The effects of size and stacking sequence of composite laminated patch on bonded repair for cracked hole

Abstract

The performance of a bonded repair for cracked holes has been studied using the three dimensional finite element method, linear elastic fracture mechanics and strain energy density theory. Increasing the composite patch size reduces the strain energy level at the crack tip; increasing the patch length normal to the crack is a better choice. The stacking sequences of the laminated patch have little influence on the strain energy distribution in the vicinity of the crack. To repair the cracked holes of aircraft components subjected to variable direction loading during flight, the orientations of the patch ply, 90 ~ and 4-45 ~ with respect to the crack direction, are the optimum selection in bonded repairs.

Effect of Interface Structure on Mechanical Properties of Advanced Composite Materials

“…It is shown that the stress intensity factor K estimated using the Rose model provides a reasonably good connection with observed d a /d N , where a is the crack length and N is the cycle of fatigue loading. Many numerical analysis techniques, such as finite element method (FEM) [ 67 – 81 ], boundary element method (BEM) [ 82 – 84 ], and finite element alternating method (FEAM) [ 85 , 86 ], have been proposed to the stress analysis of repaired structures. Atluri, Chow and Wang [ 87 ] applied the FEAM to model composites bonded to metals.…”