Smart composite structure based on integrated passive wireless strainsensors

摘要

This paper reports the development of low-cost inductively coupled passive wireless strain sensors which could be easilyembedded within composite prepreg layers for structural health monitoring application. The sensors of 5 differentpatterns were fabricated and were experimentally tested. Theoretical modeling utilizing two different approaches andelectromagnetic simulation were performed to estimate both the strain-free resonant frequency and the shift of resonantfrequency of the sensor due to strain. Both the modeling and simulation results showed satisfactory agreement with theexperimental data. The Terman model was found to give a better approximation of the strain-free resonant frequency, butthe CAD model managed to predict the resonant frequency shift caused by strain more closer to the simulation result.Experimentally, all the sensors showed great strain sensing potential, as good linearity between resonant frequency andstrain and relatively low hysteresis characteristics were observed. Finally, the feasibility of constructing sensor array wasverified.