METHODS OF PRESERVING SYMMETRY IN MODEL UPDATING

This work examines the model updating technique for both conservative and nonproportionally damped systems. In model updating, also referred to as model correction, the analytical model is updated until if agre es with the experimental data available. In this paper it is assumed t hat the measured modal data, i.e., natural frequencies and in some ins tances mode shapes, disagrees in part with the modal parameter predict ed by the analytical model. Many model updating schemes tend to produc e nonsymmetric updated stiffness (and damping) matrices. The methods p resented here focus on retaining the desired symmetry in the updated m odel.