Adaptive Multi-Point Test Methodology and Numerical Modeling Approach for Enhancing Damage-Tolerant Composite Structures
Abstract
The effect of inherent manufacturing defects, in-service damage, and the presence of fastener holes on the post-buckling behavior of stiffened composite structures will be considered in this proposed study to expand the design space and develop novel damage-tolerant advanced structural concepts. The traditional three-point bending test will be extended to an adaptive, multi-point test method by changing the number, position, direction of support, and loading points. This will enable the investigation of skin-stiffener separation with various loading conditions, while observing the interaction of different post-buckling modes with manufacturing defects, impact damage, and fastener holes. The progressive failure under static and fatigue loading will be considered to understand the structural behavior of an aircraft structure under service conditions. An advanced finite element model based on a global/local analysis approach will be developed to supplement the experimental test setup and expand the structural design space. A fundamental study will be conducted to develop a detailed numerical model to capture the interactions between the postbuckling modes and the presence of defects, damage, or fastener holes of a multi-stringer panel. There are several on-going efforts by Air Force and NASA to reduce the weight, part count, logistic footprint, and maintenance downtime of aircraft with composite structures. Unitized composite structures provide outstanding performance improvements in all these categories. Fundamental understanding of the stiffened composite structural behavior under service conditions is necessary to advance the state of the art and develop novel damage-tolerant structural concepts. The proposed testing methodology coupled with a detailed finite element analysis will provide an approach for the structural community to design and test advanced structural concepts for future aircraft.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 28, 2017
- Source ID
- FA95501710305
Entities
People
- Chiara Bisagni
Organizations
- Air Force Office of Scientific Research
- Delft University of Technology
- United States Air Force