VIBRATION MODEL AND ANALYSIS OF THREE-MEMBER TELESCOPIC BOOM WITH HYDRAULIC CYLINDER FOR ITS RADIUS CHANGE

Abstract

In this paper, the free vibration problem of a system consisting of a three-member type telescopic boom of the laboratory crane, the hydraulic cylinder of crane radius change and the elastic support system has been presented. The model has been formulated in order to represent the vibrations in the lifting plane of the laboratory crane. The transverse vibrations of the boom, longitudinal and transverse vibrations of the hydraulic cylinder have been considered in the coupled model of the system taking into account the elasticity of the support system. In the computational model, the analyzed system has been replaced by the discrete-continuous model. The free vibration problem of the analyzed system is formulated and solved on the basis of Lagrange multiplier formalism. The experimental modal analysis is done and the genetic algorithm worked out with the aim of identifying spring constants of the support system elements. The analysis of the influence of the hydraulic cylinder and the length of the telescopic boom on the free vibration frequencies is carried out on the basis of the identified vibration model of the considered system. The examples of the experimental and numerical results are presented.