基于四阶特征参数摄动法的航空飞机机翼损伤检测研究

发布时间：2019-01-01 14:31

【摘要】：航空飞机机翼在其使用寿命期间,由于疲劳、腐蚀及意外碰撞等会发生结构的损伤。随着机翼结构损伤程度的提高,会导致航空飞机承载能力的下降,进而可能会发生机翼断裂等事故。本文以建立的特征参数的四阶摄动方程在损伤检测中的应用为目标,以某型号航空飞机的机翼为研究对象,利用特征参数的四阶摄动法对航空飞机机翼进行损伤检测,实现四阶摄动算法在损伤检测方面的价值。主要研究内容与成果有:(1)根据特征值摄动方程和正规化摄动方程,推导了一套完整的包括正交和非正交的四阶特征参数摄动项系数。低阶摄动项和高一阶的摄动项存在着一定的关系,通过低阶摄动项可以方便地求出高阶摄动项。(2)依据特征参数的四阶摄动展开式的余项建立了最小化的目标函数。利用最优化算法中的BFGS算法,利用进退法和黄金分割法完成对BFGS算法的最优步长的寻优,通过对目标函数最优化求解,实现了对特征参数的优化。(3)引入终止指标值对整个迭代过程进行控制。通过终止指标值对优化的特征参数的精度进行控制,实现了对机翼的弹性模量仿真值误差的控制。(4)利用悬臂梁代替机翼的有限元模型进行仿真。通过对三阶摄动算法和四阶摄动算法在不同损伤程度下的仿真数据进行分析,四阶摄动算法在航空飞机机翼损伤检测的效果良好。因此四阶摄动算法比三阶摄动算法能更好的应用于航空飞机机翼的损伤检测。
[Abstract]:Structural damage will occur due to fatigue, corrosion and accidental impact on the wing of an aircraft during its service life. With the increase of the damage degree of the wing structure, it will lead to the decrease of the aircraft's carrying capacity, which may lead to the breakage of the wing. Aiming at the application of the four-order perturbation equation of the characteristic parameters in damage detection, this paper takes the wing of a certain type of aircraft as the research object, and uses the four-order perturbation method of the characteristic parameters to detect the damage of the aircraft wing. The value of the fourth order perturbation algorithm in damage detection. The main contents and results are as follows: (1) according to the eigenvalue perturbation equation and the normalized perturbation equation, a complete set of perturbation coefficients of the fourth order characteristic parameters including orthogonal and non-orthogonal is derived. There exists a certain relationship between the low-order perturbation term and the higher-order perturbation term. By using the low-order perturbation term, the higher-order perturbation term can be easily obtained. (2) based on the remainder of the fourth-order perturbation expansion of the characteristic parameter, a minimized objective function is established. Using the BFGS algorithm in the optimization algorithm, the advance and backward method and the golden section method are used to complete the optimization of the optimal step size of the BFGS algorithm, and the optimization of the objective function is carried out. The characteristic parameters are optimized. (3) the termination index is introduced to control the whole iteration process. The precision of the optimized characteristic parameters is controlled by terminating the index value, and the error of the simulation value of the elastic modulus of the wing is controlled. (4) the finite element model of the wing is simulated by using cantilever beam instead of the wing. By analyzing the simulation data of the third order perturbation algorithm and the fourth order perturbation algorithm under different damage degrees, it is found that the fourth order perturbation algorithm has a good effect on aircraft wing damage detection. Therefore, the fourth order perturbation algorithm is better than the third order perturbation algorithm in the damage detection of aeroplane wing.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V267

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