SBIR-STTR Award

This proposal aims at developing an integrated approach for process and performance modeling in layered fibrous composites. It focuses on two critical issues in the manufacturing of fibrous composites: (i) modeling of voids, and (ii) modeling of wrinkles. Both aspects of micromechanical damage that get embedded in the morphology of the material at the time of its manufacture are known to have profound effect on the interfacial strength and fatigue life of the composite structural components. Process modeling part is concerned with the transient initial phase of the manufacturing of the material until the cure cycle is completed and it employs a two-pronged approach: A discrete micro-level (fiber-matrix level) approach, and a locally-homogenized macro-level (ply level) approach. Process Modeling effort is coupled with the Performance Modeling effort to investigate fatigue integrity of composites with embedded voids and wrinkles. A unique feature of our computational method is seamless and uniform coupling of the various hierarchical models in a variationally consistent fashion. A combined modeling, analysis and experimental validation program is envisioned for the calibration of theoretical and computational models as well as for sensitivity analysis of modeling parameters.;

Benefit:
This effort will result in a cost effective ICMSE based modeling and analysis tools for optimizing the processing technologies in the manufacturing of fibrous composites. The new methods developed under this project will be implemented in modular form so that they can be easily integrated into the research and commercial finite element analysis packages via User Defined Modular Interconnects typically provided by such programs. High end graphics tools will be integrated into the overall computational framework for easy comprehension of the intricate stress and interface fields that develop during the processing of composites. It will thus help material designers speed up the process design cycle for efficient manufacturing of fibrous and layered composites with very well calibrated properties.

This proposal aims at developing a material agnostic modeling and analysis capability to help understand the genesis of voids and wrinkles during the processing and curing of fibrous composites. It also develops a hierarchical framework to investigate the effects of these micromechanics defects on the interlaminar strength and fatigue life of curved composite structures. The overall effort is categorized into three parts: (i) Process Modeling part that deals with the initial transient phase until the cure cycle is completed, (ii) Performance Modeling part that investigates the fatigue integrity of composites with embedded voids and wrinkles, and (iii) Experimental Program on CT imaging and microscopy, that are applied in novel way to extract porosity data at early stage, and fatigues testing with wrinkled specimens along with DIC to extract residual interlaminar properties. Process modeling employs a two-pronged approach: A discrete micro-level (fiber-matrix level) approach, and a locally-homogenized macro-level (ply level) approach. A unique feature of our computational method is seamless and uniform coupling of the various hierarchical models in a variationally consistent fashion. A combined modeling, analysis and experimental validation program will help with the calibration of theoretical and computational models as well as for sensitivity analysis of modeling parameters.