为了预测装载机动臂的可靠度,将动臂结构尺寸、材料属性和外载荷等参数视为随机变量,基于响应面法建立了动臂结构可靠性分析模型。该模型考虑了外载荷变化对动臂结构可靠性的影响,结合一次二阶矩法求解模型可靠度。利用该模型对ZL50型装载机动臂可靠性进行研究。结果表明,动臂的稳定性可靠度与铲装作业时所受外载荷为非线性关系,外载荷均值增大时,动臂可靠度以结构设计极限载荷为分界,呈现出不同的降低趋势。用S曲线模型可以很好地描述动臂可靠度与外载荷的变化规律。研究方法和结果为装载机动臂结构稳定性分析和结构优化提供了参考。 In order to predict the reliability of loader boom, parameters of boom structure size, material properties and external load are regarded as random variables, and the reliability analysis model of boom structure is established based on response surface method. The model considers the influence of the external load variation on the structural reliability of the boom, and combines the first order second moment method to solve the model reliability. The model is used to study the reliability of the ZL50 loader boom. The results show that the reliability of the boom is nonlinear with the external load of the shoveling operation. When the mean value of the external load increases, the boom reliability shows a decreasing trend with the structural design limit load as the boundary. The S-curve model can well describe the variation of boom reliability and external load. The research methods and results provide a reference for structural stability analysis and structural optimization of loader boom.