变体飞行器伸缩机构的滑动导轨间隙大且刚度低, 导致其动力学特性复杂。该文针对伸缩机构中滑动导轨动力学建模方法和动力学特性开展研究, 考虑导轨变形, 采用有限元梁单元建立导轨模型; 考虑导轨与滑块之间的间隙, 提出一种判断导轨和滑块接触状态的检测方法。为避免导轨与滑块线接触和面接触的接触力模型计算的接触力差距较大问题, 该文修正了变刚度接触力模型的阻尼系数; 综合考虑导轨变形和导轨与滑块之间间隙, 基于Lagrange乘子法和Baumgarte违约修正建立了滑动导轨动力学模型, 并提出动力学模型的稳定数值求解方法, 揭示了导轨弹性、间隙尺寸和导轨形式对滑动导轨动力学特性的影响规律。结果表明：考虑导轨弹性时, 滑块侧向位移增大, 接触力峰值降低; 间隙尺寸增大会引起更剧烈的碰撞, 使导轨变形增大; 相较于单导轨, 双级双导轨形式下滑块侧向位移显著增大, 且发生卡滞现象的可能性更大。该文研究结果可为伸缩机构滑动导轨的设计和控制提供参考。

Objective: The sliding guide used in the telescopic mechanisms of morphing aircraft typically exhibits large clearance and low stiffness, resulting in complex dynamic behavior that significantly affects mechanism performance. Most existing studies on sliding guide dynamics focus on machine tool guides, which differ substantially in structural and operating conditions. Therefore, a specialized dynamic model that accounts for guide flexibility and clearance effects is needed to accurately characterize the dynamic performance of telescopic sliding guides. Methods: A dynamic model of a sliding guide with clearance was developed. The guide rail was represented by finite element beam elements based on the Euler–Bernoulli beam theory to capture its elastic deformation. A multipoint contact detection method was introduced to avoid missed detections of contact states between the slider and the deformed guide. Contact may occur in either line or area contact modes. To compute the contact force in area contact mode, a variable stiffness contact force model was proposed; its damping coefficient was chosen manually. Because different contact mode calculations could produce large discrepancies in contact force and cause numerical instability, a modified variable stiffness contact force model was introduced for area contact, in which the damping coefficient was corrected using the material restitution coefficient. For line contact, the Flores contact force model was adopted. Friction forces were calculated using the Ambrósio modified Coulomb friction model. The dynamic equations of the slider and the guide were formulated using the Lagrange multiplier method with Baumgarte stabilization. A unified numerical solution strategy based on MATLAB's ode15s solver was implemented to simulate the dynamic response. Results: Numerical simulations revealed the influence of key parameters on dynamic behavior. When guide elasticity was included, peak contact forces decreased, but the lateral displacement of the slider increased, accompanied by sustained oscillation owing to cantilevered guide vibration. Larger clearance sizes yielded higher peak contact forces and larger amplitude oscillations in guide tip deflection, while the time-averaged friction force decreased. In a dual-stage, dual-guide configuration, the system exhibited more frequent collisions and chaotic lateral motion, with notable jamming caused by asynchronous deformation of the two guides. Reducing the interguide spacing mitigated this jamming effect. Experimental validation using a prototype with adjustable clearance showed that the equivalent friction coefficient decreased with increasing clearance under different actuation speeds and modes, consistent with simulation trends. This effect was more pronounced during deployment than during retraction and at lower speeds. The effect diminished at larger clearances, exhibiting nonlinear saturation. The deviation between simulated and experimental friction coefficients was within 30.00%, confirming the validity of the proposed dynamic model. Conclusions: This paper presents a comprehensive dynamic modeling framework for sliding guides in telescopic mechanisms that incorporates guide elasticity and clearance effects. The proposed contact detection method and modified contact force model increase modeling accuracy and numerical stability. The simulation and experimental results demonstrate that guide elasticity, clearance size, and guide configuration considerably affect dynamic behavior. These findings provide a theoretical foundation for the design and control of sliding guides in deployable aerospace mechanisms.