SBIR-STTR Award

The proposed research addresses development of the 3-D boundary element methods (BEM) for bolted/bonded composite joints with discrete cracks. It aims at establishing novel, efficient, and highly accurate methodologies to predict stress and strain distributions in cracked composite joints with 3-D BEM. The proposed work combines both analytical and computational approaches. Analytical studies on the BEM (2-D and 3-D) will be directed towards (a) developing Green's functions for layered composites with dislocations; (b) developing Green's functions for delamination cracks and interacting cracks within the layers; (c) developing Green's functions for the layered composites with geometric discontinuities. Computational studies will then focus on (a) developing very efficient and accurate algorithms to calculate the 3-D Green's functions in cracked composite joints; (b) formulating a nonlinear analysis to the contact problems between deformable bolts and bolted boundary. Results from the analytical and computational developments will be combined to leapfrog current technologies in stress and stature analyses of composite joints.

Keywords:
BOUNDARY ELEMENT METHOD COMPOSITE JOINTS GREEN'S FUNCTION THREE-DIMENSIONAL CRACK

The proposed research addresses development of the 3-D boundary element methods (BEM) for bolted/bonded composite joints with discrete cracks. It aims at establishing novel, efficient, and highly accurate methodologies to predict stress and strain distribuation in cracked composite joints with 3-D BEM in a user-friendly Window enironment. The proposed work combiens both analytical and computational approaches. Analytical studies on the BEM (2-D and 3-D) will be directed towards (a) developing Green's functions for layered composites with dislocations; (b)developing Green's functions with point forces and dilocations for delamination cracks and interacting cracks within the layers; (c) developing Green's functions for the layered composites with geometric discontinuties. Computational Studies will then focus on (a) developing very efficient and accurate algorithms to calculate the 3-D Green's functions in cracked composite joints' (b) formulating a nonlinear analysis to the contact problems betwen deformable bolts an bolted boundary; (c) developing a symmetric BEM formulation. Results fro the analytical and computational developments will be combined to leapfrog current technologies in stress and fracture analyses of composite joints.