A new experimental approach for the estimation of bending moments in adhesively bonded single lap joints

The state of stresses in the adhesive layer may be described by a parameter known as edge moment factor. This parameter is also defined as normalized bending moment, or bending moment factor. The main goal of the present work is to determine the bending moment factor using the Digital Image Correlation method. For this purpose, 9 aluminum-epoxy single-lap-joint specimens with different adhesive thicknesses and ratios of segment of outer adherend length to the half of the overlap length were investigated. All specimens were tested under tensile loading. Deflections of single lap-joint specimens were estimated by the Digital Image Correlation method. In addition, Hart-Smith, Goland and Reissner and modified Goland and Reissner models were investigated in order to compare theoretical prediction with experimental data. The improvement to the Goland and Reissner model proposed by Tsai-Morton was more suitable to describe the mechanical behavior of investigated single-lap joints. Results show that the alternative methodology proposed here is a good way for estimating bending moment.