基于失效物理相关性的风电齿轮箱可靠性分析

摘要

针对传统独立失效理论已不能适用于工程实际,与失效相关有关的数学模型对相关性本质的描述往往较为模糊的问题,从失效物理的角度,以1.5MW风电齿轮箱为研究对象,针对齿轮两失效模式间的失效相关,综合考虑应力相关和强度相关,结合全概率公式建立了考虑强度退化的失效相关联合分布.从失效机理和本质上对风电齿轮箱进行可靠性分析,分析结果表明:失效相关的实质为齿轮的强度和应力中公共随机变量间具有一定的关联性,对风电齿轮箱传动系统的可靠性影响较大.%Aimed at the problem that the traditional independent failure theory has been inapplicable to engineering practice and the characterization of the dependency nature with a mathematical model associated with failure-dependence is often comparatively blurring.Therefore,by means of taking a 1.5 MW wind turbine gearbox as research object,starting from the view point of failure physics,aimed at the failure dependence between any two failure modes of each individual gear in wind turbine gearbox,considering comprehensively the stress dependence and strength dependence,and incorporated with the formula of total probability,the failure dependence joint distribution is established when the strength degradation is taken into consideration.The reliability of wind turbine gearbox is analyzed in connection with the failure mechanism and nature.The analysis result shows that the essence of failure dependence is that there is a certain correlation among the common random variables of gear strength and stress,having a greater impact on the reliability of the wind turbine gearbox transmission system.