Development and validation of a parametrical modeling and analysis tool for bolted repair in composite structures

Bolted repair is a preferable repair method in damaged composite structure, especially in battle damage repair. However, the repair design process is complex, and it is difficult to meet the need for rapid sizing. A parametrical modeling and analysis tool was developed for design of composite bolted repair with penetrating damage, using VB.NET combined with p-version finite element method. The tool allows the user to create the joint geometry through a menu-driven interface and then to generate a customized mesh. Boundary conditions, bolt pattern, bolt diameter, applied load and material properties could also be set. The model was solved automatically, and based on the analysis results, the load transfer ratio, bolt load and the stress around the critical hole are offered by the analysis tool. Finite fracture mechanics model is used to predict the failure load and failure mode of the repaired joints. A case study was shown to demonstrate the usefulness of the tool.