| dc.description.abstract | Woven composite tows can be approximated by creating surfaces using the Virtual Textile Morphology Suite (VTMS) developed at the Air Force Research Lab (AFRL). These surfaces have interpenetrations between tow surface meshes which must be resolved in order to have strict, compatible mesh between all domains. A compatible mesh is desirable to reduce the complexity of the model and allow for a wider range of FEA tools to be used for analysis. To detect these interpenetrations, the surfaces were approximated using Non-Uniform Rational B-Spline (NURBS) surfaces with the SISL library from SINTEF. The interpenetration regions were then identified by B-Spline curves which, when included during the mesh generation process, allowed the surface interpenetrations to be removed and replaced with a compatible mesh between tows. The meshes are strictly tied together to investigate the effects of removing the thin slices of matrix from between tows in close proximity. These resulting meshes were subjected to a simple in-plane loading and compared to another method for removing interpenetrations that shrinks the tow cross-sections until they no longer penetrate. The predicted stresses show that the new method can create small regions of high magnitude stress in the tow local to the edge of the connected region between tows, and that high mesh refinement around these regions can increase the magnitude of these stress concentrations. In regions away from the boundary of the connected regions, both models predict similar stress responses. Also, the analysis predicts less matrix volume at high von Mises stress due to the lack of matrix between tows in the NURBS method meshes. While the analysis shows evidence of singularities, the size of the concentrations and the similar overall response as the previous method show that the new method has some merit, particularly when considering the potential use cases for compatible, connected regions between tow meshes. | |
