On the Experimental Characterization of a 3D Multiaxial Fatigue Model for Structural Fiber Reinforced Composites
Abstract
A proposal is submitted for the purchase of a tension-torsion mechanical test frame (830E5 all electric tension-torsion test frame) and an advanced, high resolution thermal camera, the FLIR A6751. These instruments are to be used in the characterization and refinement of a novel multiaxial mechanistic fatigue model for textile composite structures that are earmarked for a multitude of Army applications, including Ground Maneuver and Air Systems, Cannon Tubes, Light-weight textile structures for vehicle power, and mobility and deployable force protection. In a current ARO project, [W911NF1920045], the PI and his team have developed a novel multiscale fatigue model motivated by the mechanisms by which fatigue damage and degradation of stiffness occur in textile polymer composites. It is known that, to a large extent, the degradation is governed by the cyclic response of the polymer matrix, specifically the stress-strain response of the matrix when subjected to fatigue loading, and the textile architecture, which includes details of the fiber tows and the textile weave and packing (consolidation during cure) pattern. A novel multiscale approach to model fatigue in textile composites based on the PIs past success on developing a multi-scale modeling framework for the quasi-static damage and failure modeling of textile composites is utilized. The mode is computationally efficient due to the utilization of a closed form solution for the sub-scale stress and strain states within the matrix captured via a reformulation of the composite cylinder model and referred to as the NCYL model. The NCYL model is coupled to a mesh-objective crack band model for capturing post-peak softening response in a discretization objective manner, and extended to model fatigue in textile composites. The proposed work utilizes the FLIR thermal camera for collecting experimental data on damage progression in-situ due to cyclic loading by conducting experiments using an advanced axial torsion test frame that is capable of supplying a multi-axial load state. With the new test frame it becomes possible to collect data that can examine the path dependency of the fatigure response. This is done by first cycling a specimen in axial tesnion loading (for example) and followed by torsional loading until failure. Next the specimen is first subjected to torsional fatigue, interupted and cycled to failure in axial tension. Such a test provides data to check the veracity of, and validate the new fatigue model being developed by the PI, with support from the ARO. The thermal camera allows measurement of temperature fields at the highest possible spatial and thermal resolution currently available in the market for the intended application. We are interested in measuring the thermal field and hence the conversion of mechanical energy to heat during the cyclic loading of polymers that are used as resins for fiber reinforced composites. This instrumentation is to be used in conjunction with ongoing ARO sponsored effort on Novel multiscale fatigue modeling of textile composites, W911NF1920045.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 31, 2022
- Source ID
- W911NF2210072
Entities
People
- Anthony Waas
Organizations
- Army Contracting Command
- United States Army
- University of Michigan