August 23, 2022

Jin Yang joins us in the Department of Aerospace Engineering and Engineering Mechanics at UT Austin as an assistant professor this fall. The Yang Research Group missions include developing analytical tools and experimental techniques to study viscoelastic materials behavior, dynamic instabilities and material failure under extreme loading conditions. His research activities include investigating the high-strain-rates of soft material which can undergo extremely large deformations and can be easily damaged such as hydrogels, tissues, and foams; and developing fast and accurate digital image/volume correlation methods, which Yang refers to as a powerful experimental technique, for quantitively measuring 2D and 3D full-field deformations in solids.

Yang uses a combination of experimental loading to develop measurements and theoretical framework to better understand the mechanics of the materials he is investigating. Examples of real-world applications of his work include gaining a better understanding of human tissue, which could aid in the treatment of laser eye surgery, breaking up kidney stones, and even understanding brain injury, along with many other types of engineering applications where fluid-solid interaction resulting in cavitation collapse might cause irreversible material erosion.

Yang earned his Ph.D. at the California Institute of Technology in solid mechanics under the supervision of Kaushik Bhattacharya. Most recently he worked with Christian Franck at the University of Wisconsin-Madison as a postdoctoral research associate.

What attracted you to Texas ASE/EM?

This department is very famous in the area of mechanics. ASE/EM alumni have big names and I knew about those alumni even while I was pursuing my Ph.D. at Caltech. Also, the Cockrell School is a highly ranked engineering school – currently number six in the U.S. So I knew this was a good department with a high-quality reputation for both faculty and students. There are also a lot of opportunities for collaboration and I will have the ability to attract graduate students who can help me reach our group’s research goals. Also, Austin is a very nice city!

What do you enjoy most about your research?

First of all, I love exploring new things, such as discovering new mechanics. I find solid mechanics, which was my Ph.D. major, very interesting. Materials can have a wide variety of behaviors such as buckling, instabilities or even fractures or fatigue, and these behaviors are quite different depending on whether they are under slow or fast loading rates. Materials also have so many uses – from building secure bridges on Earth to launching satellites to space to developing medical applications that are safe for patients. So it’s very important to understand the mechanics of these materials. I know mechanics and I know the math, which helps me to understand the mechanics of these materials. I can then use this knowledge to help people.

Tell us about your teaching philosophy.

I will be teaching the statics course to undergraduate students my first semester. My teaching philosophy depends on whether I am teaching an undergraduate or graduate course. For the undergraduate courses that usually include students from many majors, I work to make sure these students understand the core concepts of the course – or the “big picture” – and how it applies to their major. In my graduate courses I will be teaching much smaller classes and they will cover more advanced, research-based topics. Maybe there will be some open questions for students that can be combined with their own research projects. I am also very excited to mentor undergraduate students who are interested in research.

How do you like to spend your free time?

In my leisure time, you can find me in a gym lifting weights or jogging along the street. I also enjoy reading books when I am free.

Yang is affiliated with the Center for Mechanics of Solids, Structures and Materials. Learn more about Yang's work on his research website.

The figure below, representative of his research, shows the micro-cavitation-based rheometry method to characterize viscoelastic properties of soft gel-like materials at ultra-high strain rates (> 10^3 s^-1) by utilizing laser-induced cavitation.

research image representing work of jin yang
Figure 1. Laser-induced inertial cavitation in soft materials. (a) The lifespan of a laser pulse induced inertial bubble in an 8% polyacrylamide hydrogel: (I) Initial bubble growth phase; (II-III) Bubble undergoes collapse and expansion oscillations due to the interaction between the internal gases and the surrounding viscoelastic soft material; (IV) Bubble finally dissolves in a diffusion-driven process. (b) Complex bubble shape instabilities corresponding to different time points (red boxes in (a)) are experimentally measured and theoretically studied. (c) Full-field deformations in the surrounding material are experimentally measured by our developed spatiotemporally adaptive quadtree mesh Digital Image Correlation technique.