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研究了结构参数不确定性对机翼颤振临界风速的影响。在确定性机翼颤振分析模型的基础上,考虑结构参数不确定性对机翼颤振的影响,将它们区间化,借助一阶Taylor级数展开,给出了阻尼振动对数衰减率随风速变化的上下界曲线,进而可得到机翼颤振临界风速的区间估计,这比忽略不确定性的机翼颤振临界风速的点估计更为合理,将为进一步进行机翼颤振的非概率区间可靠性分析奠定基础。文中给出了机翼颤振分析的区间有限元模型的流程图。通过一个三自由度机翼与机身模型和一15度后掠翼模型的数值算例,将本文提出的机翼颤振的区间有限元模型与随机有限元模型进行了比较,显示了本文方法的有效性和可行性。本文方法的显著优点是对于不确定性参数仅需要知道它们的幅值的界限,而不需要知道它们的概率分布密度或概率统计特性。
The influence of uncertainty of structural parameters on the critical flutter speed of the wing was studied. Based on the deterministic wing flutter analysis model, considering the influence of the uncertainty of the structural parameters on the flutter of the wing, they are compartmentalized. With the aid of the first-order Taylor series expansion, the logarithmic decrement of damping vibration The upper and lower bounds of the wind speed change can then be used to estimate the critical wind speed of the wing flutter. This is more reasonable than the point estimate of the wing flutter critical wind speed, which ignores the uncertainty. It will be used for further wing flutter Non-probabilistic interval reliability analysis laid the foundation. In this paper, the flow chart of interval finite element model of wing flutter analysis is given. A finite element model of the wing flutter proposed in this paper is compared with the stochastic finite element model by numerical example of a 3-DOF wing and fuselage model and a 15-degree swept-back wing model. It shows that this method Effectiveness and feasibility A significant advantage of the method in this paper is that it is only necessary to know the limits of their amplitudes for the uncertainty parameters without knowing their probability distribution or probability statistics.