Uncertainty quantification of fiber orientation distribution measurements for long-fiber-reinforced thermoplastic composites. (June 2018)

• Record Type: Journal Article
• Authors: Sharma, Bhisham N; Naragani, Diwakar; Nguyen, Ba Nghiep; Tucker, Charles L; Sangid, Michael D
• Is Part Of: Journal of composite materials. Volume 52:Number 13(2018)
• Page Start: 1781
• Page End: 1797
• Publication Date: 2018-06
• Subjects: Long-fiber thermoplastics -- injection molding -- fiber orientation distribution measurement -- uncertainty quantification -- elastic properties; Composite materials -- Periodicals; Composites -- Périodiques; 620.118
• DOI: 10.1177/0021998317733533
• Languages: English
• ISSNs: 0021-9983

Abstract

We present a detailed methodology for experimental measurement of fiber orientation distribution in injection-molded discontinuous fiber composites using the method of ellipses on two-dimensional cross sections. Best practices to avoid biases occurring during surface preparation and optical imaging of carbon-fiber-reinforced thermoplastics are discussed. A marker-based watershed transform routine for efficient image segmentation and the separation of touching fiber ellipses is developed. The sensitivity of the averaged orientation tensor to the image sample size is studied for the case of long-fiber thermoplastics. A Mori–Tanaka implementation of the Eshelby model is then employed to quantify the sensitivity of elastic stiffness predictions to biases in the fiber orientation distribution measurements.