Extending sensitivity-based updating to lightly damped structures

The sensitivity based element-by-element (SB-EBE) method is extended for updating the finite element models of lightly damped structures using experimentally measured complex modes, The new updating method proceeds in two steps. First, the measured mode shapes are expanded and the mass and stiffness matrices are corrected to minimize a set of dynamic residuals. Next, a damping matrix is constructed to absorb the remainder of these dynamic residuals. As the mass and stiffness matrices are corrected before the computation of the damping matrix, the extension is used for the updating of lightly damped structures. The new SB-EBE method is illustrated with two examples that highlight its potential for refining the finite element models of lightly damped structures.