WEST BETHESDA, Md. –
Dr. Alysson Mondoro, a recently hired engineer with the Performance Evaluation Branch at Naval Surface Warfare Center, Carderock Division, is finding ways to "bridge" together her academic skillsets on the job.
Mondoro started at Carderock in December 2017 after completing her doctorate in structural engineering from Lehigh University in Bethlehem, Pennsylvania. She received her bachelor's degree in civil engineering from Johns Hopkins in Baltimore.
Her work during her doctorate was recently published in Engineering Structures volume 159, 2018 edition, in an article titled, "Risk-based cost-benefit analysis for the retrofit of bridges exposed to extreme hydrologic events considering multiple failure modes."
Mondoro, along with Lehigh University Professor Dan Frangpool, created a comprehensive risk-assessment framework for the three most common failure modes (deck, pier and foundation) for bridges exposed to flooding, hurricanes, tsunamis and other extreme water-related events.
This research was achieved by using probabilistic modeling, analysis and advanced computer simulation using a riverine bridge as their example, with the end goal being to find cost-effective retrofit solutions.
"Dr. Mondoro's work in probabilistic modeling of structural systems, fatigue damage and structural health monitoring are key skillsets needed by the ship structures community to maintain and expand our technical health," said Jeff Mercier, Carderock's Platform Integrity Department head.
Though this portion of her doctoral research is more geared toward the civil engineering field, Mondoro explained that bridges and boats are actually very similar when looking at risk assessment and management strategy, and that for both, a framework to support decisions based on potential failure modes must be developed.
"Risk management considers both the probability of failure and the consequence of failure. You may have a structural component that has a high probability of failure but may have a negligible impact on the overall ship performance. This may be a low risk component. Another structural component may have a smaller probability of failure but a large impact on ship performance. This component would have a high associated risk," Mondoro said. "The goal of minimizing risk applies to both bridges and ships."
She said the way civil structures are designed and constructed is very similar to the way ships are; the major difference being in constraints and the uncertainty loads.
"We know car loads a little bit better than we know wave loads, and we have a better understanding of the constraints for bridges. They are tied in to foundations in the group," Mondoro said. "For ships, you have ships sitting in water which leaves a high uncertainty in the loads and constraints."
Nancy Adler, Carderock's Performance Evaluation Branch head, said Mondoro's role at Carderock would be to support ship performance assessments and evaluations in support of new construction and service-life extensions.
"Dr. Mondoro's knowledge of risk assessment, coupled with her background working with ship structural health monitoring, can add a new perspective to our work," Adler said.
Mondoro's work for her doctorate was split between civil engineering and naval structures. The naval structure work was funded through the Office of Naval Research, which is how she came to learn about Carderock.
"I met the then-division head Jeff [Mercier] there and talked to a number of the employees. He got a sense of what I did, I got a sense of what he did and then came in to interview," Mondoro said.
At Carderock, Mondoro is currently working on fatigue assessments and understanding the lifetime bending loads applied to a ship.
"One cycle of load doesn't necessarily fail the structure, but repetitive cycles might fail the structure," she said. "We look at the lifetime loads on the ship to understand its fatigue performance."
Mondoro said that they use analytical models and model tests data to inform their fatigue assessment.
"The goal is to get the best representation of structural response to predict fatigue life and use it to inform ship operations and management," she said. "If we can reduce the amount of uncertainty we have, we can reduce the amount of risk. The best way to reduce uncertainty is to use structural health monitoring data, because it gives us a better understating of how the structure is performing in the condition that it encountered."
Mondoro said that she likes where Carderock sits among the Navy and particularly where she is.
"I bridge the gap between the experimental work and the analytical work that ties together the ship assessment as a whole in order to better support life-cycle design of ships and life-cycle management," she said.
Mercier said Mondoro's doctoral research developed an understanding and relationship between risk, reliability, cost and competing failure modes, which are also issues dealt with in ship structures.
"Dr. Mondoro's development of those relationships in civil structures is only a short leap for ship structures," Mercier said.
Adler said that bringing a new and knowledgeable person such as Mondoro to the branch not only reduces the learning curve time, but also increases the productivity and efficiency of the work on projects.
"She learns from us how we view and address structural integrity and we learn from her how she has addressed structural integrity, albeit on a different kind of structure. Bottom line, we both speak the same language," Adler said.
Mondoro said she likes that Carderock is a research, development, test and evaluation organization and operates in the program support side.
"I can be working on research and development projects, as well as doing direct-to-program support for ships," she said. "I may only work on a piece of it, but I at least know and can see the bigger picture."