基于直接概率积分法的舰载机起落架随机响应与可靠性分析

Random responses and reliability analysis of carrier-based aircraft landing gear based on direct probability integral method

  • 摘要: 考虑到设计、制造中起落架参数的随机不确定性,本文开展了舰载机着舰冲击随机响应和起落架缓冲性能的不确定性量化研究。首先,建立某型舰载机主起落架落震动力学模型,然后基于起落架缓冲器部分填充参数(如空气腔初始体积以及压油面积、油液缩流系数等)的统计特征,采用直接概率积分法(DPIM)划分代表性点集,并求解代表性点集上的确定性结构方程与概率密度积分方程,同时采用蒙特卡洛方法证明了DPIM在起落架随机模型上应用的准确性。以起落架的缓冲器行程、垂向轮胎力以及支柱轴向力为输出响应,得到响应的均值、标准差、概率密度函数及相关特征,发现虽然响应的分布集中在均值附近,但还是存在较大响应导致系统失效的可能性,进而利用缓冲器行程、垂向轮胎力以及支柱轴向力定义了功能函数,给出了不同阈值下起落架结构的可靠性评估。

     

    Abstract: Considering the random uncertainty of landing gear parameters in design and manufacturing, this study conducts a quantitative study on the random response of Carrier-based aircraft landing impact and the buffering performance of landing gear. Firstly, this study established a dynamic model of the landing vibration of a Carrier-based aircraft’s main landing gear. Then, based on the statistical characteristics of some filling parameters of the landing gear buffer (such as the initial volume of the air chamber, pressure oil area, oil shrinkage coefficient, etc.), the representative point set is divided by the direct probability integration method (DPIM), and the deterministic structural equation and probability density integration equation on the representative point set are solved. At the same time, the accuracy of DPIM application in the landing gear stochastic model is demonstrated by using the Monte Carlo Simulation (MCS) method. By outputting the buffer stroke of the landing gear, the vertical tire force, and the axial force of the strut, the mean value, standard deviation, probability density function, and related features of these responses are obtained. It is found that although the distribution of these responses are concentrated near the mean value, there is still a possibility of significant responses leading to system failure. Therefore, a functional function is defined using the buffer stroke, vertical tire force, and the axial force of the strut, and a reliability evaluation study is conducted on the landing gear structure under different threshold values.

     

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