The PEER Student Committee is pleased to present our next spotlight in the "Meet the PEER Students'' Series. The series features students and postdoctoral researchers who conduct exciting research projects, engage in leadership activities, and perform exceptional work. This month, we have a special edition where we introduce ourselves, the PEER Student Committee members.
Laura L. Hernández-Bassal (2021-2022 PEER Student Committee Chair) is a Ph.D. candidate in the Department of Civil and Environmental Engineering at the University of California, Davis. As part of her research, she is currently evaluating uncertainties in analysis and assessment methodologies in performance-based earthquake engineering, under the supervision of Dr. Sashi Kunnath.
Chrystal Chern is a structural engineering Ph.D. student at the University of California, Berkeley working under the supervision of Professor Khalid Mosalam. Her main research aim is to investigate a digital twin methodology for structural health monitoring that incorporates AI/ML techniques for continuous model calibration and rapid damage assessment in bridges.
Bryam Astudillo-Carpio is a Ph.D. student at Oregon State University. His research with Professor Barbara Simpson includes the analysis of strongback frames. As part of it, he is working in the US-Japan collaborative research on frame-spine systems with force-limiting connections.
Rodrigo Silva-Lopez is a civil engineering Ph.D. candidate at Stanford University working under the supervision of Professor Jack Baker. His research aims to minimize the consequences of road network disruption generated by earthquakes through the development of optimal bridge retrofitting strategies. He is originally from Chile, so he has felt many earthquakes in his life, even a couple with a magnitude over 8.0 Mw, so he has been looking forward to getting involved in PEER even before university.
What made you interested in earthquake engineering?
Laura: I originally was interested in architecture, but I love science and math, and so that’s when I discovered structural engineering. After my junior year in college, I was an REU in 2012 for NEES (The George E. Brown, Jr. Network for Earthquake Engineering Simulation). As part of that program, I was exposed to many different research projects in earthquake engineering, which was my initial “motivator” for pursuing earthquake engineering.
Rodrigo: During my senior year of high school, we had a huge 8.8 Mw earthquake that lasted two to three minutes. I still have vivid memories of it. At the time I was searching for a way to apply my skills in science and math to work on something that I found interesting and helps my community. Seeing how the earthquake affected my community, I decided to get my undergrad in civil engineering, and since then I have discovered my interest in how we can take action to prevent the adverse consequences of earthquakes.
Chrystal: When I started graduate school, I wanted to gain a deeper understanding of structural analysis and modeling, and at the same time look into automation and optimization for problem solving in structural engineering. The field of structural health monitoring caught my eye and once I got involved, I found that each piece of the research problem of assessing performance after an earthquake was exciting to me. For example, continuous monitoring, data processing and analysis, dynamic structural analysis methods, and damage assessment have all been fun topics for me to look into. This got me hooked onto earthquake engineering.
Bryam: First, I have always liked mathematics and physics, so engineering was a good fit for me. On the other hand, I was born and raised in Ecuador. We are located in the Ring of Fire, just as the US west coast. So, we often experience seismic events. I thought structural engineering would be a good profession. Then, when I took a course on matrix structural analysis, and combined structures problems and programming, I knew that was how I wanted to put my skills to work for the welfare of society: doing numerical modeling, seismic analysis, and so on.
What are your current career goals?
Laura: I would like to go back to industry and work on interesting existing and new building projects. Through my graduate studies, I really enjoyed teaching, so I would love to be an adjunct professor teaching structural engineering courses.
Rodrigo: My long-term career goal is to use my knowledge from years of studying structural engineering, computer science, and artificial intelligence to mitigate the impact of natural disasters. I would like to expand my studies from earthquake engineering to other natural disasters, such as coastal hazards. My focus is to find out how to use these tools to make a greater impact on communities, whether through industry or academia.
Chrystal: I want to end up somewhere where I can continue exploring complex topics related to data science and resilience of the built environment, or other goals related to the well-being of both humans and the environment. I would also like the opportunity to build community among scientists and engineers. Right now, research and academia are a good fit for me, but I’m taking it day by day.
Bryam: I recently defended my MS thesis and transitioned towards my Ph.D. degree. As of now I am focused on publishing the work done at the E-Defense testing program and continuing to expand my research on the topic. Looking forward to when I am done with my Ph.D., I would like to explore opportunities to become faculty in the US or also contribute with agencies that have a research component in the area of seismic engineering.
What are your research objectives?
Laura: I’m currently working on evaluating analysis methods and modeling approaches within buildings for performance-based engineering. Specifically, I’m looking at steel moment frames and concrete shear wall buildings. I am performing ASCE-41 evaluations and assessing how we can improve the current guidelines. Therefore, one of my main research objectives is to have results and observations that can be used by practicing engineers in the near future and beyond.
Rodrigo: In the field of community resilience, I’ve been exploring how lifelines are affected by natural disasters, and how we can improve them to mitigate impacts on our communities. For example, we decompose the impacts of disasters into different factors and study whether some disproportionately affect communities– these can be socioeconomic or racial. The second part is assessing distributed systems, which are interconnected and complex models. The objective is to properly quantify the reliability of the system assessments given limitations on data and computational power. Finally, I study how to propose strategies that inform post-disaster decision-making.
Chrystal: My main research goal is to explore automation and optimization in structural health monitoring so that resilience in the built environment can be improved with safety and efficiency. For example, by taking advantage of sensors and data, we could potentially decrease the amount of field workers doing in-person inspection of structures after a potentially damaging event, and make decision-making about operability of structures more efficient. The particular way I am currently looking at this problem is by investigating a digital-twin methodology for structural health monitoring that incorporates model validation and updating as well as machine learning-enabled rapid damage detection and assessment.
Bryam: My research at OSU focuses on strongback systems for resilience structures. These are atypical configurations of structures that help to avoid story drift concentrations, and therefore they have a better structural performance. So, the first part of my research involved full-scale dynamic testing at the E-Defense shake-table. There we had a weak moment resisting frame, that we retrofitted with a massive column, that we called a spine to avoid the drift concentrations. This makes the system experience more higher-mode contributions or higher-mode effects that increase floor accelerations. So, the test also included a way to mitigate those higher-mode effects by adding some force-limiting connections to control the shear between the base frame and the spine. Now, we are extending the findings to explore more design methodologies and to quantify the system collapse performance using various archetypes and the FEMA P695 methodology.
What are some important aspects of your field of research?
Laura: My research is very practical. One important aspect of it that I really need to understand is how engineers in industry, at different firms, are actually using building codes. How are they modeling the buildings? What choices are they making when calibrating their models? This is important because we need to understand how they are doing it so that we can provide recommendations on how they could improve their current methods.
Rodrigo: I would say that the most important aspect of lifeline engineering against natural disasters is that it involves complex systems with thousands of components that are interrelated in a highly nonlinear way. Secondly, the performance of these systems involves original areas or communities, so we need to bridge the gap between complex techniques and policymaking. For example, when presenting optimization algorithms and machine learning techniques to give information on which bridges to retrofit, we ultimately still need to translate the information into a policy and explain what features impacted the bridge ranking and importance.
Chrystal: When using data science methods such as machine learning and optimization, it’s important to track the physical meaning of the structural behavior throughout the data manipulation process. At the same time, make smart decisions regarding model complexity to leverage the increase in computational efficiency that algorithms provide. This efficiency is necessary for rapid assessment and resilience. In addition, collaboration is essential to verify scripts and calculations.
Bryam: Since we deal with atypical systems in our research, it is important to have a clear understanding of typical systems designs prior to extending and proposing designs of alternatives such as the strongback systems. I would say it is important to have some expertise in programming. Especially since the tasks we do are more related to the numerical side of structural engineering. So, for example, if you want to quantify the performance of a structure, you will need to build a model, and if you plan to do Incremental Dynamic Analysis, the best way may be using something like OpenSees whose interface pretty much differs from commercial structural packages. Plus, learning how to code would make your life much easier in graduate school.
What activities in your research have been the most challenging?
Laura: It’s definitely tough to estimate how long something will take. In research, there are so many obstacles that come up and you often have to investigate more than you originally thought. For example, I’m looking at the system-level response of buildings but in the process, I have to make sure that all of the components that I am modeling are calibrated, ideally to experimental results. This time adds up and it’s hard to know how long it will ultimately take.
Rodrigo: One challenge is the computational time involved in analyzing such complex systems as transportation networks, and another is quantifying the impacts of road network disruption on communities and making sense out of them. As an example of the computational cost, the analysis of traffic in the San Francisco Bay Area for one seismic scenario takes six hours on my own computer, and to do reliable analysis I have to run about 2,000 scenarios. In terms of quantifying metrics, there are some weird cases that you don’t anticipate; for example if all bridges are collapsed, no one will be traveling, so travel time is zero. So it is difficult to quantify metrics and find out what those impacts mean.
Chrystal: It took me a while to figure out how to find and ask for support in getting set up in research, pinpoint what literature to study, and find community. It was likely due to starting my Ph.D. at the beginning of the COVID-19 pandemic, but luckily with the restrictions lifting a bit, I have been able to overcome these obstacles.
Bryam: One challenge was to guess the behavior prior to testing. We took a probabilistic approach. At the beginning, it was challenging to adapt to remote collaboration. But I think we are managing it pretty well now. Other than that, I have found challenging the part of writing about my research. Although I am aware that if you don’t write about your findings, then no one would know about it, it takes me some time to put all those results into text. I am grateful to my advisor who is constantly checking my work and providing feedback.
What advice would you give your former self at the beginning of your academic career?
Laura: Everything that you do is a learning opportunity. Even though sometimes you work hard on one specific part of the project that might not lead to something, you learned and that makes you a better researcher. I would tell my former self: at the end of each term, think about what you have done and what you accomplished and be proud of everything that you have done so far.
Rodrigo: You are doing alright, you are good enough, don’t stress yourself out too much. I feel like I fell into the trap of working too much and staying up late, but I could have been happier without doing so. Second, reach out to people and connect in terms of collaborating and enriching your grad school experience. It will open doors to research opportunities, especially in the realm of natural disasters.
Chrystal: Be patient – you are doing a great job and as long as you stick with it, it will click one day. Nobody starts out capable, and the only way to get capable is to do things.
Bryam: Keep up the curiosity, and the perseverance. Opportunities and learning experiences will come along the road. Be open and reach out to people and someone will be willing to help.
Can you tell us about any achievements or projects that you are especially proud of?
Laura: I’m proud to have been a co-founder of the graduate branch of CALESS, the Chicanx and Latinx Engineers and Scientists Society at UC Davis. It was great to create a community for graduate students to come together and support each other in their academic journey and professional development. I’m also very proud of continuing to work on my research as a first time mom and managing my time between my doctorate work and motherhood.
Rodrigo: Growing up in Chile, it’s really hard to access knowledge, sciences, and academic institutions. At my undergrad institution, I was one of the leaders of the Eldrich Office at the school of engineering and sciences. During one of my years there, I was the chief coordinator of a science fair held by our department. We had over 15,000 people visiting campus over the course of two days. I got to watch kids that had never set foot in a scientific institution have an instance of interaction with people in science. It was a really nice feeling to watch them realize that they can access such spaces in the future, when they were previously taught otherwise.
Chrystal: I’m proud that I’m still here doing my Ph.D. studies even though it’s been difficult. It’s probably tough for a lot of students to feel like they belong in such a program, and I definitely experienced that, so I’m proud that I stuck with it. I’m also proud to be taking on a leadership role as a coordinator of my current research project, which involves a lot of collaboration.
Bryam: I am proud I was able to get a Fulbright scholarship to study here in the US. Since I was completing my undergraduate I knew I wanted to do my graduate studies at a PEER institution and that scholarship helped me achieve that.
Other fun facts about the PEER Student Committee...
If a movie was made of your life, what genre would it be? Or, what is your favorite movie genre?
Laura: I don’t have a favorite type of movie but I got really into the MCU (the Marvel movies) during the Pandemic. I like how they are all interconnected and you need to understand all of the movies to get the major plot.
Rodrigo: My movie would be a drama – not because my life is dramatic, but because life is made up of a little bit of comedy, horror, action, and sadness, and drama is a combination of all of them.
Chrystal: I love movies and TV that combine comedy, mystery, and drama.
Bryam: It will be a mix of many genres, just like life. Some mystery, suspense, comedy, romance. But in general, I like suspenseful thriller movies, those that play with your mind a little.
What is your favorite animal?
Laura: I like all types of flying creatures, but I love hummingbirds and the way they move around. I love staring at them and seeing how they move dynamically in all directions.
Rodrigo: My weiner dog, Pancito (which translates to little bread) who lives in Chile with my sister.
Chrystal: Lefty, my 13-year-old dog.
Bryam: You can probably say I like beavers now because of OSU.
What has been your favorite moment in graduate school so far? Or, what is your favorite thing about grad school?
Laura: One of my favorite parts of grad school is actually taking the qualifying exam. At that point, all my knowledge from all the courses was fresh in my mind and I understood how the subjects were interconnected. In terms of course material, this felt like the climax of my education at UC Davis.
Rodrigo: One of my fondest memories was attending the 2018 PEER meeting during my first year of grad school. I was starstruck when I met the same professors who I read so much about and whose papers and books I based my studies and research thesis on in undergrad. That year, the event was held in Berkeley, which is six thousand miles away from my original home in Chile. It was impressive to see researchers from all across the world gathered together in the same place to discuss what I was passionate about.
Chrystal: I have a few favorite things. They include (1) the opportunity to continue taking classes and learn in a structured environment, (2) the freedom I have to explore new problem solving methods and complex topics, and (3) meeting and working with people who share these interests.
Bryam: The best experience so far was when we were testing our full-scale specimens in the E-Defense shake-table in Japan. Although we couldn’t travel due to COVID, we were totally involved in the testing through online communication with our collaborators.
What hobbies do you enjoy?
Laura: I like dancing salsa, merengue, bachata, swing, samba. I also love board games! I like Ticket to Ride, Dominion, Panam, Pandemic, Settlers of Catan, among others.
Rodrigo: In my free time, I swim a lot, and I love meeting up with friends to play board games. I also really like to go to the art museums on campus.
Chrystal: I like art, making things, hiking, yoga, dancing, hanging with my dog, and napping.
Bryam: I like to play soccer. I am down to try other sports as well. I would say coding is another “hobby” and “job” I enjoy.
What’s something you would put on your bucket list?
Laura: I love traveling and one of my bucket list countries is Egypt.
Rodrigo: I promised myself that after graduating, I will learn to play piano and sing.
Chrystal: I want to learn to surf.
Bryam: I would love to go to the FIFA soccer world cup. The 2026 edition will take place in the US too, so that might be a good chance to attend.
Which course did you enjoy the most in school?
Laura: I loved all of my classes but I really liked Advanced Structural Matrix Analysis, because it combined theory and coding. I had to code my own structural analysis program so I found it enjoyable trying to come up with a code that was efficient. Now it’s a resource that I can use in the future for myself!
Rodrigo: One of my favorite classes in grad school was Artificial Intelligence. I learned that I can code well and I got to teach pacman how to win the game for an assignment. We also had lectures on image recognition, which I used to train a neural network to recognize whether photos contained my dog or not.
Chrystal: I’ve really enjoyed all my classes at Berkeley. One of my favorites was Data 100: Principles and Techniques of Data Science.
Bryam: I really enjoyed Risk and Reliability Analysis, combining probabilities with numerical analysis.
Watch the previous Meet the PEER Student spotlights on the PEER Student Committee website. Do you know someone in the PEER institutions who is doing a great job? Nominate them here to be part of this series.