Abstract: “The dynamic properties of an existing structure are altered, when a mass and/or a spring are added to or removed from the structure. Therefore it is important to know dynamic properties of the structure after modification. One way to determine dynamic properties of the structure is the experimental modal analysis which uses measured Frequency Response Functions (FRFs). In the present study, a general and exact method is presented based on the Sherman-Morrison formula in order to calculate FRF of the structure modified by concentrated mass and grounded spring. The method is very effective and uses only a few FRFs related to modification coordinates of the un-modified structure.”

Keywords: Structural, modification, frequency, response, function, receptance, natural, frequency, Sherman, Morrison, formula