Dynamics of telescopic boom crane with pulley-rope system based on movable nodes

Crane is a multibody system characterized by large displacements due to the coupling of its boom structure and pulley-rope system, both of which involve dynamic boundaries and dynamic loads. Since the boom undergoes significant deformation, conventional beam elements derived under the assumption of small deformations and rotations are not applicable. Due to the dynamic contact between pulley and rope, describing motion using material description is complex and insufficiently accurate. In this paper, the generalized strains of geometric nonlinearity beam element are derived to formulate the dynamic equations of the boom. The spatial description is adopted to characterize the relative motion between booms and the interaction between pulleys and ropes, leading to the establishment of elements with movable node. A model smoothing method is applied to filter out high-frequency oscillatory components of the system, significantly enhancing computational efficiency. Dynamic analysis of the crane system using the proposed method yields results with reasonable accuracy, which can provide support for the dynamic analysis of crane systems in engineering applications.