Effect of the Fibers Orientation of the Different Types of Composite Plates Notched of U-Shape Repaired by Composite Patch

Abstract

The main objective of this work is to repair a structure of composite materials by gluing composite patches with different fiber directions. The effects of stress distribution, damaged area ratio, stress intensity factor KIC and imposed stacking sequence were highlighted by a comprehensive study that contained two sides, an applied experimental side and a numerical model side. The composite materials plates studied in this work are 8-layer of graphite/epoxy, glass/epoxy and boron/epoxy, with different angles. The results obtained clearly show with respect to the experimental side that the orientation of the fibers affects the ultimate strength of failure and that the fibers oriented longitudinally in the direction of the tensile strength give us an ideal performance of the composite material. As for the model aspect of this study, the effects of stress intensity factor and the relationship between the damaged area and the fiber orientation on the performance of these patches were studied. We can conclude from this study that the orientation of the fibers has an important role in the performance of the composite material and its efficiency in repair.

Keywords:
Composite, ultimate strength ${\sigma }_u$, Stress intensity factor (SIF), the damaged area ratio (D_R), Von Mises Stress, laminate; Stacking sequence