S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Mechanical Aerospace Engineering (기계항공공학부) Theses (Ph.D. / Sc.D._기계항공공학부)
A Study on Micro Shock Waves in Solids using the VISAR Interferometry Technique
바이자 간섭 기술을 활용한 고체 내 미소 충격파 연구
- Hyeonju Yu
- 공과대학 기계항공공학부
- Issue Date
- 서울대학교 대학원
- 학위논문 (박사)-- 서울대학교 대학원 : 기계항공공학부, 2017. 2. 여재익.
- Since the early 1900s, as the space and defense industry gained importance, interest in high temperature and pressure phenomena such as collisions, explosions, and the use of energetic materials has been continuously increasing. The properties of materials under extreme conditions such as high temperatures and high pressures are significantly different from those observed under normal atmospheric environment. However, information about the response of condensed matter in extreme conditions is still lacking and needs to be studied.
Plasma-driven shock compression is a promising technique that can generate high-pressure shocks at the laboratory scale in contrast with conventional large-scale high-pressure generators such as gas guns, powder guns, electric guns, and rail guns. Moreover, a plasma-driven shock system has significant advantages in terms of lower cost, lesser time consumed, better control, higher repeatability, and ease of miniaturization of the system. Therefore, in the present study, experiment and numerical analysis were carried out in order to analyze the behavior of plasma-driven micro shock waves with extremely high pressure and short duration.
Diverse plasma-driven shock generators, such as laser-generated shock waves, a laser-driven flyer, and an exploding foil initiator, were developed for access to high pressure and precise control. A high-speed diagnostic using an instrument termed “Velocity Interferometer System for Any Reflector” (VISAR) was conducted to determine the performance characteristics of the developed plasma-driven shock systems. Numerical analysis was also performed for the verification of experimental results and for overcoming experimental limitations.
In this study, all aspects of the system including laser-matter interaction, plasma-driven shock waves, flyer acceleration, shock loading by flyer impact, and shock behavior in solids have been discussed. Therefore, the reported results establish the basis for future shock studies by providing a design guideline for a robust and optimized micro shock system.