AEROSPACE ENGINEERING

Abstract

Polymer matrix composites (PMCs) are becoming increasingly prevalent in structural, transportation, and aerospace applications. As such, accurately predicting their performance, particularly under dynamic loading environments is necessary. At the same time, the matrix influence due to its nonlinear rate-dependent response and shattering behavior during damage evolution remains largely unknown. This talk focuses on the role of the polymer matrix and explores potential intrinsic and extrinsic toughening mechanisms. Under quasi-static and dynamic compressive loading, nominally identical woven fiberglass composites with varying resin matrix binders exhibited localized shear band formation with characteristic geometry stemming from instabilities at the weave interface. Moreover, two-stage light-gas gun impact experiments reveal dramatically different ballistic limit behavior between nominally similar binders. Variations of DGEBA (epoxy-based) resins were examined under mode-I (crack opening) impact conditions in order to extract relevant dynamic fracture criteria for matrix shattering utilizing Digital image correlation (DIC), a full-field imaging technique, and high-speed imaging. Additionally, inverse techniques leveraging the Virtual Fields Method will be discussed in the context of extracting relevant rate-dependent tensile and shear material properties of PMC’s relevant for predictive modeling. These results can be used to tailor the microstructure and performance of PMCs, and are relevant in the development of next-generation additively manufactured thermosetting polymers.

Speaker

Dr. Leslie Lamberson

Associate Professor in mechanical engineering and mechanics, with affiliated appointment in materials science and engineering, at Drexel University. She received her bachelor’s in aerospace engineering from the University of Michigan, her master’s in aerospace engineering from Georgia Tech, and her doctorate in aeronautics from the California Institute of Technology. Prior to her faculty appointment, she was a postdoctoral research scholar with K.T. Ramesh at Johns Hopkins University. A former Lockheed Martin ‘Skunk Works’ engineer, in 2013 she was a NASA Glenn faculty fellow in the Materials and Structures for Extreme Environments Division. Her expertise lies in microstructurally-informed experimental mechanics under dynamic conditions.