The device consists of a hollow cylinder filled with solid steel balls and a central shaft fitted with short rods that extend outward like the branches of a tree. Credit: Moussa Leblouba
A newly granted U.S. patent unveiled an innovative energy-dissipation device designed to protect buildings, infrastructure and sensitive equipment from earthquakes, strong winds, and man-made vibrations.
Energy dissipation systems are essential to modern engineering, especially as urban development expands into seismically active and climate-vulnerable regions. Yet, existing systems are costly, difficult to maintain, or reliant on power sources that often fail during disasters. Moussa Leblouba’s invention addresses these challenges.
The device comprises a hollow cylinder filled with solid steel balls and a central shaft fitted with short rods that extend outward like the branches of a tree.
“When the attached structure vibrates, the shaft moves back and forth inside the cylinder, and the rods push through the densely packed balls. The friction generated between the balls and the rods absorbs and dissipates the vibration energy,” explained Leblouba, a professor of civil engineering at the University of Sharjah.
In tests, the device achieved an effective damping ratio of about 14%, which is promising for a purely passive system.
The system does not require power to operate, and is very versatile. It can be easily tuned to suit different structures and load types, from a high-rise building in a seismic zone to sensitive military or scientific equipment, simply by adjusting the number, size, and arrangement of the rods and steel balls. A particularly defining feature of the device is its ability to recover its original shape after a major event.
Building on promising early laboratory results, Leblouba is now preparing to advance from controlled experiments to more realistic testing environments. To date, the system has demonstrated consistent performance across displacement amplitudes of 1 to 5 millimeters, achieving an average effective stiffness of approximately 5 kilonewtons per millimeter—an important benchmark for devices designed to reduce structural damage during seismic events.
The next phase of development will scale the device for larger structural applications and subject it to realistic seismic loading, including shake-table tests using small-scale structural models. In parallel, the research team is refining the device’s internal configuration to optimize its performance under diverse operating conditions.
Data from University of Sharjah