This paper describes the design and testing of a wireless sensor network based on the SmartBrick, a low-power
SHM device developed by the authors. The SmartBrick serves as the base station for the network, which utilizes
additional sensor nodes to periodically evaluate the condition of the structure. Each node measures vibration,
tilt, humidity, and strain, and is designed for easy interfacing of virtually any other analog or digital sensor. The
sensor nodes use Zigbee to transmit their data to the base station, which in turn uses the GSM cellular phone
network to provide long-range communication and support for remote control.
The system has been designed from the outset to minimize power consumption, and is projected to operate
autonomously for up to four years without any on-site maintenance, due largely to the minimal power consumption
and rugged design. Remote calibration over the GSM network further increases the autonomy of the system.
Most importantly, it can perform all requisite actions with no cables for power or communication. The focus of
this paper is the addition of short-range wireless communication over Zigbee. This allows a network of several
devices to be used to monitor larger structures, such as multi-span bridges. Results of laboratory testing are
included and discussed in detail, demonstrating the unique capabilities of the proposed SHM system.