Study of mechanical behavior by fatigue of a cracked plate repaired by different composite patches

This research is based on the study of the fatigue behavior of an aluminum alloy plate with a central crack. The plate is subjected to a tensile loading on its lower and upper parts. Several parameters were highlighted, such as the loading effect with a load ratio R = 0. The effects of the load ratio on both the repaired and not repaired plates, by two composite patches, which are boron/epoxy and graphite/epoxy, were investigated, as well as the effect of the plate material on plate life, comparing different material

Innovative geometric design improves the resistance of simple metal / metal lap joint

Bonded assemblies are widely used in many industrial sectors mainly in the aerospace field. Many researches in these domains are focused on evaluating the stresses in the adhesive layer in order to achieve maximum strength and long service life. Factors that affect joint design are the mechanical and physical properties of the adhesive and the substrate. The reduction of stress concentration at the edges of the adhesive provides the strength of the adhesive layer. Our work fits in this context, based on the ASTM D1002 standard. The innovative idea of this paper is to bring geometric improvements to an assembly system type Aluminum/Aluminum 2024-T3 bonded with an adhesive ADEKIT A-140. The analysis of the stress distribution is performed by the three-dimensional finite element method using the ABAQUS calculation code. The geometric improvements presented in this work are beneficial and the results show a good reduction of the stress concentration along overlap length