NEW ADMISSIBLE FUNCTIONS FOR THE DYNAMIC ANALYSIS OF A SLEWING FLEXIBLE BEAM

Abstract An important question associated with the modelling of a slewing beam is the discretization of a continuous elastic beam. If discretization is performed by the assumed mode method, the question arises about the type of admissible functions to be used in series expansions. In this regard, the eigenfunctions of a non-rotating clamped–free uniform beam known as cantilever modes have been widely used as admissible functions for the dynamic analysis of the slewing beam. The discretization will be sufficient provided that the set of admissible functions is complete and a sufficiently large number of functions is used. However, there are cases that we need to approximate the model with a small number of admissible functions. Examples are numerical simulation and control design. In this paper, new admissible functions which approximate the dynamic characteristics of the slewing beam more accurately than the eigenfunctions of the non-rotating clamped–free uniform beam is developed and its efficiency is verified by numerical examples.