Study Of The Mechanical Characteristics Of Holed Plates With Bonded Composite Patches

In the engineering application, thin plate structure would easily be cracked and perforated. In order to keep the integrality of the whole structure, repairing upon the damaged parts is always needed. Composite materials bonded repairing is a new kind of repairing technology, which does well in thin plate's repairing. In this paper, the repairing technique and the mechanical properties of center-holed aluminum and composite plates with bonded composite patches are analyzed systematically by finite element method and tested experimentally. The main work is summarized as follows:[1] The plane analytical model is established for static analysis of repaired thin pate. According to the mechanical characteristics of repaired plate with patches, the repaired plate is simplified to a plane model, which is under the co-action of the extension in the plane, the transverse load and the shear force out of the plane. And the equilibrium equations, the strain-displacement relations and the constitutive relations are derived. Moreover, the cross-section shear stress of the plate is studied.[2] Composite patches and samples are made and the mechanical properties are tested. After that, the pretreatment of the repairing surfaces and the process of bonded repairing are discussed. For the aluminum plates, mechanical cleaning will be introduced firstly, and then acid poultice made by experiment will be used. And for the carbon fiber composite plates, the techniques of removing grease will be employed.[3] The degree of the damage of the centered-holed aluminum and composite plates and the extent of furbishing after repairing are analyzed. And the correlations between the hole size and the whole stiffness of the structure, the stress concentration coefficient and the properties of remained intensity is tested. Furbishing effects of double-sided repair and single-sided repair are compared with each other. The influences to repairing effect of patch length, thickness and layout style are investigated. And the analytical results are validated by experiment dates.