飞机连接结构防护涂层老化损伤量化评估方法

飞机连接结构防护涂层体系的老化过程具有多属性、模糊性和动态性的特点,综合量化评估防护涂层体系老化损伤程度对保障飞机连接结构的功能和使用安全具有重要作用。本文分析了现阶段的涂层老化损伤评级方法,提出了用等级描述老化损伤程度的量化评估技术途径,建立了基于模糊综合评判的量化评估方法。在国标、ISO和ASTM标准给出的单项评级方法的基础上提出了适用于飞机连接结构防护涂层体系老化损伤的单项评级方法,确定了因素集和评价集。采用专家打分法统计得到了各因素的权重分配,确定了权重集。选用正态分布隶属函数来确定评价矩阵,给出了隶属函数参数的计算方法和结果,建立了评价矩阵的确定方法。进行了某型飞机机翼上下表面连接部位模拟试件的加速腐蚀试验,采用本文提出的量化评估方法对防护涂层体系的老化损伤进行了评估,确定了老化损伤等级,评估结果与试验结果相符,与腐蚀动力学规律一致,从而验证了本文提出的方法。

Quantitative method for evaluating aging damage ofprotective coatings of aircraft joint structures

As the failure of protective coating system of aircraft structures is multiple attributed,fuzzy and dynamical,evaluating the aging damage of the system quantitatively and comprehensively plays an important role in ensuring the function and safety of aircraft structures.This paper analyzes the current methods for rating the aging damage of protective coatings,and proposes a technical approach to describe the level of aging damage.A quantitative evaluation method based on fuzzy comprehensive evaluation is developed.On the basis of the standards of GB,ISO and ASTM,the rating method for individual aging damage index of the protective coating system in aircraft joint structures is provided.The factor set and evaluation sets are determined.The weight set is determined by calculating the weight distribution of each factor with expert scoring method.To establish the evaluation matrix,the normal distribution membership function is used,and the calculation method and results of membership function parameters are then given.To verify the method,the accelerated corrosion tests of specimens which simulate the joint structures of the upper and lower surfaces of the wing are carried out,and the aging damage is then evaluated by the quantitative evaluation method above.The evaluation results are consistent with the test results and the corrosion dynamic pattern,proving the rationality of the method proposed.