Fracture of Soft Materials (Fall 2023)
In this course, students will develop a comprehensive understanding of the mechanics of soft materials and learn about their fracture, fatigue, and adhesion. In addition to theoretical concepts, students will also be introduced to various experimental methods used to measure the mechanical and fracture properties of soft materials.
Polymers (Freely-jointed chains, Kuhn length)
Polymer networks (Gelation, Affine deformation, Thermodynamics, Entropic elasticity)
Modulus (Crosslinks, Entanglements)
Constitutive models I (Neo-Hookean, Aruda-Boyce, Gent, Mooney-Rivlin)
Constitutive models II (Gels)
Basics of finite deformation theory
Energy release rate (Thermodynamics, Small-scale yielding, Toughness)
Crack-tip field (Plane-strain condition, Airy’s function, Singularity, G-K relation)
Linear elastic fracture mechanics (G-annulus)
Energy dissipation (Viscoelasticity, Plasticity)
Fatigue fracture (Resistance Curve, S-N curve, v-G curve)
Rivlin-Thomas methods (Pure-shear, T-peeling, 90-peeling)
Case study (Interpenetrating network, Highly entangled network, Dynamic network, Composite, etc)
Teaching Fellow Experience
Introduction to the Mechanics of Solids (TF for ES120, Undergraduate, Harvard University)
Awarded Certificate of Distinction in Teaching.
Statics: Free Body Diagrams / Trusses
Stress and strain
Yield and fracture criteria
Torsion and bending
Deflection and shearing of beams (including statically indeterminate beams)
Transformation of stress and strain
Stability and buckling
Ordinary and Partial Differential Equations (TF for AM105, Undergraduate, Harvard University)
Initial value problem
System of ODEs
Series expansions and Fourier series
Separation of variables
Heat equation, Wave equation, Laplace equation
Engineering Thermodynamics (TF for ES181, Undergraduate, Harvard University)
"An introduction to thermodynamics: Basic algorithm of thermodynamics (BAT) and its applications" written by prof. Zhigang Suo
Solid Mechanics (TF for ES240, Graduate course, Harvard University)
Applications of MEMS in Mechanical Engineering (TF for 446.355, Undergraduate course, Seoul National University)
CMOS process and its applications
Micro-nano patterning technology
Anonymous Student Quotes
"Junsoo ensured students learnt the important core concepts, not just the applications required for problem sets."
"Junsoo is one of the best teachers I have had here, everything he says is useful to understanding. I looked forward to every one of his sections. He is enthusiastic and shares all of his knowledge!"
"I don't think I've ever learned so much and so much useful information in any of my classes before. I really felt like I settled into being a future mechanical engineer this semester."
"This is a hard course, but the staff are here to help you and if you want to succeed they will help you, and you will succeed."
"I have never met a more iconic teaching staff"
"Junsoo was excellent and explaining the problems and material in a logical, clear manner. Very accessible outside of class."
"Junsoo is one of the nicest people I have met, and he is an incredibly effective TF. He is always available to answer questions and is very thorough in his replies."
"Junsoo was by far the kindest and most helpful out of all the TFs. I really appreciated how flexible he was and available he was for additional instruction. He was encouraging and willing to take the time to explain any of the concepts covered in the course as well as more theoretical questions outside the scope of the course."
"Junsoo was the type of TF you would adjust your schedule to attend his section. He always had a smile on his face and you can feel the enthusiasm from him at all times."
"I did not have Junsoo for section, but attended his office hours. Junsoo really aimed to give fundamental understandings along with helping us understand the problem. The amount of time he spent helping me work through weird questions and applications I came up with really helped me get a better grasp of the material. He was also always very accessible outside of class."