Tool for Analysis to Predict Strength and Durability of Curved and Tapered Composite Structures under Multiaxial Loading

Global Engineering and Materials, Inc. (GEM) along with its team members National Institute for Aviation Research (NIAR) at Wichita State University, the United States Naval Research Laboratory (NRL), and Sikorsky Aircraft (SAC) propose to build on the current success of the Composite Bolted and Bonded Analysis Toolkit for Abaqus (CB2ATA) tool for static strength and fatigue life prediction of curved and tapered composite rotorcraft flexbeams under multiaxial loading. The enhanced CB2ATA toolkit will include a multi-resolution and hybrid element modeling approach for accurate 3D stress prediction in the presence of ply drops and other fabrication defects such as voids and ply waviness. Through the coupling of the use of solid elements with user-defined material models at critical regions and continuum (solid) shell elements at non-critical regions, a high computational efficiency can be achieved via the sub-laminated aggregation and the use of tie interfaces of regions of distinct mesh densities. Discrete damage informed continuum damage models will be enhanced to capture damage progression under multiaxial loading. To demonstrate and validate our enhanced modeling approach for a representative flexbeam component, multiple specimens with ply drops will be fabricated and tested by NIAR under axial tension and mixed tension and bending.