Effect of Extensometer Usage on Obtaining the Force-Displacement Curve of the Adhesively Single Lap Joint

Abstract

Structural adhesively bonded joints are frequently used in many areas spearheaded by the industries such as automotive, marine space, and aviation due to the great advantages they provide. Besides, load capacities of adhesively bonded joints which have different geometries, are generally determined experimentally. Being compatible of experimental and numerical analysis of adhesively bonded joints in the means of both load carrying capacity and displacement has a great importance. But, one of the most common problems in comparison of experimental and numerical analyses is in spite of the coherence of experimental and numerical analyses in load carrying capacity, it is observed that in the means of the displacement analysis, there is incompatibility between those analyses. In the present study, force-displacement curves of the single-lap cohesively bonded joints are obtained experimentally by using both strokes of two different tensile test machines which have identical calibrated load cells and video extensometer. Experimentally obtained result was compared with numerical analysis. In the experiments, AA2024-T3 aluminium and two-component Araldite 2015 were used as adherend and adhesive, respectively. As a result, there is considerable difference between the force-displacement curves of the single-lap overlap joints which obtained experimentally from stroke and video extensometer. Also, being new or old of the tensile test machines which have identical calibrated load cells varies the displacement curve of the joint. When the experimental data were compared with the results of the numerical analysis, it is concluded that, obtaining the force-displacement curves of joints by using video extensometer is more accurate.