基于实测谱的挖机工作装置台架疲劳试验姿态及加载方式研究

RESEARCH ON PLATFORM FATIGUE TEST ATTITUDE AND LOADING MODE OF EXCAVATOR WORKING DEVICE BASED ON MEASURED SPECTRUM

以某型挖掘机工作装置为研究对象,采用数值仿真分析方法对7种不同受载状态的应力响应进行求解,选取了动臂及斗杆的7个较大应力点作为有效测点。在试验数据(油缸位移,应力等)分析的基础上,确定了以工作装置发挥的最大挖掘力的姿态为疲劳试验应力响应的"敏感"姿态和等效加载在中间斗齿某一响应"敏感"方向,仿真及试验数据分析结果表明:当动臂、斗杆及铲斗油缸长度分别为:2 463 mm,2 935 mm,2 229 mm时的工作装置姿态发挥最大挖掘力的试验姿态;中间斗齿等效加载力与水平正向成-13°的加载方向为应力响应因子K值的最大方向。由此解决了在台架试验中,由于多自由度系统工作姿态多样性所造成在随意固定姿态和加载方向下疲劳失效位置与实际位置不一致问题。该方法能够有效解决实验室环境下工作装置的姿态及加载方向的问题,并为类似多自由度系统的台疲劳试验姿态确定问题提供参考。

Taking the working device of a certain type of excavator as the research object,,through the method of market research and the simulation analysis of the validated FEM by static calibration experiment to determine the dangerous position of working device,basing on the experimental data(cylinder displacement,stress etc.),first take the maximum digging force posture for fatigue test of stress response as "sensitive" posture and loading in the middle of the bucket tip and the level of positive response at-13 DEG direction " sensitive" as direction,solving the multi degree of freedom system actual attitude multiplicity the real danger caused deviation of the object of any other fixed posture and loading direction of the problem.Secondly,the load of the dangerous point spectrum as the driving load spectrum of tip loading force equivalent,finally through the damage consistency test results show that the experimental method is reasonable,which can effectively solve the problem of posture and loading under the laboratory environment working device,to provide reference for similar and Taiwan fatigue experiment of multi degree of freedom system.