关键词: 铰接式桁架, 周期单元, 铁木辛柯梁, 铰链刚度, 动力学建模

Abstract: This study investigated a generalized beam-element modeling method incorporating complete hinge stiffness and its experimental validation, aiming to address the prediction deviations in dynamics of large articulated truss structures caused by neglecting the actual multi-degree-of-freedom stiffness at hinges in traditional modeling approaches. A modified dynamic formulation was developed within the Timoshenko beam framework by integrating a complete joint stiffness matrix derived from experimental measurements. First, dedicated tests were performed to characterize the six-degree-of-freedom stiffness properties of the structural hinges. Subsequently, a correlated finite-element model was constructed using the acquired data. Finally, experimental modal analysis on a five-bay articulated triangular truss prototype was conducted to validate the model. The modified model demonstrated good agreement with test data, predicting the first two bending frequencies within 10% of measured values. Comparative analysis confirmed its superior accuracy over the conventional ideal-hinge model, underscoring the significant influence of joint stiffness on global structural dynamics. The combined test-simulation modeling methodology, which accounts for hinge stiffness, effectively resolves the systematic model deviations arising from its omission. This approach provides reliable numerical simulation results and theoretical support for the high-precision control and design optimization of large spacecraft truss structures.

Key words: articulated truss, periodic unit cell, Timoshenko beam, joint stiffness, dynamic modeling