High Rate Testing and Simulation of Composite Fastener Joints

The NASA Advanced Composites Consortium (ACC) High Energy Dynamic Impact (HEDI) program was a multi-institutional effort uniting NASA, the FAA, major aerospace OEMs (Boeing, Lockheed Martin, GE Aviation, UTC, Spirit AeroSystems), and academia -including Wichita State University and NIAR as named consortium members- with the goal of developing and validating Progressive Damage and Failure Analysis (PDFA) methods for high-velocity impact events relevant to aircraft certification, specifically fan blade containment, bird strike, and fuselage shielding scenarios.
The program's validation methodology followed a building block approach, which required coupon-level material characterization to populate the property inputs feeding PDFA models in LS-DYNA (MAT162, MAT261, MAT213, and Peridynamics formulations). This material characterization layer is where the present contribution was situated.

Upon joining the Materials Research Group at what was then the Computational Mechanics Lab (now AVET-NIAR), on of my initial assignments required me to integrate into an ongoing coupon-level experimental campaign operating under the NASA ACC HEDI program, where I contributed alongside an established team. The group was running mechanical testing on an MTS load frame instrumented with a Digital Image Correlation system, a full-field optical strain measurement approach particularly well-suited to capturing the heterogeneous deformation behavior of composite specimens that point-based extensometry would either miss or misrepresent. My contributions within this team effort spanned specimen documentation, raw data extraction and reduction from DIC outputs, translation of the measured strain fields into material property inputs for LS-DYNA material card development, participation in card verification and validation exercises, and co-authoring portions of the deliverable reports submitted to the consortium.
Beyond the technical learning curve, what stayed with me most was the leadership of Adrian "Lemonchete" Gomez Fernandez. Working under Dr. Raju's expertise on high-rate material characterization was eye-opening in its own right, and the fast ramp-up across tooling, DAQ systems, and software packages was its own education, but Adrian's ability to navigate the human side of technical work left a more lasting impression. He held a rare balance: solid engineering judgment, genuine approachability, the willingness to push back when needed, and a grounded instinct for keeping ambitious work tethered to feasible outcomes, all while managing a team drawn from genuinely different backgrounds and cultures. He was the reason I chose to continue with the materials research group when I started my PhD, and his departure left a noticeable gap that no one could quite fill.