1. 제 목 : Nonlinear Phononic Crystals: A New Building Block for Designing Structural and Sensory Systems

2. 연 사 : Professor Jinkyu Yang
              (William E. Boeing Department of Aeronautics & Astronautics, University of Washington, Seattle)

3. 일 시 : 2013년 9월 6일 (금) 14:00 ~ 15:00

4. 장 소 : 신공학관 301동 1420호

5. 내 용 :
A superb mechanism for impact mitigation and damage tolerance has been developed in hard biological systems, from beaks of birds to exoskeletons of crabs and lobsters, over the millennia. These natural materials exploit strategically arranged, periodic architectures of complex composites made of relatively weak constituents. Inspired by such clever biological systems in nature, we study how to design, fabricate, and characterize a new class of tunable material systems using phononic crystals, which are defined as an assembly of ordered elastic particles/rods in periodic architectures. These phononic crystals exhibit remarkable versatility in their dynamics responses in support of a wide spectrum of elastic waves from linear to highly nonlinear regimes. In this talk, I will introduce the fundamental wave dynamics and mechanics of different types of phononic crystals (e.g., helical and woodpile phononic crystals) with focus on controlling both linear and nonlinear waves in an efficient manner. Potential engineering applications of phononic crystals are also explored, including the development of lightweight and tunable structures that allow filtering, modulating, and mitigating external impact and vibrations. I will also discuss the design of a new sensory system using phononic crystals. This sensing device employs nonlinear solitary waves as novel information carriers for improved accuracy and sensitivity. Preliminary studies show that the phononic crystal sensor can successfully characterize bone mechanical properties for biomedical applications and also detect hidden delaminations in fiber-reinforced composite structures for aerospace applications. This solitary wave-based diagnostic method may offer a new perspective beyond the conventional structural health monitoring and nondestructive evaluation schemes.

6. 연사약력 :
• Assistant Professor, William E. Boeing Department of Aeronautics and Astronautics, University of Washington (8/2013 – present)
• Assistant Professor, Department of Mechanical Engineering, University of South Carolina (7/2011 – 8/2013)
• Postdoctoral Scholar, California Institute of Technology (7/2009 – 7/2011)
• Senior Engineer, R&D Headquarters, Samsung Electronics Co. (4/2006 – 6/2009)
• Ph.D., Aeronautics and Astronautics, Stanford University (6/2005)
• M.S., Aeronautics and Astronautics, Stanford University (9/2001)
• B.S. (Honors), Aerospace Engineering, KAIST (8/2000)

7. 문 의 : 기계항공공학부 안 성 훈 교수 (☏ 880-7110)