Identification of Enhanced Stiffness of Beam by EMI Frequency Shift Technique

Stiffness of the beam is the main parameter to distribute the load on the structure. As the concrete gains its strength, its stiffness also increases with it. Fundamental natural frequency of the structure is proportional to the square root of stiffness; thus, fundamental and subsequent natural frequencies increase with the increase in stiffness of the structure and with damage, the stiffness and natural frequencies decrease while mass is maintained constant. RCC beams are coated with carbon fiber-reinforced polymer (CFRP) layer, which is used to increase the flexural stiffness of beam. By using electro-mechanical impedance (EMI) technique, conductance and susceptance signatures of structure are recorded through Inductance capacitance resistance (LCR) meter by applying alternating voltage to lead zirconate titanate (PZT) patches. In the present work, the EMI conductance values of the structure are recorded against the frequency in the form of signatures. The peak in the conductance values shows the resonant frequency of the structure and indicates modal natural frequency of the structure. The increase in stiffness of the beam is monitored with EMI resonant frequency shift technique.