Edwin Vijay Kumar and S.K. Chaturvedi
This paper aims to prioritize preventive maintenance actions on process equipment by evaluating the risk associated with failure modes using predictive maintenance data instead of…
Abstract
Purpose
This paper aims to prioritize preventive maintenance actions on process equipment by evaluating the risk associated with failure modes using predictive maintenance data instead of maintenance history alone.
Design/methodology/approach
In process plants, maintenance task identification is based on the failure mode and effect analysis (FMEA). To eliminate or mitigate risk caused by failure modes, maintenance tasks need to be prioritized. Risk priority number (RPN) can be used to rank the risk. RPN is estimated invariably using maintenance history. However, maintenance history has deficiencies, like limited data, inconsistency etc. To overcome these deficiencies, the proposed approach uses the predictive maintenance data clubbed with expert domain knowledge. Unlike the traditional single step approach, RPN is estimated in two steps, i.e. Step 1 estimates the “Possibility of failure mode detection” and Step 2 estimates RPN using output of step 1. Fuzzy sets and approximate reasoning are used to handle the uncertainty/imprecision in data and subjectivity/vagueness of expert domain knowledge. Fuzzy inference system is developed using MATLAB® 6.5.
Findings
The proposed approach is applied to a large gearbox in an integrated steel plant. The gearbox is covered under a predictive maintenance program. RPN for each of the failure modes is estimated with the proposed approach and compared with the maintenance task schedule. The illustrative case study results show that the proposed approach helps in detection of failure modes more scientifically and prevents “Over maintenance” to ensure reliability.
Originality/value
This approach gives an opportunity to integrate the predictive maintenance data and subjective/qualitative domain expertise to evaluate the possibility of failure mode detection (POD) quantitatively, which is otherwise purely estimated using subjective judgments. The approach is generic and can be applied to a variety of process equipment to ensure reliability through prioritized maintenance scheduling.
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Edwin Vijay Kumar, S.K. Chaturvedi and A.W. Deshpandé
The purpose of this paper is to ascertain overall system health and maintenance needs with degree of certainty using condition‐monitoring data with hierarchical fuzzy inference…
Abstract
Purpose
The purpose of this paper is to ascertain overall system health and maintenance needs with degree of certainty using condition‐monitoring data with hierarchical fuzzy inference system.
Design/methodology/approach
In process plants, equipment condition is ascertained using condition‐monitoring data for each condition indicator. For large systems with multiple condition indicators, estimating the overall system health becomes cumbersome. The decision of selecting the equipment for an overhaul is mostly determined by generic guidelines, and seldom backed up by condition‐monitoring data. The proposed approach uses a hierarchical system health assessment using fuzzy inference on condition‐monitoring data collected over a period. Each subsystem health is ascertained with degree of certainty using degree of match operation performed on fuzzy sets of condition‐monitoring data and expert opinion. Fuzzy sets and approximate reasoning are used to handle the uncertainty/imprecision in data and subjectivity/vagueness of expert domain knowledge.
Findings
The proposed approach has been applied to a large electric motor (> 500kW), which is treated as four subsystems i.e. power transmission system, electromagnetic system, ventilation system and support system. Fuzzy set of condition‐monitoring data of each condition indicator on each subsystem is used to ascertain the degree of match with the expert opinion fuzzy set, thus inferring the need for periodical overhaul. Subjective expert opinion and quantitative condition‐monitoring data have been evaluated using hierarchical fuzzy inference system with a rule base. It is found that the certainty of each subsystem's health is not the same at the end of 600 days of monitoring and can be classified as “very good”, “good”, “marginal” and “sick”. Degree of certainty has helped in taking a managerial decision to avoid “over‐maintenance” and to ensure reliability. Large volumes of condition‐monitoring data not only helped in assessing motor overhaul health, but also guide the maintenance engineer to suitably review maintenance/monitoring strategy on similar systems to achieve desired reliability goals.
Practical implications
Condition‐monitoring data collected for long periods can be utilized to understand the degree of certainty of degradation pattern in the longer time frame with reference to domain knowledge to improve effectiveness of predictive maintenance towards reliability.
Originality/value
The paper gives an opportunity to evaluate quantitative condition‐monitoring data and subjective/qualitative domain expertise using fuzzy sets. The predictive maintenance cycle “Monitor‐analyse‐plan‐repair‐restore‐operate” is scientifically regulated with a degree of certainty. Approach is generic and can be applied to a variety of process equipment to ensure reliability through effective predictive maintenance.
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Anand Vijay Satpute and E. Vijay Kumar
This paper aims to review the role of government initiatives for the development of wind power industries in India, to provide better and benevolent policies in the production of…
Abstract
Purpose
This paper aims to review the role of government initiatives for the development of wind power industries in India, to provide better and benevolent policies in the production of wind energy density and to maximize the use of the renewable source of energy which permits to reduce carbon emission from the coal-based power plant and to curtail tackle need of society and mitigate poverty.
Design/methodology/approach
The present study is carried out on the current position of wind power generation in India. Government policies for promoting clean energy and associated problems are also analysed herein detail. However, secondary approaches are opted in terms of alertness of caring for the environment hazardous and reduced the major economies aspects by fulfilling the schema of Kyoto Protocol and Paris Agreement, United Nations Framework Convention on Climate Change.
Findings
The prospective of wind energy generation is huge, as an ancient source of energy, wind can be used both as a source of electricity and for agricultural, irrigation uses. The study of wind turbine blades and its features showed how it can be properly fabricated and used to extract the maximum power, even at variable and low wind speeds.
Research limitations/implications
Although India has achieved a remarkable advancement in wind power sectors, it needs to eradicate all the loopholes to evolve as super power in wind energy sector leaving behind its rivalry China. To do this, it is required to develop in many fields such as skilled manpower, advancement in research and development, grid and turbine installation, proper distribution, smooth land acquisition, modern infrastructure, high investment and above all industry friendly government policy.
Practical implications
The present study finds out effects of wind power energy as a source of renewable energy to mitigate energy crisis.
Social implications
As a source of renewable energy and cost effectiveness, wind power can be evolved as a potential means enhance social life.
Originality/value
The present paper caries out critical analysis for the active use of renewable energy in the present and forthcoming days. Such unique analysis must help India as a developing nation to balance its energy crisis.
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Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…
Abstract
Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.
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The main purpose of the present work is to study the effect of tool pin profiles on mechanical properties of welded plates made with two different aluminium alloy plates.
Abstract
Purpose
The main purpose of the present work is to study the effect of tool pin profiles on mechanical properties of welded plates made with two different aluminium alloy plates.
Design/methodology/approach
The welded plates were fabricated with the three different kinds of pin profiled tools such as taper cylindrical, taper threaded cylindrical and stepped cylindrical pin profiles. Tensile properties of welded plates were evaluated using tensile testing machine at room temperature. Microstructures studies were carried out using scanning electron microscope.
Findings
Tensile properties were improved with the use of taper threaded cylindrical pin tool in friction stir welding process when compared with taper cylindrical and stepped cylindrical pin tools. This is due to refinement of grains and mixing of plasticized material occurred with generation of sufficient heat with the taper threaded pin tool. Through these studies, it was confirmed that friction stir welding can be used to weld Al6061 and Al2014 aluminium alloy plates.
Research limitations/implications
In the present study, the friction stir welding is performed with constant process parameters such as tool rotational speed of 900 rpm, transverse speed of 24 mm/min and tilt angle of 1°.
Practical implications
Aluminium alloys are widely using in automotive and aerospace industries due to holding a high strength to weight property. These aluminium alloy blanks can be developed with friction stir welding method with better properties.
Originality/value
Very limited work had been carried out on friction stir welding of aluminium alloys of Al 6061 and Al2014 with different tool pin profiles. Furthermore, this work analyzed with tensile properties of welded plates correlated with weld zone microstructures.