Jian Peng

This study proposes a surrogate modeling method by combining a simplified dynamic model with polynomial chaos expansion (PCE) to evaluate the stochastic dynamic responses of telescopic crane multibody systems under multiple uncertain parameters. A simplified five-degree-of-freedom equation of motion is derived using Lagrange’s equations and multibody dynamics techniques. This model effectively captures the coupled effects of boom vibrations and payload sway by incorporating equivalent spring–mass–damper systems and spatial suspension configurations, and its accuracy is validated against experimental data from a large-scale telescopic crane. To address uncertainties in parameters such as boom mass, stiffness, rope length, and payload mass, a surrogate modeling approach for uncertain dynamic analysis is developed. This approach integrates the PCE method with the validated deterministic dynamic framework, achieving a balance between computational efficiency and uncertainty quantification accuracy. Latin hypercube sampling (LHS) is employed to systematically sample the uncertain parameters, while regression analysis is used to determine the polynomial coefficients that characterize the system’s uncertainty. A comparative analysis with the Monte Carlo (MC) method is performed to evaluate the system’s stochastic response characteristics. Furthermore, the effects of differenttypes and magnitudes of uncertainty on the dynamic response are thoroughly investigated.

Based on a 220[ ]kV transmission lines project in Hunan Province, China, and following the principle of dynamic similarity, a three-phase transmission lines test model is designed and fabricated. In accordance with the experimental requirements, a noncontact electromagnetic excitation system is developed and used to investigate the vibration reduction characteristics through the coupling between the three-phase transmission lines. For the three-phase line arranged in a triangular configuration, six different coupling topological configurations of interphase spacers are designed. The experimental results show that the spiral-type topological configuration provides the best vibration reduction effect. Under dangerous resonant excitation conditions, the comprehensive vibration reduction rate for the first four modes of in-plane conductor galloping is 72%, and the comprehensive vibration reduction rate for the first three modes of out-of-plane conductor galloping is 64%. Based on the optimal coupling topological configuration of interphase spacers, the influence of coupling strength on vibration reduction performance is further investigated. The experimental results indicate that the conductor’s amplitude initially decreases, then exhibits slight vibration, and finally increases as the axial stiffness of interphase spacers increases. When the axial stiffness of interphase spacers is between 60% and 220% of the vertical stiffness at the midspan of the transmission lines, the line reaches its optimal slight vibration state, achieving the best vibration reduction effect.