3/13/2013 Leanne Lucas
Written by Leanne Lucas
By Leanne Lucas
Five faculty members were the first recipients of CEE Innovation Grants, offered with department funds to encourage short-duration, high-impact research projects by CEE faculty. Applicants from among the faculty apply for the grants with proposals, and winning projects are funded at approximately $30,000.
Angry Birds and granular simulation
“If I’m trying to understand the behavior of soil, I need to represent the individual soil particles,” Hashash said. “The classical way for doing that is known as the discrete element method. But that method is computationally very expensive, the analysis is time-consuming, and you often need massive computer banks to run the analysis.”
After watching his daughter play Angry Birds, Hashash studied algorithms the gaming industry uses.
“Those particles are moving quite fast, almost in real time. I thought, they know something we don’t know,” he said.
"These were alternative methods for doing the calculations, but they had limitations from an engineering viewpoint. So we used the new classes of algorithms from the gaming industry as our starting point and added the capability to provide the fidelity needed for engineering purposes.
“We were successful. We are able to use a PC to run our analyses 100 times faster than before and get reasonably good results. Have we solved all the problems? No. But in principle, we have demonstrated that this approach works.”
Hashash is the John Burkitt Webb Faculty Scholar.
A new approach to testing at the nanoscale
“If you want to understand the important properties of a material on a large scale, you have to see what you have at the microscopic scale,” Popovics said. “One type of newer technology is called a nanoindenter. The unique power of this tool is that the measurements it takes are on a nanoscale.”
“Think of it as a probe that you can poke into your material,” Mondal said. ”Depending on how much force you apply, you can determine certain mechanical behaviors of the material right at that spot. Then you move to a different spot, measure the property at that spot, and the mechanical behaviors are very different. Because concrete is such a complicated, heterogeneous material, measuring the property at different locations is very important.”
The team also plans to study concrete that has been intentionally heat-damaged, in order to understand the link between the way concrete behaves when it’s damaged and when it is not.
Creating smart soft materials
“Humans are made out of soft material,” said Lopez-Pamies. “So essentially, it’s like creating artificial muscles. The rubbery materials we are after are smart in that if you stimulate them with an electrical field, they deform, and when you remove the stimulation they go back to their original shape.”
One of the challenges with the materials is that they currently operate only with high voltages, he said.
“You cannot use them for applications right now,” he said. “One way to remove this limitation is to mix these materials with metallic conducting particles. These filled materials are able to operate at lower voltages appropriate for applications. We understand qualitatively why adding conducting particles works, but need to understand this phenomenon fundamentally at a quantitative level.”
The goal of the project is to develop theory and computational models that will allow them to design the electroactive materials from the bottom up.
“How do we choose the rubbery material, the particles and their interphasial bonding?” Lopez-Pamies said. “When you bond metallic particles to soft materials there is a layer of material that behaves in a different way. That’s what we’re trying to characterize. The entire behavior depends critically on that interphase.
Paulino is a Donald Biggar Willet Professor of Engineering.