scholarly journals Maintenance Strategy Based on Reliability Analysis and FMEA: A Case Study for Hydraulic Cylinders of Traditional Excavators with ERRS

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qingliang Zeng ◽  
Wenting Liu ◽  
Lirong Wan ◽  
Chenglong Wang ◽  
Kuidong Gao

A simple and effective mechanical parts maintenance approach with lower cost is urgently needed by the cost-sensitive manufactures for traditional excavators (HE). This paper proposes maintenance strategy for hydraulic cylinders (HC) of HE with energy regeneration and recovery system (ERRS). Reliability analysis and FMEA of historical failure data are applied to make maintenance strategy. In this study, the failure data required for reliability analysis are collected from the manufacturers and users over two and a half years, Excel is used as statistical tool, Minitab is used for parameter estimation, and Kolmogorov–Smirnov test is used to reject or accept the hypothesis of the distribution model. The reliability parameters R(t), Rset, and R∗(t) are determined and parameter β∗ is the reference value for making countermeasures and maintenance policies properly for the failure modes of the new HC of HE with ERRS. The purpose of this paper is to make proper maintenance policies and to maintain a high availability level and fulfill the user’s needs for HC, which also paves the way for further reliability study about ERRS.

2013 ◽  
Vol 770 ◽  
pp. 289-293
Author(s):  
Guang Jun Liu ◽  
Bang Xin Han ◽  
Guang Yu Tan ◽  
Guang Hui Li ◽  
Yuan Tao Sun

t is hard to acquire the failure data of ship unloader and the mean time to failure is not independent identically distributed, and there are many defects existed in the maintenance method such as high cost and bad effect. In this work, we propose a method based on Weibull Distribution model to deal with the failure data of a large-scale grab ship unloader, build up the model of MTBF (Mean Time Between Failure) and preventive maintenance time, and show the example with failure data, which provides references to maintenance of the ship unloader. Finally, we present the decision process of the reliability-centered maintenance strategy, maintenance type of the grab ship unloader and the maintenance of the key parts, which provides scientific decision support for the maintenance of the ship unloader equipments.


Author(s):  
Qingan Qiu ◽  
Baoliang Liu ◽  
Cong Lin ◽  
Jingjing Wang

This paper studies the availability and optimal maintenance policies for systems subject to competing failure modes under continuous and periodic inspections. The repair time distribution and maintenance cost are both dependent on the failure modes. We investigate the instantaneous availability and the steady state availability of the system maintained through several imperfect repairs before a replacement is allowed. Analytical expressions for system availability under continuous and periodic inspections are derived respectively. The availability models are then utilized to obtain the optimal inspection and imperfect maintenance policy that minimizes the average long-run cost rate. A numerical example for Remote Power Feeding System is presented to demonstrate the application of the developed approach.


2021 ◽  
Vol 163 ◽  
pp. 104385
Author(s):  
We Wang ◽  
Gang Shen ◽  
Yimin Zhang ◽  
Zhencai Zhu ◽  
Changyou Li ◽  
...  

2011 ◽  
Vol 462-463 ◽  
pp. 1164-1169
Author(s):  
Jing Xiang Yang ◽  
Ya Xin Zhang ◽  
Mamtimin Gheni ◽  
Ping Ping Chang ◽  
Kai Yin Chen ◽  
...  

In this paper, strength evaluations and reliability analysis are conducted for different types of PSSS(Periodically Symmetric Struts Supports) based on the FEA(Finite Element Analysis). The numerical models are established at first, and the PMA(Prestressed Modal Analysis) is conducted. The nodal stress value of all of the gauss points in elements are extracted out and the stress distributions are evaluated for each type of PSSS. Then using nonlinear least squares method, curve fitting is carried out, and the stress probability distribution function is obtained. The results show that although using different number of struts, the stress distribution function obeys the exponential distribution. By using nonlinear least squares method again for the distribution parameters a and b of different exponential functions, the relationship between number of struts and distribution function is obtained, and the mathematical models of the stress probability distribution functions for different supports are established. Finally, the new stress distribution model is introduced by considering the DSSI(Damaged Stress-Strength Interference), and the reliability evaluation for different types of periodically symmetric struts supports is carried out.


2014 ◽  
Vol 903 ◽  
pp. 408-413 ◽  
Author(s):  
FRESELAM Mulubrhan ◽  
Ainul Akmar Mokhtar ◽  
Masdi Muhammad

This paper presents a mathematical model to estimate the life cycle cost (LCC) of heat exchanger and pump. Maintenance cost, down time cost and acquisition costs are calculated. The main uncertainty in calculating these costs are prediction of number of failure and cumulative down time. Number of failure is determined using failure and repair time density function. According to the characteristic that the cumulative failure probability observed, a Weibull distribution model is used. The scale and shape parameters of the Weibull are extracted from the published data. The results of the study show that 71.3% loss in the reliability of heat exchanger and 34.2% reliability loss in pump could lead to 66.2 % increment of the total cost. The reliability of the system decreases because of number of failures will increase each year, and this failure leads to unavailability of the system.Therefore in order to achieve higher system effectiveness and reduce the total LCC, the reliability of the systems need to be increased through proper maintenance policies and strategies. The results of the study could assist the managers to make decision with high degree of accuracy.


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