Simplified Analytical Procedure for Prediction of Fracture Damage in Composite Structures (MSC P1B16-203)

"A software package is needed that can efficiently model typical composite bonded and co-cured joints used in Naval ship construction. This package must be able to accurately compute the strain-energy-release-rate for user defined cracks. MaterialsSciences Corporation (MSC) has an existing code called SUBLAM that performs this operation using closed-form solutions of high-order plate assemblages. When plates are stacked, the interfacial tractions and displacements are computed exactly (within theassumptions of the plate theory). This approach leads to accurate interlaminar stresses and, therefore, accurate fracture calculations. The plates can be assembled in a manner similar to the finite element method, allowing one to model complex jointconfigurations. Many validation problems have shown the code to be highly accurate. For the Phase I SBIR, MSC will modify this code to more directly applicable to the structures of concern, and will demonstrate a graphical user interface. The userinterface will include predefined parametric models of typical joints. Similar aids will be created to interpret the output so that failure predictions, and failure interaction diagrams are automatically generated. Failure loads of joints for compositestructures are notoriously difficult to predict. This project will result in a user-friendly, efficient, and accurate software product that will enable engineers to rapidly assess typical joints. The