The optimal analysis of patch bonding parameters in composite repairing technique

A "double-plate with spring" model and finite element computation have been employed in this paper for the analysis of adhesive bonding patch technique to repair through-thick damaged composite laminates and metal structural components. Some effects of patch geometrical parameters on repair efficiency have been investigated, such as patch diameter, its thickness, its layout and bonding thickness, etc. Several major conclusions have been drawn in this paper: (1) patch diameter has less important effect on strength recovering efficiency; (2) there exists reasonable relative patch thickness for repair effect, which is 50% thickness of damaged mother-plate for one-side layout of bonding patch, and 80% that for twin-side one; (3) the effect of bonding interface thickness on repair efficiency depends on the maximal shear stress inside of the interface; (4) the size of repaired components with the same damage and bonding geometry has some influence on repair efficiency; (5) the laws of patch parameter influence for damaged composite laminates are very similar to those for metallurgical structural components.