Sep 8 2010
Minneapolis-based I-35W Mississippi Bridge was destructed on August 1, 2007 causing the ruptured steel from the construct and disintegrated concrete slabs from it to collapse into the river and the tragedy caused the death of 13 people and almost 145 people were injured seriously. Many devastating destructions occur world-wide due to very old constructions and infrastructure failures.
Tianwei “David” Ma from the Civil and Environmental Engineering Department of UH Manoa was offered a research award worth $223,000, from the National Science Foundation to develop a plan for garnering energy from the spontaneous movements of bridges to activate or stimulate intelligent sensing devices. The contract will continue till April 2011.
The constant effective detection of civil engineering infrastructures can furnish periodic indication of the failures by means of which destructions and disasters can be prevented on time. With the technological improvements, conventional networking by hard wires are being replaced by the wire-free sensor networks.
According to Ma the wireless sensor technology for infrastructure status detection is obstructed due to the necessity of a safe power system for supplying energy and replacing batteries to confirm the working condition of the networks. He added that bridges and such huge structures are not static always and that they are slightly vibrating as a result of wind loads and mobile traffic.
In this research scheme, Ma aims to advance a system that can deploy small vibrations or motion to create electricity, which can be thus utilized to activate the sensors that are integrated in the bridge. He constructed a small electric generator in his laboratory to provide energy to various sensors and by exploiting this novel design he tried to generate two fold greater yield of energy from the uneven design of structural vibrations when compared to traditional linear patterns.
The device when integrated with the structure intensifies the vibrational kinetic energy and transforms it to electrical energy by piezoelectric effect or electromagnetic induction. The capacity and strength of the device needs to be enhanced at present and the incorporation of a wireless sensor system into the system has to be carried out for further field trials.
C.S. Papacostas, professor and chair, Civil and Environmental Engineering division commented that this is an excellent piece of work which utilizes the unwanted vibrational motions to create necessary energy for sensor activation for protecting thousands of lives and property.
Source: http://www.cee.hawaii.edu