由于板材表面局部相互接触，在CT分析中，两块铝板之间的界面以及连接部件的精确轮廓很难识别。为弥补这一不足，研究了在板材之间涂抹铜漆的方法。对两块板材都进行处理可获得最佳的原位CT结果。结果表明，通过这种处理，原位CT适合于恰当地观察三维变形行为并识别失效模式。
