Abstract
To evaluate the fatigue reliability of the excavator working device, the fatigue tests of 2 sets of moving arm and bucket rod of medium-sized excavators with self-weight of 26000 kg were carried out. The virtual augmented sample method (VASM) combined with Bootstrap method was used to analyze the reliability of the excavator working device under extreme small samples, and the interval and point estimations of life parameters were obtained. Based on the lognormal distribution of the excavator working device, the reliability evaluation model of the excavator working device was esTablelished, and reliability indexes, such as reliability function, failure distribution function, inefficiency function, reliable life and so on, were obtained. And the results of fatigue safety life under different confidence and reliability were calculated. The evaluation results show that the average failure time of the excavator working device is 5885 hours under the confidence of 75%, which provides an important reference for the design, the safety inspection and maintenance decision of the excavator working device.
Highlights
The working device of the excavator is the direct actuator of the excavator operation, and the reliability of the working device is one of the key indexes of the excavator's quality
The fatigue reliability evaluation of excavator working device is a problem of very small sample
The Bootstrap method has been applied to the interval estimation of parameters with a small sample on mechanical engineering field, i.e., the tank roadarm [12], the gearbox [13] and the production processing [14]
Summary
The working device of the excavator is the direct actuator of the excavator operation, and the reliability of the working device is one of the key indexes of the excavator's quality. The fatigue reliability evaluation of excavator working device is a problem of very small sample. Under the condition of no empirical data, the student-t distribution method can be used in the case of the small sample with the unknown parent variance to deduce the interval estimation of the overall mean of the set confidence level. The Bootstrap method has been applied to the interval estimation of parameters with a small sample on mechanical engineering field, i.e., the tank roadarm [12], the gearbox [13] and the production processing [14]. According to the results of the small sample fatigue test, the Bootstrap method combined with VASM was used to evaluate the actual fatigue reliability of the medium-sized excavator working devices
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
