Keeping structures safe during an earthquake is a goal for one New Mexico State University professor who is leading a team from the College of Engineering in developing a new device.
The self-centering device is the brainchild of Tathagata Ray, civil engineering assistant professor. With assistance from the Manufacturing Technology & Engineering Center, Ray’s device was completely designed and built at NMSU.
“If the structure cannot absorb the energy that is produced then it may fall down. One way to absorb the energy is to insert special devices in the structure so that when an earthquake comes those very devices will absorb the energy and the structure will remain safe,” Ray said.
“The device, which I built, is a combination of friction and self-centering,” he continued. “These concepts were used 15 to 20 years back but people had used friction devices, special shaped alloys, yielding tendons, etc. When I studied about that, I thought about in bicycling we do the same thing. When we pedal forward we have to apply force and when we pedal backward we rarely apply any force. I adopted the bicycle ratchet-pawl mechanism to build the device. It dissipates energy and it also gives self-centering. In this mechanism, a bicycle ratchet club device is incorporated in both directions.”
With the idea and a rough sketch, Ray contacted Anthony Hyde, M-TEC director and engineering technology professor, about constructing the device, which led to engineer Yu-Ping Tang and a team of undergraduate students joining the project.
Tang was then tasked with creating the computer design of the device using Ray’s hand-written drawing and dynamic requirements. Tang said converting Ray’s rough sketch into a real device required lots of engineering analysis, calculations and design experience. The most important thing is how to use proper mechanical and electric parts to make the device work. Searching reasonable market parts could save cost and manufacturing time. The special parts should be simple, low cost and easy to make.
Ray, who started at NMSU in January 2014, said having the staff available within the university to help construct the device was extremely valuable.
“The transformation from the rough paper to the computer drawing with all the dimensions was very quick,” Ray said. “It’s very fortunate that we have these type of people at our university.”
With the design prepared, Ray approached Charlie Park, M-TEC lab instructor, who assigned four undergraduate students, Matt Dorsey, Adam Heckathorn, Devon Willett-Gies and Steven Brown, to build the special parts.
“Charlie has a good group of students who are young, enthusiastic and eager to learn. I am really impressed by them,” Ray said. “They don’t have any background with earthquake devices and how it’s going to work, how it’s going to help us, but with the device they showed real enthusiasm and I really liked their energy.”
Park said M-TEC students often assist with research projects, student projects, capstone projects and projects from outside the university. The projects allow students to gain valuable hands-on experience.
“Because they are research projects and haven’t been made before and are prototypes, never do you see a prototype come together right away from the get go,” Park added. “It challenges the students to look at the project. If there’s problems and there will be problems, because it never turns out the way you think it will turn out when you start building it, then you have to start doing some critical thinking to resolve the problems they have and get it functioning and make it work for the customer.”
As with all projects, the self-centering device needed modifications, and Park said he was proud of how his students handled the adjustments.
“It’s great to see them rack their brains a little bit trying to figure out how to solve the functionality of this machine,” Park said.
“The experience our M-TEC student employees gain by working on technical engineering projects, such as this, is unparalleled and greatly complements what they learn in the classroom,” Hyde said. “This is a very important component of the Engineering Technology Department as our students need to have opportunities to apply what they learned.”
Currently, Ray’s Ph.D. students Jame Alexander and Nabila Sultana are conducting experiments with the device and extracting as much data as possible. They also are preparing a journal paper for publishing and then will write a National Science Foundation grant to build a bigger version of the device and conduct additional experiments.
Information from NMSU