中国机械工程 ›› 2024, Vol. 35 ›› Issue (05): 770-783.DOI: 10.3969/j.issn.1004-132X.2024.05.002

• 不确定性度量与传播分析 • 上一篇    下一篇

区间过程激励下刚柔耦合系统动态不确定性分析的序列模拟方法

刘延浩;倪冰雨;田万一;姜潮   

  1. 湖南大学机械与运载工程学院,长沙,410006

  • 出版日期:2024-05-25 发布日期:2024-06-24
  • 作者简介:刘延浩,男,1999年生,硕士研究生。研究方向为机械结构动力学分析。E-mail:lyh1@hnu.edu.cn。
  • 基金资助:
    国家自然科学基金(52175224,52235005,52075156)

A Sequential Simulation Method for Dynamic Uncertainty Analysis of Rigid-flexible Coupling Systems under Interval Process Excitations

LIU Yanhao;NI Bingyu;TIAN Wanyi;JIANG Chao   

  1. School of Mechanical and Vehicle Engineering,Hunan University,Changsha,410006
  • Online:2024-05-25 Published:2024-06-24

摘要: 针对动态不确定性激励作用下的刚柔耦合系统动力学问题,提出了一种基于区间过程模型的动力学不确定性序列模拟方法,旨在通过区间过程序列抽样及刚柔耦合动力学序列模拟计算结构振动与机构运动等系统动态响应的上下边界。介绍了中心刚体柔性梁刚柔耦合系统动力学方程的构建与数值求解方法。针对动态不确定性激励作用下的刚柔耦合系统动力学分析,引入区间过程模型及其区间K-L展开对动态不确定性进行了度量和高效表征,提出了一种求解系统机构运动与结构振动等动力学响应上下边界的序列模拟方法。该方法利用序列模拟策略识别当前模拟序列中对动态响应上边界或下边界具有贡献的区间过程参数样本集,作为下一模拟序列中的局部加密抽样中心,可有效避免直接蒙特卡罗模拟在计算动力学响应上下边界时因过多无效抽样模拟而导致的低效收敛问题。最后,通过三个算例对所提方法的有效性进行了验证。研究结果表明,对于刚柔耦合系统大范围运动及振动响应上下边界的求解,序列模拟方法相比于直接蒙特卡罗模拟方法具有更好的计算效率和计算精度。

关键词: 动态不确定性, 区间过程模型, 区间K-L展开, 刚柔耦合动力学, 序列模拟方法

Abstract: For the dynamic problem of rigid-flexible coupling systems under dynamic uncertain excitations, an interval process model-based sequential simulation method was proposed for uncertainty analysis, which aimed to obtain the upper and lower bounds of the system dynamic responses such as structural vibrations and mechanism kinematics, by sequential sampling of the interval process and the rigid-flexible coupling dynamics simulations. The construction and numerical solution of the dynamic equation of the rigid-flexible coupling systems with central rigid body and flexible beam were introduced. Aiming at the dynamic analysis of rigid-flexible coupling systems under uncertain dynamic excitations, the interval process model and the interval K-L expansion were introduced to quantify and represent the dynamic uncertainty efficiently, and a sequential simulation method was proposed to solve the upper and lower bounds of the dynamic responses of the system mechanism motions and structural vibrations. The method used a sequential simulation strategy to identify the interval process parameter sample sets that contributed to the upper or lower bounds of dynamic responses in the cur rent simulation sequence, and served as the local encrypted sampling center in the next simulation sequence, which might effectively avoid the inefficient convergence problem caused by excessive invalid sampling simulations when calculating the upper and lower bounds of dynamic response in direct Monte Carlo simulation. Finally, three examples were given to verify the effectiveness of the proposed method. The results show that the sequential simulation method has better computational efficiency and accuracy than that of the direct Monte Carlo simulation method for solving the upper and lower bounds of the rigid-flexible coupling systems large overall motions and vibration responses.

Key words:  , dynamic uncertainty, interval process model, interval K-L expansion, rigid-flexible coupling dynamics, sequential simulation method

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