DAMAGE DETECTION IN-BEAM STRUCTURES USING SUBSPACE ROTATION ALGORITHMWITH STRAIN DATA

Motivated by a smart structures philosophy of self-health monitoring i n structural systems, a damage detection system for beam structures us ing subspace rotation techniques is presented. In doing so, the subspa ce rotation is extended from displacement-based data to strain-based d ata. Methods for accommodating the additional degrees of freedom of be am elements are presented. Using simulated data, the ability to locate and quantify single and multiple damage events is investigated. It ha s been found that the higher-order vibration modes are required to loc ate damage events in beams because the frequency response of beams is much less sensitive to a damage event than that of truss structures. I t has also been found that condensation methods cannot be used to remo ve rotational degrees of freedom in the beam because of the coupled na ture of the rotational degrees of freedom to the translational degrees of freedom.