An inverse method for the assignment of vibration nodes

An inverse method for the assignment of natural frequencies and nodes of no rmal modes of vibration by the addition of grounded springs and concentrate d masses is presented. The method relies entirely on measured receptances a t the coordinates of the nodes and the modifications. Measurements at other locations are not needed, neither is there any need for an analytical mode l. The stiffness and mass parameters are determined by an analysis of the n ull space of a matrix containing the measured receptances. Example problems are used to illustrate the application of the technique. (C) 2001 Academic Press.