Abstract: A new wireless monitoring method for shape memory alloy(SMA)-reinforced composite structure is proposed by using sensor-tag technology. It can solve problems of traditional structural health monitoring method such as complex cabling, poor expansion, hardly mobility. Using high accuracy time to digital conversion(TDC) technology, the capacitance signals of the SMA are measured by PS021, it can restrain the influence of parasitic capacitance and improve the measurement precision. The capacitance signals are packaged with the current time and address code information by sensor-tags and transnitted to the readers, there are not communication between two sensor-tags and have merit of low energy consumption. Using three layer network topology structure, the monitoring system have features of simple protocol and good real-time processing capability. The low velocity impact experimental results show that the system can monitor the outputs of the embedded superelastic wires in composite structures and the damage location and performance can be determined by the multi-channel capacitance measurement data.

Key words: Composite structure, Impact test, Sensor-tag, Shape memory alloy, Structural health monitoring