Josiah Jungkuntz
Pronouns: he/him
Research Mentor(s): Minh Hoang Nguyen
Research Mentor School/College/Department: Aerospace Engineering / Engineering
Program:
Authors:
Session: Session 5: 2:40 pm – 3:30 pm
Poster: 101
Abstract
Carbon fiber composites have become increasingly popular in the material science community over the last few decades. Strong and durable, yet extremely lightweight, these substances have nearly limitless potential, especially within the world of aerospace structures. Research on the behavior of varying material types and stacking sequences subjected to tensile testing has already been presented in the literature to some extent, but further investigation will prove extremely valuable. Furthermore, previous studies have not studied the effect of transverse cracks (matrix failure) on the failure behavior of the specimen. This study aims to obtain and analyze the nonlinear stress-strain responses of three material systems (IM7/8552, T800S/2511, and T800S/3900), and six different stacking sequences. Each stacking sequence has one of two forms: [Theta_2/-Theta_2]s, (“4D-ply”), or [Theta/-Theta]2s (“8-ply”). Theta refers to the angle at which the ply is oriented with respect to the x axis (loading direction) and has values of 30°, 45°, or 60°. For each combination “dog bone” specimens with a width of approximately 12.5 mm at the gage section were manufactured via prepreg layup. The specimens were then subjected to tension using a Shore Western Tensile Tester. A Nikon camera directly faced the front side of the specimens and was set to take photos every two seconds during the test. A microscope attached to a custom mount captured video of the edge of each specimen. Stress data was captured by the machine’s internal data acquisition system while strain data was obtained from analyzing the camera images via GOM Correlate. This allowed for the plotting of stress-strain curves as well as detailed side imaging at several different stages of the test. The data analysis revealed that the Theta = 30° specimens tended to be strongest, followed by the 45° specimens, followed by the 60° specimens. In addition, 8-ply specimens were significantly stronger than 4D-ply specimens.
