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Non-invasive characterization of fiber reinforced automotive composites through thermography


Title: Non-invasive characterization of fiber reinforced automotive composites through thermography

Authors: Hannah L. Maeser, Dayakar Penumadu

DOI: 10.33599/nasampe/c.23.0085

Abstract: Fiber reinforced composite materials are being targeted for improving fuel efficiency through weight reduction and crash worthiness through crushing in commercial automobiles. Composite systems with lower-cost precursor materials and faster cure times such as sheet molding compounds (SMCs) are being developed and tested as cost-effective composite solutions for the automotive industry. In addition to low-cost material systems and manufacturing methods, real-time quality inspection methods are needed to maintain safety in performance along with cost-effectiveness. Rapid nondestructive evaluation methods are needed to inspect composite automotive parts for defects during manufacturing. The current study applied two thermography-based nondestructive inspection methods for identifying anisotropic behavior in large-scale, low-cost fiber reinforced composite automotive parts. One method used was thermal digital image correlation (TDIC). TDIC is a novel, nondestructive evaluation method being developed to identify regions of high anisotropic behavior such as delamination and fiber misalignment in thermally loaded fiber reinforced composite parts. Such a method is expected to be helpful in monitoring fiber flow and orientation in large scale SMC automotive parts as a result of material processing through optimal charge placement. The second method used was flash pulse thermography, a well-known nondestructive evaluation method that has been used for years in the aerospace industry to inspect for defects in composites. Flash pulse thermography analyzes the thermal energy resulting from a high-powered pulse exciting the surface of a part. The excitation induces a thermal gradient between the front and back surfaces of the part, and differences in cooling are tracked with a thermal camera as the energy dissipates into the part, allowing one to inspect through-thickness material behavior. Flash pulse thermography is expected to be helpful in detecting defects such as delamination, foreign object inclusions, and resin rich zones in composite parts. TDIC has potential for measuring parts during manufacturing, where thermal load can be supplied during molding or other manufacturing processes. Flash thermography is well suited to characterize parts coming out of injection and compression molding processes before part assembly. The NDE methods used to inspect composite automotive parts need to fit the manufacturing process to support reduced cycle times.

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Conference: CAMX 2023

Publication Date: 2023/10/30

SKU: TP23-0000000085

Pages: 15

Price: $30.00

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