Meet Cláudia Reis, New I-CPIE Faculty Member

How was your first semester at Lehigh?

Good. I had the opportunity to develop a new graduate course on coastal and offshore infrastructure engineering. It was exciting to prepare and an opportunity to re-learn and refresh a lot of concepts. I received the feedback from my 15 students today, and it was a great feedback with important insights to address for next year.

One of the priorities will be to enhance our resources to conduct a better hands-on experiment. Because I started in January, I didn’t have the right equipment to do it, so we improvised a manual piston generator to make waves. But that was super hard to have the right wave characteristics, because it was not mechanical. Definitely a point for me to improve. I am looking at the market to see what they have for educational purposes and some of my own experiments.

How big are they?

The one we used the past semester was about 120 centimeters [about 47 inches]. It’s not very big, yet depending on the budget we can look for other flumes to show 2D wave characteristics or a basin to show 3D wave transformations. I don’t think I have the budget for the basin at this point—we need to wait to see what the future holds in terms of funded proposals.

Where were you before you came to Lehigh?

I did my structural engineering studies in Lisbon, at Instituto Superior Técnico. It’s the best engineering faculty in Portugal and a leading one on the European ranking. Then, I did a very short postdoc at Oregon State University [Corvallis]. I started in March, by the end of March I was interviewing for Lehigh and, in May, I got the job offer that I accepted, of course. First, for the professional opportunity to become a faculty member at the renowned Lehigh University and second it also has a more personal side. I really, really enjoyed Oregon State. It has amazing facilities for hydrodynamic studies, the West Coast is beautiful, but it takes 20-plus hours to get home. From here I can have a direct flight to Lisbon and I am with my family and friends.

To highlight how much I enjoyed my experience at Oregon State University, I just want to add that Lehigh was the only university that I applied to, I was not in a hurry to leave, but it was like love at first sight with the job description that I would have here in Lehigh. I thought, I need to be applying for this one, and I’ll try my best to become, at least, one of the top candidates. And it worked!

What was it about the job description that really spoke to you? Do you remember anything specific?

I first became aware of what Lehigh was doing in NHERI [Natural Hazards Engineering Research Infrastructure, a National Science Foundation research center focused on infrastructure resilience], and it was life changing for me. During my PhD I became a committee member of NHERI, which lead me to attending one of the NHERI Summer Institutes in Texas in 2022.

Two funny curiosities about that event: 1) actually, I was the first foreigner working abroad to become a member of NHERI as I was always looking for scientific and engineering novelties in the field of risk management due to natural hazards, and 2) it happened a week before I defended my PhD thesis. So, when I arrived to San Antonio I was questioning my life choices. What am I doing here? I should be preparing for my thesis. And this was like Sunday morning, right? But, after the first day at the conference, I was so happy and overwhelmed to attend that workshop. I could never have had a better thesis defense preparation. After learning about NHERI’s consortium, representing 13 of the largest experimental facilities that the US has, including Lehigh, and about the cutting-edge research conducted at these facilities—and still feeling that my work was innovative and a contribution in the framework of NHERI was a boost of confidence! The following week I was more than prepared to discuss the work I have done during my PhD, contextualize it in European and North American advances and shortcomings, and describe my future research. That Summer Institute definitively marks the point where I decided to come to the US and do my work here.

So, shortly after attending this event and knowing that I had the postdoc position at Oregon State, the job description for Lehigh was published and it was just a perfect fit to my experience and interests on the characterization of multi-hazards impacts on critical infrastructure. I don’t remember one point that I thought would be a challenge, except my own perspective of career progression in Europe. In Europe it is usual to have longer postdoc(s). I did my thesis in November, and I was applying to Lehigh in December, so I thought there was no way they could consider me. Yet I had a great mentor during my PhD, that later became my PhD postdoc advisor, Dr. André R. Barbosa, who really supported me in applying. I’m so lucky to have him as a friend, always supportive to every idea that I have, providing so much guidance. And, just to show you how special NHERI was and is, another one of the NHERI members, Dr. Antonio Bobet, also sent me the job description: “This is you” he said, and he made sure I was not wasting the opportunity. “You need to apply” was his persuasive recommendation.

It's good to have those mentors in your life.

Oh, I am lucky that over my life I have always found good people and mentors and friends. For Lehigh, André and António gave me the confidence that I didn't have to apply, it worked, and I am here.

Can you explain some of your key research key terms, to demonstrate what you do in your research? The first one is cascading threats, or cascading effects?

Well, my background is in structural engineering, but for many years I was in the gray areas of structural engineering, first with earthquake engineering, then adding that tsunami engineering to my research. I was super lucky to work with a multidisciplinary team, including people from geophysics to help me understand the natural phenomena, people from mathematics to help me model it when interacting with infrastructure.

When I mention cascading effects it is from the natural hazard perspective. For example, a tsunami is always a secondary effect of a primary hazard, like an earthquake, a landslide, a meteor, and more recently, differential pressure on atmospheric pressure that can cause meteotsunamis. In my research, I focused on tsunami generated by tectonic sources. Regional and local tsunami are generated up to 300 kilometers from the source, and when you have an earthquake strong enough to be felt at this distance, that earthquake can probably generate a tsunami, if the source is in the ocean. Because the tsunami propagation relies on a conservative energy system, tsunami waves can travel the ocean and affect offshore and coastal structures that were subjected to ground motions from the earthquake before. Thus, on the engineering perspective, successive analysis accounting with cumulative effects of the cascading loads are essential to assess the partial or total loss of structural resistance between earthquake and the incoming tsunami.

The challenge is related with natural hazards and being tackled individually while bridging the gap between scientists and engineers remains a goal, even after some tsunamigenic earthquakes, such as the Tohoku-Oki 2011 in Japan, highlighting the how much the interaction between both natural hazards and engineers can be important. We are underestimating the risk to our communities by neglecting the cascading effects of natural hazards and their interaction with fluid-soil-structure systems built on our coasts.

Do the different effects amplify each other?

They do not. What they amplify is the potential damage to the structure. Usually an earthquake with a source in the ocean and magnitude above around 7.5 has tsunamigenic potential. When the magnitude is high, again like the M9.0 Japan event in 2011, the seismic waves have high values of acceleration and the tsunami waves are huge and fast.

Both waves on the fluid-soil-structure system represent a lot of interactions. The seismic waves are generating strong ground motions on the soil and foundations, while the fluid can affect soil and structure. Most of the time these interactions are not addressed due to the lack of understanding and the complexity inherent in having physical and numerical simulations to help understand it.

Lately, scientists and engineers, of course I am included in that group, are more aware of the importance of considering multi-physic interactions. In my case, I even prefer to look at elevated structures, such as ports, bridges, buildings with a first floor higher than ground level, and offshore platforms, because they are less explored in the literature than vertical structures, like buildings and coastal defenses. The main difference is that, in elevated structures, we need to account for both horizontal and vertical wave effects. In the vertical direction, the wave load exerted on the soffit of the structure may even be influenced by another fluid, the air. The influence of entrapped air is something that we also need to understand when designing our infrastructure.

Again, all these multi-physics are complex and represent highly non-linear processes, yet, I trust in the work that many talented people and myself are developing and I am optimistic about future outcomes.

Another key phrase is performance-based engineering? What is that?

It’s very related to all these interactions that I’m talking about. When you are designing an infrastructure, you can design it for different levels of performance. These levels are usually a function of the social and economic importance of the infrastructure. For example, a shed used for agricultural purposes plays a less important role than a critical infrastructure, such as water and power networks, air, land and maritime transportation, communications, healthcare—everything that you need to be functional after a disaster. Most of these even share the role of lifeline infrastructure in case of emergency. Thus, it is determinant for the recovery of communities located in hazard-prone regions that critical infrastructures have small to no downtime interruptions, even in case of an extreme event.

To assure such level of performance, and considering that failure is a chain-event, all elements composing the infrastructure need to be designed to high loading patterns. Of course, there is a sweet spot between designing resistant systems and controlling constructions costs and this is why it is so important to reduce the uncertainty associated with cascading loads and fluid-soil-structure interactions.

I am working with people from Europe and from the US toward this goal so we can move towards more resilient communities.

Another key concept is coastal. Is it just where the ocean meets the shore, or does it mean more in your research?

Yes, coastal is where the ocean meets the shore, considering an interval from a seaward to a landward distance deemed necessary to understand the phenomena involved in the processes.

Can you describe your research areas?

I like to be involved in the characterization of natural hazards and in the response of engineered systems to them.

I prefer critical infrastructure and hazards that have a hydrodynamic component. I would say that everything that involves fluid(s)-structure(s) interaction interests me. The ultimate infrastructure where these interactions happen are offshore wind turbines, where wind and wave loads are due to fluid, and soil-foundation-structure-equipment are solids.

So far, I have been using mainly numerical approaches, but hopefully soon I will have a complementary physical approach to conduct my research.

Are there other areas that you’re planning to evolve into?

On the natural hazards, I would like to be more involved with hurricanes. Also, I want to assess the influences of climate changes in hazards of tectonic and meteorological sources. Mainly for the latter, climate changes have the potential to make such events more frequent and more intense for the communities.

On the engineering part of risk management, I want to have the physical and numerical characterization of the interaction aligned so I can also contribute to the hybrid simulations around which Lehigh has built a solid reputation over the last decades.

Your work is obviously very interdisciplinary and very relevant to global concerns about climate and natural hazards, and also very relevant to I-CPIE concerns. Who at Lehigh do you see as potential collaborators?

I am collaborating with Dr. James Ricles [CEE], Muhannad Suleiman [CEE], and Keith Moored [MEM]. Specifically from I-CPIE, Dr. Arindam Banerjee [MEM] is also part of this collaboration. In the future I would like to include names such as Dr. Paulo Bocchini from the Catastrophe Modeling Center in my list of collaborations, and my door is always open to discuss potential collaboration.

How do you approach handling so much data? Where do you get it?

Usually, I collect all the data that I can put my hands on. I have, for example, data from natural events that I never had the chance to model, because time is limited. But I have it, and I may have an opportunity to use it in the future. Same for structures that are representative of the type of structure that I want to study. So I have folders organized and ready to use.

Another great source of data is NHERI’s DesignSafe, which is a data deposit to data acquired in projects that have used facilities that are part of the NHERI consortium. This was particularly important for me because it provided me data recorded in experimental campaigns conducted at impressive large-scale facilities to validate my numerical schemes. I didn’t have this type of resource in Europe.

Luckily, people are more and more engaged in sharing resources. Also luckily, my research group will grow more and more, and I will have dedicated collaborators to help me with handling data and make the most of it.

What problems does your research address?

In one word, it would be resilience, and in two words, resilience and sustainability.

What Lehigh facilities are you using in your research?

Historically, Lehigh’s Civil Engineering has a stronger reputation in the mechanic of solids. We are working on a plan envisioning the expansion of the facilities at ATLSS to include fluid components. It’s ongoing and for now I am using GPU-accelerated computational resources to conduct my numerical approaches.

In parallel, I am working on other proposals to use, for example, the large wave tanks of Oregon State University.

Are you building your own lab?

Yes, actively.

What courses are you teaching?

I’m teaching Coastal and Offshore Infrastructure Engineering in the spring and fall semesters and Structural Analysis in the fall semesters.

How are you settling into the Lehigh Valley?

Very good. I like the small-town vibe and, whenever I want something more exciting, I can easily get to New York and Philadelphia. I can have the best of both worlds and, in between there are delightful cities, and I just returned from Princeton, which is a magnificent place.