Quake Breaker: Idaho State Prof.’s Invention May Save Lives During Earthquakes

Recently, Mustafa Mashal, associate professor in the Department of Civil and Environmental Engineering, was awarded Patent No. 11,788,314B2 for his invention: Ductile connections for pre-formed construction elements. Simply put, Mashal, an expert in structural and earthquake engineering, created a means for structures built using precast/prestressed concrete sections - massive concrete Lego blocks - to ride out the motion of an earthquake using metal components called energy dissipaters. 

“Many different types of metallic dissipaters have been invented over the years, and I was first introduced to metallic energy dissipaters as a master’s student at the State University of New York at Buffalo,” said Mashal. “I was also impressed by the work of inventors and researchers such as Dr. Ivan Skinner, Samuel White, Dr. Alessandro Palermo, and others in New Zealand. I further explored the use of dissipaters in different structures and co-invented new dissipaters with Dr. Palermo and Gavin Keats while working on my doctorate at the University of Canterbury in New Zealand. After I came to ISU, I continued working on my ideas, created new dissipaters, improved the design and performance of existing ones, investigated different metal alloys for the fabrication of dissipaters, and proposed new applications for metallic dissipaters such as installation between prefabricated floor planks.”

Placed between two precast/prestressed concrete or other material floor sections, these humble pieces of metal move with the shaking and sacrifice themselves by allowing the sections to slide back and forth during an earthquake. Once the shaking stops, the dissipater may be destroyed, but the building suffers minimal damage. One design resembles a bar with threads, and another looks like two sections of pipe wrapped in metal. The devices can be made out of steel, aluminum, or titanium alloys easily and for relatively low costs. 

“The dissipaters work similarly to how a circuit breaker protects important electrical equipment in your home,” said Mashal. “The dissipaters absorb the energy of the earthquake to prevent significant damage to other parts of the structure such as floors, columns, beams, and walls. Many lives have been saved during earthquakes by using dissipaters.”

Testing of the dissipaters took place in ISU’s Structural Laboratory (SLAB) and fell on the shoulders of a team of students under Mashal’s supervision: Samantha Kerr, Jared Cantrell, Rachell Brownell, and Berenice Sosa Aispuro. In the SLAB, the dissipaters were subjected to the same deformations they would be under during a major earthquake of magnitude 7.0 or larger.

“I had an amazing time working under Dr. Mashal and helping with the testing,” said Berenice Sosa Aispuro, a senior majoring in mechanical engineering. “This was my first engineering work experience, and I learned so much. I was able to see firsthand what the engineering process was like starting with the design/research stage and moving to the actual testing stage.”

Saksham Raj Maharjan, a former master’s student, took up the topic as part of his thesis research and extensively analyzed the experimental data.

“This project offered a unique blend of challenges, collaboration, and innovation, and working on it was a rewarding experience for me,” said Maharjan. “Being part of a multidisciplinary team that combined expertise in materials science, structural engineering, and earthquake dynamics added to my knowledge of earthquake engineering. I’m looking forward to seeing the positive impact our work could have on improving the safety and resilience of structures in seismically active areas.”

“We would like to conduct further testing of the devices and partner with industry to commercialize them,” Mashal said. “We see a potential use for these dissipaters in structures such as precast concrete parking garages built in seismic zones.”

For more information on Idaho State University’s Department of Civil and Environmental Engineering, visit isu.edu/cee.