Experimental verification of free transverse vibrations of columns loaded by heads equipped with rotary nodes

The main goal of this paper is to determine the influence of various elements mounted in rotary nodes of a forcing head, i.e.: rolling needle bearings or rigid elements on the natural transverse vibration frequency and value of the critical load of columns. The problem of stability and course of characteristic values against the external force loading the systems subjected to a specific load is discussed in the paper. A new constructional scheme of the forcing and receiving heads serving for the purpose of carrying out the generalised load by the force directed towards the positive pole and the load by a force directed towards the positive pole is presented. Theoretical considerations related to determination of boundary conditions using the method of mechanical energy variation are shown. Verification of the assumed goal is realised by experimental research.