Anasiewicz Kamil, Kuczmaszewski Józef
Department of Mechanical Engineering, Lublin University of Technology, 20-388 Lublin, Poland.
Materials (Basel). 2019 Nov 26;12(23):3911. doi: 10.3390/ma12233911.
The paper presents the results of nanoindentation testing, carried out along the thickness of the adhesive joint joining sheets of aluminum alloy. The purpose of the tests was to determine changes in the Young's modulus in the joint resulting from the active impact of the joined aluminum alloy sheets on the adhesive during curing of the adhesive bond. Structural changes that take place during curing of the joint, especially in the boundary zone, can have a significant impact on the adhesive properties and consequently, on the adhesive joint strength. The Young's modulus of the adhesive (Ek) in the joint assumes variable values as the distance from the connections changes. This phenomenon is called the apparent Young's modulus. The problem is to define the size of the boundary zone in which the value of Ek significantly differs from the value in the so-called core. Based on the obtained results of experimental tests, a numerical model was built taking into account the observed differences in the properties of the joint material. The stress distribution in the adhesive joint, single-lap connection with the three-zone adhesive joint, was analyzed in comparison to the classical numerical model in which adhesive in the adhesive joint is treated as isotropic in terms of rigidity.
本文介绍了沿铝合金薄板粘接接头厚度进行的纳米压痕测试结果。测试目的是确定在胶粘剂固化过程中，被连接的铝合金薄板对胶粘剂的主动冲击导致接头处杨氏模量的变化。接头固化过程中发生的结构变化，尤其是在边界区域，会对胶粘剂性能产生重大影响，进而影响粘接接头强度。接头中胶粘剂的杨氏模量（Ek）会随着与连接处距离的变化而呈现不同的值。这种现象称为表观杨氏模量。问题在于确定边界区域的大小，在该区域内Ek的值与所谓的“核心”区域的值有显著差异。基于实验测试获得的结果，建立了一个数值模型，该模型考虑了接头材料性能中观察到的差异。与经典数值模型相比，分析了具有三区粘接接头的单搭接连接中粘接接头的应力分布，在经典数值模型中，粘接接头中的胶粘剂在刚度方面被视为各向同性。
