Session: 18: Student poster competition

Paper Number: 119156

119156 - Temperature Variance in Acoustic Emission From Thermoset Composites 

Elevated temperature applications of high-performance composites are limited by our understanding of how the failure of these materials progresses under high thermal and mechanical stresses. Existing nondestructive evaluation methods lack predictive capabilities, leaving a missing link between the extent of damage and the predicted residual strength of the damaged part. In this work, an attempt is made to identify the characteristic acoustic emission parameters and waveforms of damage mechanisms and to track them during tensile loading at increasing temperatures.  Physical evidence of damage mechanisms correlated to the acoustic signatures is observed through post-test fractography. Three different carbon fiber reinforced polymer (CFRP) materials (woven reinforced plies in a quasi-isotropic (QI) orientation, woven reinforced plies in +\- 45-degree angle-ply (AP) orientation, and unidirectionally reinforced (UD) plies in QI orientation) [PN1] are tested under cyclic tensile loading at temperatures between room temperature and Tg of the matrix. Parametric and transient acoustic emission (AE) data is collected and analyzed. Trends in cumulative energy and characteristic waveshapes [PN2] are compared and correlated to the damage observed through the measurement of secant and tangent moduli. Losses of stiffness due to viscoelastic effects in the matrix and global damage development are isolated and examined. Results provide insight into damage development in composites at elevated temperatures and may lead to improved prognostics of residual properties through non-destructive evaluation.

Presenting Author: Preston Noll University of Nebraska - Lincoln

Presenting Author Biography: Preston Noll is a dual master's student in Mechanical and Materials engineering at the University of Nebraska - Lincoln and the University of Rouen Normandie. He also participates in the Graduate School for Materials and Energy Sciences research honors society, funded by the Normandie Region. His current area of research involves using acoustic emission analysis to understand damage progression and predict the residual strength of high-temperature thermoset polymer-matrix composites. Preston has previous research experience in metal additive manufacturing and industry experience in pharmaceutical manufacturing and project management.