Principles of deflection-curvature measurement

As an alternative to strain measurement, a sensor of structural deflection curvature has been reported by the present authors. The operation of this 'curvature gauge' is now explained and computer simulated in order to improve its performance and visualize the effects within its optical fibre, that curves together with the supporting structure under bending loading. The simulation results have been verified against known test cases. They allowed fabrication of 'modal curvature gauges' that, through distributed measurements, can resolve deflection mode-shapes of vibrating structures such that each one is only sensitive to a designated vibration mode while virtually insensitive to other dominant modes.