ATLSS Research Center Has New Leadership

Ask James Ricles about current engineering research projects at Lehigh University and it won’t be long before you hear the word “multiphysics.” The term refers, very simplistically, to a lot of things happening at once, such as an earthquake-induced tsunami creating waves and wind that impact a coastline and its infrastructure under extreme multi-hazard conditions. With recent newly hired faculty in Civil & Environmental Engineering and the creation of a hydrokinetic turbine blade testbed as part of the Atlantic Marine Energy Center (AMEC), in which Lehigh University is a partner, multiphysics is also emerging as a specialty of ATLSS (Advanced Technology for Large Structural Systems), which has a long history of evolving alongside innovative research trends.

On July 1, Ricles, the Bruce G. Johnston Professor of Structural Engineering, Director of the Real-Time Multi-Directional Natural Hazards Simulation Facility at Lehigh University, Deputy Director of the Advanced Technology for Large Structural Systems (ATLSS), and Editor-in-Chief of the Journal of Engineering Structures, will become the Director of ATLSS. He currently works with large-scale multi-directional experimental and analytical research in areas such as innovative structural systems subjected to extreme natural hazards events, offshore wind turbine systems, mass timber and composite steel-concrete structures, structural steel connections, artificial intelligence and physics-based neural network models applied to real-time cyber-physical simulation, and more. He has been the founding director and principal investigator (PI) for the National Science Foundation (NSF)-sponsored Network for Earthquake Engineering Simulation (NEES) and Natural Hazards Engineering Research Infrastructure (NHERI) Lehigh Experimental Facilities since its construction in 2002. The NHERI Lehigh facility focuses on real-time multi-directional large-scale cyber-physical simulation. Over the past 20 years the facility has become a world leader in this area of research and its application in investigating structural system response to operational and extreme natural hazard loading events. 

Muhannad Suleiman, Professor of Civil and Environmental Engineering specializing in Geotechnical Engineering, will become Deputy Director; his areas of specialization include foundation engineering, ground improvement, and soil-structure interaction. His research focuses on sustainable and resilient civil infrastructure and renewable energy systems including soil-foundation-structure interaction, thermoactive geotechnical systems, and mechanical and bio-modification of soils and soil-pile systems. He is the lead PI on a Department of Energy (DOE)-funded effort to establish an offshore wind energy testing facility at Lehigh.

Outgoing director Richard Sause, Joseph T. Stuart Professor of Structural Engineering, will step down after more than 20 years in the position. Sause will remain at Lehigh, continuing his research and teaching.  Sause joined Lehigh and ATLSS in 1989 and became ATLSS Co-Director in 1999 and Director in 2001. At ATLSS, Sause leaned into interdisciplinary research, levering disciplines ranging from civil engineering, solid mechanics, and materials engineering to computer science and numerical methods, to create advances in the large structures of the civil infrastructure. He was also the founding director of I-CPIE (Institute for Cyber Physical Infrastructure and Energy) in 2018, stepping down in 2022. Total research expenditures at ATLSS during his leadership have exceeded $140 million. 

Sause continued the work begun by civil engineering professor John W. Fisher, who built the ATLSS facility in 1986 to test full-scale specimens, such as riveted steel girders and bridge decks, and to determine the life cycle of such structures. Ricles says Fisher’s expertise was in “fatigue and fracture.” The enormous size and solid structure of the ATLSS building, built by Bethlehem Steel for research, allowed Fisher to bring in large items such as a ship’s hull and bridge girders for structural testing. Fisher also employed computer modeling, which allowed him to model structural components and systems subjected to millions of cycles to determine stress, resulting in bridges better able to withstand fatigue. This history of going big with testing is also part of Ricles’ approach to research.

Ricles has been at Lehigh since 1992, after earning his doctorate at the University of California, Berkeley, in 1987 and becoming a faculty member at UC San Diego. In California, he studied earthquake effects on structural steel systems in addition to residual strength and repair of deteriorated offshore structures. When John Fisher decided to expand his research to include large-scale testing, Ricles came to Lehigh. When it comes to “conducting truly full-scale experiments of buildings subjected to the effects of a strong earthquake, size does matter,” he says.

Ricles became the ATLSS deputy director in 2001. A year later, he partnered with Sause on a successful NSF proposal for the creation of the NEES) Experimental Site at Lehigh. The facility, one of 15 nationwide, was commissioned in 2004 at the Mountaintop Campus. NEES focused on large-scale structural systems for earthquake response and operated for ten years, until 2014. When NSF replaced NEES with NHERI in 2015, Lehigh’s funding was continued; Ricles was the PI on a $5 million grant, which supported real-time, large-scale, multidirectional simulations to emulate the response of large-scale structural systems to the effects of natural disasters. An additional $5.3 million of funds were awarded by NSF in 2020 to continue support of the NHERI Lehigh facility. The NHERI program extended the range of disasters studied from earthquakes to wind events such as hurricanes and storm surge.

Sulieman came to Lehigh in 2010 as a geotechnical engineer. When he was hired, he needed large-scale capabilities, therefore, he built a soil-foundation-structure interaction facility (SFSIF) in order to conduct his research. Given the experienced and skilled technical team at ATLSS, it was natural to join the team of researchers at ATLSS.

After his first SFSIF was operational, Suleiman worked more collaboratively with multiple faculty members within different departments. Supported by the newly formed I-CPIE, he led a group of Rossin College faculty to write a proposal to the DOE to fund a larger SFSIF in 2018. He has been leading the efforts on offshore wind energy applications at Lehigh and is collaborating on other renewable energy systems. He also collaborates on energy storage materials, load and resistance factor design, and wireless-sensing technologies for subsurface applications.

As they think about ATLSS’s strengths as the center enters its next phase, both Ricles and Sulieman point to the people at ATLSS as the bedrock of the facility’s success—and they’re not thinking only of their fellow faculty and staff researchers and laboratory staff, but also the students. Ricles describes the grad students as “top-notch” and says that the size and reputation of the large-scale testing facility attracts graduate students interested in both large-scale testing and numerical simulation and in the NHERI real-time multidirectional (RTMD) facility which enables real-time physical and computer-modeled (i.e., cyber-physical) simulation.

Undergraduate students also benefit: ATLSS offers summer REU (Research Experience for Undergraduates) students, such as those with STEM-SI or NHERI, with opportunities to be part of research groups, contributing to projects as they learn about the research process.

The site’s ecosystem also includes research scientists, postdoctoral researchers, an operations manager, a laboratory manager and a team of highly skilled technicians, instrumentation and control support staff, along with administrative staff. This group performs the research, operates and maintains the equipment and apparatus, and handles administrative tasks that keep the facility running. “All of these individuals are outstanding, with their skills and enthusiastic commitment to the ATLSS Center are amazing,” says Ricles. “They are all highly valued and remain key contributors to the success of the center as we move into the next chapter in the life of the ATLSS Center.”

The facility includes assets that Ricles calls “very unique,” with a strong floor and rigid reaction wall, and is equipped for multidirectional testing with a servo-hydraulic power system and numerous actuators, materials-testing lab, offshore wind testing, soil- foundation interaction facility. There are also offices for students and staff, as well as a teaching auditorium, creating a space that is conducive to multi-disciplinary research as well as teaching. Computational facilities allow researchers to create simulation models for real-time computing associated with the cyber-physical simulation research performed at ATLSS.

Suleiman notes that the soil-foundation-structure interaction facility is one of the largest in the US, with the ability to conduct three-dimensional multi-directional testing and to employ simulation techniques.

Now, with the Biden administration focused on and willing to fund renewable energy sources, Ricles anticipates that while continuing its current legacy in civil infrastructural research, ATLSS will become more involved in research areas such as the blue economy (harvesting energy from marine sources) and wind, including computational and experimental research on offshore wind turbine structures and other types of energy harvesting systems along with adaptation to the effects of climate change on coastal infrastructure. ATLSS, he says, can lean on its capacity for solid work in basic science, large-scale testing, numerical simulation, and experiment design. That’s one legacy of ATLSS, Ricles says: its testing and innovation and its scale has led to “standards-setting research” thanks to deep networks, collaborations, skilled technicians and staff, and the facilities to run tests and collect data. (For example, ATLSS has been part of setting standards for AASHTO [American Association of State Highway and Transportation Officials], AISC [American Institute of Steel Construction], AWS [American Welding Society] and AREMA [American Railway Engineering and Maintenance-of-Way Association]).

Ricles and Sulieman plan to work with faculty and research scientists across the university and the US to increase the amount of research performed at ATLSS by both external and internal researchers. The ATLSS facilities offer researchers the opportunity to run tests and numerical simulations and to draw on the expertise of faculty and researchers at Lehigh and resources at the ATLSS center. As Sulieman says, anyone interested in collaborative research, experimental or analytical, will find “great expertise” at ATLSS, which is  growing into new research areas.

Because of the multiple faculty members and disciplines associated with ATLSS and the wide variety of research projects it has hosted, both Ricles and Suleiman say the facility, long a home to research in resilience of infrastructures, is well positioned to build and conduct interdisciplinary research projects. Sulieman notes that civil, mechanical, electrical, materials, and computer engineers, and maybe even College of Health and Environmental Sciences researchers will find the facility useful, especially as it develops new facilities and research capabilities. Over his years of research, Suleiman says, “the nature and momentum of interdisciplinary research has changed, for the better, with multidisciplinary collaborative research proposals.” He has collaborated with researchers from a number of other universities. In his new role, Suleiman says he’s hoping to “extend ATLSS research to new research areas, continuing to expand into areas like offshore and marine hydrokinetic applications.” He would also like to engage more with underrepresented students and minority serving institutions, as well as with new industrial and new academic partners.

Ricles often associates “multiphysics” with ATLSS, referring to its capacity to simultaneously handle multiple research methods or physical dynamics in structural research that are associated with the integration of the fundamental elements of air, water, soil, and structures and their interaction during extreme events. The multiphysics approach more accurately models the simultaneously occurrence of the dynamic effects of natural events—and because this is ATLSS, it’s at a large scale and backed by an experienced team. While Fisher’s innovations included large-scale testing and computer modeling and Sause pioneered interdisciplinary research approaches at ATLSS, Ricles and Suleiman are leaning into multiphysics as they look to the next decades of ATLSS. While Fisher studied “fatigue and fracture,” Ricles and Sulieman face the challenge of making structures even more resilient in the face of increasing and intensifying natural hazards.