AE Seminar
"Interfacial Mechanics of Aerospace Coatings under High-Rate Loading: Probing Buried Interfaces via Stress-Wave Control"
featuring
Junlan Wang
Steve & Lynn Pratt Professor of Mechanical Engineering | University of Washington
Friday, April 24
3:00 - 4:00 p.m.
Guggenheim 442
About the Seminar:
Protective coatings play a critical role in aerospace systems, where surfaces are routinely exposed to extreme environments such as high-velocity rain and particle impact. The durability of these coatings is often governed by interfacial rather than bulk material properties, yet quantitative measurement of adhesion at buried interfaces within multilayer architectures remains a significant challenge. In this talk, I will present a mechanics-based experimental framework for isolating and quantifying interfacial adhesion in multilayer aerospace coatings using a pulse-shaped laser spallation technique. By tailoring stress-wave evolution through pulse shaping and layer thickness control, we demonstrate controlled migration of the failure plane, enabling selective interrogation of specific buried interfaces under nanosecond tensile loading. The methodology is applied to polymer-based rain erosion coating systems relevant to aircraft applications, where the results reveal distinct dynamic adhesion strengths across coating interfaces and a transition between adhesive and cohesive failure at high strain rates. These findings provide new insights into how stress-wave propagation, impedance mismatch, and coating architecture influence failure initiation under dynamic loading conditions, and demonstrate how experimental mechanics approaches can inform the design of more durable coating systems for aerospace applications.
About the Speaker:
Junlan Wang is the Steve & Lynn Pratt Professor of Mechanical Engineering and an Adjunct Professor in Materials Science and Engineering at the University of Washington. Her research focuses on experimental mechanics of thin films and multilayers, high strain-rate phenomena, laser–material interactions, and additive manufacturing. She received her B.S. and M.S. in Mechanics and Mechanical Engineering from the University of Science and Technology of China, and Ph.D. in Theoretical and Applied Mechanics from the University of Illinois at Urbana–Champaign, followed by postdoctoral training at Brown University. She began her academic career at the University of California, Riverside before joining the University of Washington. Some of her honors include the NSF CAREER Award, ASEE Beer and Johnston Outstanding New Mechanics Educator Award, and the Society for Experimental Mechanics Frocht, Durelli and Hetenyi Awards. She is a Fellow of ASME. She currently serves as President of the Society for Experimental Mechanics (2025–2026) and Editor-in-Chief of Experimental Mechanics (2025–2029), and as Associate Chair for Academics in Mechanical Engineering at the University of Washington.