scholarly journals Gradual Reliability Sensitivity Analysis of Mechanical Part Considering Preventive Maintenance

2014 ◽  
Vol 6 ◽  
pp. 829850
Author(s):  
Li Changyou ◽  
Liu Haiyang ◽  
Guo Song ◽  
Zhang Yimin ◽  
Li Zhenyuan
Keyword(s):  
Mechanical System ◽  
Preventive Maintenance ◽  
Gamma Process ◽  
Reliability Model ◽  
Application Process ◽  
Initial State ◽  
Reliability Design ◽  
Mechanical Part ◽  
Safety And Reliability ◽  
Deterioration Process

A lot of mechanical parts are subject to failure due to the deterioration. Usually the preventive maintenance is taken to ensure the safety and reliability. Therefore, it is very important to study the gradual reliability design of the mechanical part for improving the gradual reliability of the mechanical system under the condition of considering the preventive maintenance. Beta distribution is employed to describe the randomness of the mechanical part state after the preventive maintenance. The deterioration process of the mechanical part is modeled using the nonstationary Gamma process. The gradual reliability model before the first preventive maintenance is proposed according to the gradual failure principle and using the initial state distribution and the properties of Gamma process. Then, the gradual reliability model between any two times of preventive maintenance is also derived. Subsequently, the sensitivity equations of the proposed gradual reliability model to each parameter are given. The application process and practicality of the proposed approach are described by a numerical example. This work solved the problem where the maintenance has not been well considered in the reliability design of the mechanical part and contributed to the theory and method of improving the safety and reliability operation of the mechanical system.

A degradation model for maintenance improvement in respect of cost and availability

2015 ◽  
Vol 21 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Christophe Letot ◽  
Pierre Dehombreux ◽  
Edouard Rivière-Lorphèvre ◽  
Guillaume Fleurquin ◽  
Arnaud Lesage
Keyword(s):  
Preventive Maintenance ◽  
Residual Life ◽  
Operating Time ◽  
Hitting Times ◽  
Mean Residual Life ◽  
Reliability Model ◽  
Content Type ◽  
Degradation Data ◽  
Specific Item ◽  
The Mean

Purpose – The purpose of this paper is to highlight the need for degradation data in order to improve the reliability and the mean residual life estimation of a specific item of equipment and to adapt the preventive maintenance tasks accordingly. Design/methodology/approach – An initial reliability model which uses a degradation-based reliability model that is built from the collection of hitting times of a failure threshold. The proposed maintenance model is based on the cost/availability criterion. The estimation of both reliability and optimum time for preventive maintenance are updated with all new degradation data that are collected during operating time. Findings – An improvement for the occurrences of maintenance tasks which minimizes the mean cost per unit of time and increases the availability. Practical implications – Inspection tasks to measure the degradation level should be realized at least one time for each item of equipment at a specific time determined by the proposed methodology. Originality/value – The introduction of a criterion which helps the maintainer to decide to postpone or not the preventive replacement time depending on the measured degradation level of a specific item of equipment.

The Doctrine of Manifest Danger and its Relationship to Reliability, Preventive Maintenance and Fail-Safe Design

1993 ◽  
Author(s):  
Ralph L. Barnett
Keyword(s):  
Preventive Maintenance ◽  
Design Concept ◽  
Legal Issue ◽  
Proximate Cause ◽  
Reliability Design ◽  
The Bible ◽  
Safety Technology ◽  
Fail Safe ◽  
Over Time

Abstract “Dust thou art, and unto dust shalt thou return.”1 Man has made no observations that would challenge this notion from the Bible and certainly safeguarding systems fall into lockstep. Safety technology has responded to the reality of eventual degradation using four general approaches: reliability design, preventive maintenance, fail-safe design and danger manifestation. The optimum implementation of these approaches will still not eliminate accidents; indeed, no work of manor nature is or can be danger free. Nevertheless, these sophisticated approaches are capable of producing ever-increasing levels of safety, albeit, with attendant ever-increasing cost. It is at once unfortunate and unacceptable that common law2 is not equally sophisticated in dealing with the inevitable failure of safeguarding systems over time. This paper introduces The Doctrine of Manifest Danger which is defined as a design concept using direct cues or indicator devices to communicate to the community of users that the safety of a system has been compromised before injuries occur. Furthermore, the paper addresses a related legal issue by distinguishing between proximate cause and cause of action.

The RCM Technique Application in NPP Operation and Design Stage

2013 ◽  
Author(s):  
Yang Lifei ◽  
Jiang Hong
Keyword(s):  
Preventive Maintenance ◽  
Early Phase ◽  
Nuclear Safety ◽  
Design Stage ◽  
Safety Regulation ◽  
Positive Role ◽  
Whole Process ◽  
Operation Stage ◽  
Safety And Reliability ◽  
Under Construction

The national nuclear safety regulation commands that the safety, reliability and economy of the NPP must be considered in design and operation stage. In order to reach the goal, the paper firstly introduces how to use the RCM technique to make preventive maintenance programs to ensure the safety and reliability of the NPP which is in service or under construction, and then elaborates how to take the RCM technique into design in the early phase, to promote the safety and reliability of the NPP. It has been considered that RCM technique shows a positive role in the whole process, not only improving the maintenance manage level, but also the safety and reliability at the design stage.

scholarly journals Reliability Modeling and Assessment of Component with Multiple Weak Sites under Complex Loading

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Wenxue Qian ◽  
Xiaowei Yin ◽  
Liyang Xie
Keyword(s):  
Static Loading ◽  
Safety Margin ◽  
Complex Loading ◽  
The Other ◽  
Reliability Model ◽  
Reliability Modeling ◽  
Component Reliability ◽  
Reliability Design ◽  
Practical Engineering ◽  
Weak Site

A component with multiple weak sites is widely used in practical engineering and the existence of multiple weak sites can significantly decrease the component reliability. On the other hand, only a few components bear static loading and most components bear dynamic loading. In this paper, a reliability model of isomorphic component with multiple weak sites is built based on an order statistics model and the influences of strength decentrality and loading decentrality on isomorphic component with multiple weak sites are discussed. Furthermore the influence of loading times is studied in detail. The results show that unlike a component with only one weak site, not only does the failure of a component with multiple weak sites have a relationship with the safety margin, but there also exist relationships with the number of weak sites, the loading roughness, and loading times. The work in this paper is of some guiding significance in reliability design and assessment of a component with multiple weak sites under complex loading.

Theory of Active Reliability-Based Design for Predetermined Life of Structures

2008 ◽  
Vol 44-46 ◽  
pp. 745-750 ◽  
Author(s):  
Chu Liang Yan ◽  
K.G. Liu
Keyword(s):  
Economic Efficiency ◽  
Structural Reliability ◽  
Reliability Assessment ◽  
Economic Life ◽  
View Point ◽  
Reliability Design ◽  
Reliability Based Design ◽  
Fatigue And Fracture ◽  
Safety And Reliability

The project presents the theory of active reliability-based design for predetermined life targeted at their economic life. The structural reliability is designed from the view point of economic efficiency and maintainability requirements, so that the destruction of products led by fatigue and fracture is eliminated to the highest possible degree to provide the longest life, the highest reliability and the lowest cost. The reliability assessment of conventionally finished product is developed into an active reliability design at preset life, which is implemented before the design of products is finalized, to improve the safety and reliability of structures.

Reliability Simulation and Prediction of Mechanical Equipment for Maintenance

2010 ◽  
Vol 139-141 ◽  
pp. 1060-1063
Author(s):  
Liang Pei Huang ◽  
Zheng Li Gong ◽  
Wen Hui Yue
Keyword(s):  
Service Life ◽  
Mechanical System ◽  
Density Function ◽  
System Reliability ◽  
Mechanical Systems ◽  
Mechanical Equipment ◽  
Time To Failure ◽  
Reliability Model ◽  
Estimate Reliability ◽  
Maintenance Policies

The mechanical equipment faults result from parts failure in the period of service time, due to reassembly and maintenance, the reliability model for mechanical equipment is broken, so it is necessary to research and estimate the safety reliability of mechanical system. Based on the time-to-failure density function of parts, the mechanical system reliability model is constructed to track the change course of age structure of part population for the mechanical systems that are reassembled and maintained. By means of simulation of the system reliability model, concerned parameters with mechanical systems service life are defined, it is discussed how the time-to-failure density function have influence on the service life for mechanical systems undergoing reassembly and maintenance. It is significant to estimate reliability and failure rate of systems and to establish reasonable maintenance policies.

scholarly journals Calculation of Vineyard Hail Protection Device

2021 ◽  
pp. 11-20
Author(s):  
David Tavkhelidze ◽  
◽  
Zurab Mchedlishvili ◽  
Omar Tedoradze ◽  
◽  
...  
Keyword(s):  
Mechanical System ◽  
Cell Phone ◽  
Climatic Changes ◽  
Mechanical Parameters ◽  
Protection Device ◽  
Force Analysis ◽  
Mechanical Part ◽  
Hail Net ◽  
A Cell

The kinematic and force analysis of an invented new mechanical system used to protect vineyards and other fruit-bearing plants from hail, which often occurs due to climatic changes, is determined. The system contains levers that support anti hail net. The offered mechanical scheme of system is simple and can be used for all type of vineyards. Moreover, the mechanical part of the system can be controlled remotely by a cell phone. In order to determine the mechanical parameters of the system the calculations are given based on the use of the principle of possible displacements, based on what theoretically is determined the necessary volume of weight of load that leads in motion of the system.

Cost Effective Automatic Garage Door Mechanism With Variable Speed

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuvraj Prajapati ◽  
Shrey Patel ◽  
Monark Shah ◽  
Raj Chokshi ◽  
Om Prakash Shukla
Keyword(s):  
Mechanical System ◽  
Cost Effective ◽  
Industrial Applications ◽  
Variable Frequency ◽  
Variable Speed ◽  
Electrical System ◽  
Variable Frequency Drive ◽  
Mechanical Part ◽  
Day By Day ◽  
At Home

The aim of our project is to provide safety as well as security to people from the largest electromechanical objects which are available at home. An automatic garage door mechanism was selected as a subject of our research as it is the complex electro-chemical object at home. As technology increases day by day every households installs this automatic garage door mechanism. The major problem with the conventional garage door system was child entrapment and people are in wheelchair are also affected by the conventional garage door mechanism. We are planning to eliminate the problems which are available in the conventional garage door mechanism by providing some extra safety and security features to our automatic garage door mechanism.an automatic garage door mechanism is the combination of mechanical and electrical system in which mechanical system guides the system as well as direct the shutter movement While, electrical system is used to provide energy to mechanical part. Sectional overhead doors have become the standard door type for garages. Our motive behind this study is to increase the safety and security of the automatic garage doors as well as make it to operatable at variable speed. Safety of the equipment is going to be increased by an area presence sensor which will reduce the child entrapment cases. Only authorized people can access the garage, that will increase the security and use of the VFD-variable frequency drive will make the garage door operatable at owner desired working speed. These shutters can be used for home applications as well as industrial applications.

Research on Reliability Design Theory and Methods of CNC System

2009 ◽  
Author(s):  
Taiyong Wang ◽  
Qingjian Liu ◽  
Yunfeng Wang ◽  
Jianhai Yue ◽  
Dafeng Jin
Keyword(s):  
Design Theory ◽  
Evaluation Method ◽  
Fuzzy Mathematics ◽  
Reliability Model ◽  
Cnc System ◽  
Reliability Design ◽  
Structure Reliability ◽  
Embedded Computer ◽  
Computer Numerically Controlled ◽  
Function Module

This paper presents the methods on the structure reliability design of embedded computer numerically controlled (CNC) system. An effective reliability model is developed and tested in a real-time CNC system. The evaluation method for the importance of the reliability of each function module of CNC systems is also investigated. Fuzzy mathematics is used to judge the importance of module reliability design. Cases studies have been performed to validate and illustrate all the analysis.

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