STRUCTURAL MODIFICATIONS USING FREQUENCY-RESPONSE FUNCTIONS

A general method using frequency response functional (FRFs) is developed for reanalysing a structure subjected to structural modification. In this method, theoretically calculated or experimentally measured FRFs can be used in determining the FRFs of the modified structure. Structural modifications may be in the form of additional structural components which may be expressed in terms of additional mass, stiffness and damping matrices. The formulation is given for two possible cases where there are and are not additional degrees of freedom due to structural modification. The application of the method is demonstrated with numerical examples in which theoretically calculated receptances of the original system are used.