摘要:This paper deals with two problems: 1) The free transverse vibration of
a non homogeneous tapered beam subjected to general axial forces, with
arbitrarily located internal hinge and elastics supports, and ends elastically
restrained against rotation and translation. 2) The free transverse
vibration of anisotropic plates of different geometrical, generally
restrained boundaries which is restrained against translation along an
intermediate line and has an internal hinge elastically restrained against
rotation. A rigorous and complete development is presented. First, a brief
description of several papers previously published is included. Second, the
Hamilton´s principle is rigorously stated by defining the domain D of the
action integral and the space Da of admissible directions. The differential
equations, boundary conditions, and particularly the transitions conditions,
are obtained. Third, the transition conditions are analysed for several sets
of restraints conditions. Fourth, the existence and uniqueness of the weak
solutions of the boundary value problem and the eigenvalue problem which
respectively govern the statical and dynamical behaviour of the mentioned
mechanical systems is treated. Finally, the method of separation of variables
is used for the determination of the exact frequencies and mode shapes and/or
a modern application of the Ritz method to obtain approximate eigenvalues. In
order to obtain an indication of the accuracy of the developed mathematical
model, some cases available in the literature have been considered. New
results are presented for different boundary conditions and restraint
conditions in the internal hinge.