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EAS Doctoral Proposal Defense by Zhuoyuan Leng

Tuesday, December 17, 2024 at 10:00am to 12:00pm

EAS Doctoral Proposal Defense by Zhuoyuan Leng Date: Tuesday, December 17, 2024 Time: 10:00am Topic: Experimental and Numerical Studies on Mixed-mode Fracture of Additively Manufactured Polymer Nanocomposites Location: LIB 314 Zoom Link: https://umassd.zoom.us/j/92967323046?pwd=ppH0sI5z79H46F0rQhSkb2S4Y16mlA.1 Abstract: This study investigates the mixed-mode fracture behavior of ABS nanocomposites fabricated using fused deposition modeling (FDM) for automotive and aerospace applications. The scope includes quasi-static and dynamic mixed-mode fracture scenarios, and cyclic mixed-mode fatigue fracture properties, using experimental and numerical methods, focusing on understanding crack dynamics and enhancing the fracture toughness of ABS composites. It explores fracture criteria under mixed mode loading conditions and assesses the influence of printing direction, loading type, and nanoparticle weight percentage. The experimental methodology is divided into three parts: (1) quasi-static mixed-mode loading of ABS nanocomposites with different printing directions, (2) dynamic mixed-mode loading using a modified Hopkinson pressure bar setup, and (3) cyclic fatigue loading to assess fatigue fracture performance. Scanning electron microscopy (SEM) will be used to analyze fracture surfaces and correlate them to fracture mechanisms under various mode-mixities and loading conditions. Simulation studies focus on crack dynamics using the phase-field method (PF) implemented in COMSOL, with anisotropic material formulations to model different printing directions and dynamic loading scenarios. Comparisons between simulations and experiments will enhance the understanding of fracture mechanisms. The outcome can be used to optimize ABS nanocomposite performance and provide insights for structural applications. ADVISOR(S): Dr. Vijaya Chalivendra, Department of Mechanical Engineering (vchalivendra@umassd.edu) COMMITTEE MEMBERS: Dr. Caiwei Shen, Department of Mechanical Engineering Dr. Jay Wang, Department of Physics Dr. Jun Li, Research Associate Professor, ERAU NOTE: All EAS Students are ENCOURAGED to attend.

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https://umassd.zoom.us/j/92967323046?pwd=ppH0sI5z79H46F0rQhSkb2S4Y16mlA.1