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MAE PhD Defense – Felipe Robles Poblete
October 5 @ 1:00 pm - 3:00 pm
TITLE: Rate-dependent Interfacial Mechanics in Advanced Material Systems
ADVISOR: Dr. Yong Zhu
DATE & TIME: Friday, October 5, 2018 at 1 PM
LOCATION: EB3 – 3235
An important branch of applied mechanics involves the category of problems which examines the mechanical behavior of contact regions. There are an extensive number of engineering applications that require one material to be bonded to another. Examples of these applications include adhesive joints, composite materials, protective coatings, and thin films used in the fabrication of microelectronics devices. A great deal of research has been devoted in order to develop techniques to predict the strength of the bond by endowing the interface with its own characteristic constitutive response, rather than plainly assuming it to be frictionless or perfectly bonded. In this dissertation, rate-dependent contact problems in different advanced materials systems were studied in order to better understand their behaviour at certain loading conditions. First, the interlayer mechanical properties and adhesion between glass and SaflexTM polyvinylbutyral (PVB) was studied. The adhesion characterization was accomplished by carrying out mode 1 and mode 2 fracture mechanics experiments of laminated glass-PVB specimens. Second, this work reports on the nonlinear and cohesive shear-lag analysis of the interfacial shear stress transfer between a single silicon nanowire (SiNW) on top of two types of substrates under tensile loading: nontreated and 45 min. UVO-treated poly-(dimethylsiloxane) (PDMS). Similar analysis was used in the interfacial characterization between silver nanowire (AgNW) and PDMS substrate, which is applied in the study of not only the stretching, but also the buckling and fracture of AgNWs. Last, the contact modeling of the nanoindentation of aluminum oxide (Al2O3) and zinc oxide (ZnO) nanolattice films is presented.
Felipe Robles Poblete is from Sao Paulo, Brazil. He obtained his bachelor’s degree in aeronautical engineering from the University of Sao Paulo in 2012. Following graduation he joined Dr. Zhu’s lab at North Carolina State University and in 2014 he decided to pursue a PhD degree under Dr. Zhu’s guidance. His research interests include interface mechanics, mechanical testing, and finite element modeling.