Ultra-Reliability Evaluation Based on Multi-Property Degradation Mechanisms
Abstract
The reliability of composite materials when exposed to multiple degradation environments was characterized. First, a new procedure based on inverse analysis and experimental measurements was established to characterize the transient moisture diffusion process in composites as a function of relative humidity and temperature. This procedure accounted for the heterogeneous microstructure in considerable detail, and was utilized to obtain the diffusivity and the maximum moisture content of the epoxy phase, and to determine stress distributions in the composite. In addition, high-grade composite laminates were exposed to various environmental conditions to characterize synergistic mechanisms of degradation. It was observed that the environmental factors such as UV radiation and condensation act synergistically to produce extensive material degradation. Mechanical testing was employed to determine the effects of such degradation on properties such as modulus, strength, and residual modulus under fatigue. Finally, a new technique based on optical fiber sensors was designed to detect and quantify embedded delamination and damage states via smart post-processing of measured data. This task required formulation of various inverse methods to process data to quantify unknown parameters. The results from this research have been made available to the composites community via numerous publications and presentations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADA412210
Entities
People
- Raman P. Singh
- Toshio Nakamura
Organizations
- State University of New York