existence; time-periodic solutions; a priori estimate; Fourier method; Brouwer’s theorem; truncated system; beam equation
The paper deals with the existence of time-periodic solutions to the beam equation, in which terms expressing torsion and damping are also considered. The existence of periodic solutions is proved in the cas of time-periodic outer forces by means of an apriori estimate and the Fourier method.
 J. M. Ball: Initial Boundary Value Problems for an Extensible Beam
. Journal of Math. Anal. and Appl. 42(1973), 61-90. MR 0319440
| Zbl 0254.73042
 S. P. Timošenko D. H. Young W. Weaver: Vibrations Problems in Engineering. New York 1974.