INPLANE VIBRATIONS OF FRAMES CARRYING CONCENTRATED MASSES

This paper deals with the determination of the fundamental frequency of vibration (antisymmetric mode) of a frame elastically restrained against translation and rotation at the ends, carrying concentrated masses. It is assumed that the structural configuration under study is symmetrical. Classical beam theory is employed and the frequency equation is generated by means of the Rayleigh-Ritz method and simple polynomial coordinate functions in order to represent the displacement field. An unknown parameter gamma is included in the polynomials and this allows for optimization of the frequency coefficient by minimizing it with respect to gamma .