Mechanism of Fretting Fatigue and Methods by Which This Mode of Mechanical Failure Might be Avoided - Essay Example

Discuss the mechanism of fretting fatigue and the methods by which this mode of mechanical failure might be avoided in terms of design and installation practice The importance of well-designed plan cannot be undermined in any kind of industry. For the smooth running of a business or industry, adequate flow of funds, resources and a better managerial policy are crucial components. Even though the existence of an industry requires appropriate margin of profit, the fact that the business or industry should carry out its operations for a long period of time is also important, and this is possible only through the application of plans and policies in a systematic manner. These days, mechanical industry has a wider scope. However, in case of mechanical industry, the chance of occurrences of fretting fatigue is very high. The mechanism of fretting fatigue is very complex in nature; and it relies heavily on several factors. It is extremely important for the industry to understand the mechanism behind the fretting fatigue. Therefore, an effective analysis is a pre-requisite for this concept, and a marked attitudinal change and positive mindset are also required for successfully tackling such failures. The significant areas where the concentration need to be made should be identified. Controlling the mechanism and development of various test methods are also essential. The term itself indicates that fretting fatigue means fissures from the outer side of a one particular constituent by excluding the rest of the constituents. “Fretting Fatigue has proved a challenging problem from the design perspective and a significant number of fretting related failures still take place in service. Two features make analysis of the crack nucleation and short crack growth phases of life particularly demanding. These are the existence of high stress gradients, which can lead to a size effect, and the difficulty in quantifying the effect of surface damage on crack nucleation. Both of these difficulties can be overcome, at least in terms of analyzing fatigue thresholds, by considering the possibility of short crack arrest. The argument assumes that conditions at the frictional interface are so severe that cracks are highly likely to nucleate. The difference between finite life and ‘infinite life’ is therefore attributed to whether these embryo cracks are able to escape from the highly localized stress concentration caused by the contact.” (Novell 2007). Fretting failure is a highly intricate problem and any attempt to provide an explanation for it needs to analyze the root causes for it and trace its evolutionary process apart from devising on effective system for the management of data involved. Based upon the specific reasons for the failures it is possible to help in the process of methods of isolating and removing the future fatigues at the earliest and thus help in avoiding their occurrences. In this connection, it needs to be emphasized that preventive measures designed for the prevention or arrest of the problem assumes more significance than the elimination of fretting failure after its occurrence since it could cause many problems and could stall the process. Therefore, it is necessary that the management take necessary steps and procedures in order to identify and eliminate the causes of the fretting problems and try to solve them before they could assume grave propositions and cause harm. It is for the very same reason that preventive maintenance should be a priority area in project management and it should be regularly done. It is now proposed to take up certain functional areas in which the matter of fretting failures may be significant as, in the medical areas of artificial hip replacement, electrical conductors, aerospace and power generating industries. (Dini and Hills 2007) Fretting failures are also a major issue in gas turbine engines. The merger of roots is the most predominantly used method for attaching components in their respective slots. However, sometimes it may happen that this may get displaced which could, in turn, lead to fretting failures. Besides the medial and industrial engineering fields this concept became a leading problem in the mechanical industry nowadays. Those factors, which are highly influencing fretting are taken in to consideration and should be investigated for minimizing its occurrence. Therefore, it is necessary to reduce the fretting fatigue crack growth in an appropriate manner. Mainly, three mechanisms are widely applicable in this regard. These are: It is not possible to change the model of a sample through flexible displacements which is very critical in nature. The application of flexible displacement may some times lead to fretting fatigue. To remove or disconnect the sub portion so obtained. (Vincent et al 1992). Most of the small cracks are originated within a system and these will be mostly around 10%of the whole life cycle. The major analysis so conducted very recently about the fretting fatigue as mentioned is that the occurrence of fretting fatigue is related to mechanical damage rather than chemical deterioration. The main limit of fretting fatigue is restricted up to a certain level. It is essential to make a detailed analysis of the fretting fatigue in a systematic manner, and then only it will be possible to rectify such defects. In order to evaluate and understand the fretting fatigue, it is necessary to take into account the basic limitations of this concept. The consequences of restrictive stress should be taken in to account because it is a major constituent that leads to fretting. “Systematic experimental studies to define crack formation and lower-bound fatigue thresholds for the growth of "small" and “large” cracks at high load ratios, high frequencies, and with superimposed low cycle loading, in the presence of primary tensile and mixed-mode loading.  Analysis of the applicability of the threshold stress-intensity factors to characterize crack initiation and growth in engine components subjected to high cycle fatigue.” (Boyce 1999). The minimization of this fretting fatigue is an important concept for enhancing the industrial development and capability. The environmental factors are also taken up effectively while dealing with the fretting fatigue. In addition to this, the effects of time and temperature are also relevant phenomena in this regard. However, the fretting wear takes place in unsafe environment, the consequences of which are higher in nature. “Cyclic motion between the contacting surfaces is the essential ingredient in all types of fretting wear. It is a combination process that requires surfaces to be in contact and be exposed to small amplitude oscillations.” (Fitch 2007). This concept is widely applicable in the mechanical industry, technological improvement, engineering and manufacturing services for the automobile industry. In terms of design and installation practices, a number of design process and procedures are being offered by this sector. Moreover, it is focusing on mechanical tests. By avoiding this fatigue, it is possible to improve the industrial capability. It is essential to take certain effective control measures for bringing down the fretting fatigue. It is necessary to analyze how to minimize the fretting fatigue through its implementation methods in terms of design and installation practice.  Mechanical failure leads to put down in industrial effectiveness, so it has become very important to minimize the fretting fatigue. For this, it is necessary to analyze and evaluate the major reasons for such an industry failure due to this fretting, and to take effective steps to solve this. Otherwise, it will entail the stoppage of production, processing, implementation of designs will adversely affect and the business as a whole. This is a concept, which should give its stress for improving the industrial capability. “Improved materials and materials processing can and must play a large role in generating productive and effective responses to the forces that will drive the automotive industry in the future. However, these forces often pull in diverse directions when specific technological actions are considered. For example, aluminum alloys can be used to reduce vehicle weight, thereby reducing emissions and improving fuel economy, but the added materials costs currently offset these advantages for many applications. As a result, steel is still the major material of choice for automobile construction today and will be difficult to supplant for the foreseeable future.” (Material research agenda for the automobile aircraft industries 1993). The methods by which the Fretting failures can be avoided can be discussed as follows: Mechanical problems lead to the industry failure and it also relates to the organizational aspect of controlling the required source of water resources. The ultimate changes in the area of engineering are required in case of those industries relating to production. Moreover, it is necessary to make a review about all the areas of operations within the industry, because the persons who are responsible for this industrial segment have to sustain various operations, take effective measures for improvement, and also develop innovative measures. The mechanical engineers are in a position to provide their full supports in almost all areas. Currently, there is a growing demand for the services of mechanical and automobile engineers, due to the higher level of transportation link. Further, mechanical engineers are widely relying on various policies and procedures of materials, energy, and several kinds of tools. One of the complicated and difficult areas of work so undertaken by the engineers is installation and designing, because it requires a lot of technical knowledge and working skills.   The testing of the equipment before the use of the fasteners could be a safeguard and the use of higher diameter equilibrium fasteners as compared to lower diameter should be made. In addition, through the use of lubricants on the surface coating the chances of the onset of fretting, which could delay the fatigue and thus promote the longevity of the system, could be minimized. However, the use of lubricants could depend on many external factors like the quality and ingredients of the lubricants, its viscosity, and the mode of its application on the metal surface. It has been found out that the more effective and efficient method would be to ‘avoid the relative motion in the contact region of mated connector parts by a special contact design.” (Horn et al 2004). Basically speaking, the rapid corrosion occurs at the interaction between the contracting and heavily loaded metal surfaces when it is undergoing vibratory movements. This constant friction reduces the coating of the surfaces, which could be further aggravated by oxidization process. The result of oxidation is that there is a marked difference between the internal surfaces of the connector and the exterior, because of which the chances of incurring fretful failures is accentuated. It is very essential to overcome the problems of mechanical failure in relation to design and installation practices. Most of the mechanical industries are suffering from a key problem of lack of managerial planning. In order to resolve these problems and to develop the overall functions of the industry, it is necessary to make a proper plan about the down time, and also avoid the spontaneous work schedule. Great care should also be given during the design and installation practices. Otherwise the whole plan will become a waste. In addition to this, mechanical industry is facing a lot of power related problems like over and under voltage, lack of adequate energy etc. Therefore, it is necessary that the management should pay adequate attention to the planning and organizational aspects of the machineries in order to avoid the need for heavy investments in repairs and maintenance in future years. Thus it becomes evident that at the installation stage itself it is necessary to take adequate care of the machines and observe necessary precautions to avoid unnecessary and wasteful expenditures, which would affect the bottom line and reduce profits substantially. Conclusion: It is seen from the above discussions that although the causes for fretting failures may be determined, the process for its arrest and elimination needs to be done thorough study and practical implementation. Therefore, the management of any progressive minded organization should strive to identify the source the problem, seek the help of experienced professionals, and thus obviate the need for expenditures on this count in future. Works Cited BOYCE, brad L (1999). Excerpted from 1999 Annual Report on the MURI on HCF. Objectives. [online]. Air force programme summary. Last accessed 30 August 2007 at: http://www.lbl.gov/Ritchie/Programs/URI/overview.html DINI, D and HILLS, D.A (2007). Progress in understanding fretting contact problems. One day meeting on fretting. [online]. University of leeds. Last accessed 30 August 2007 at: http://www.mech-eng.leeds.ac.uk/fretting-meeting/abstracts.pdf FITCH, E.C (2007). Practicing Oil Analysis. Fretting wear in lubricated systems. Tribolics Inc. Fretting wear process. Last accessed 30 August 2007 at: http://www.practicingoilanalysis.com/article_detail.asp?articleid=693&relatedbookgroup=OilAnalysis HORN, Jocher et al. (2004). Avoiding Fretting corrosion by design. Tyco electronic corporation. [online]. AMP journal of technology. Last accessed 30 August 2007 at: http://www.tycoelectronics.com/documentation/whitepapers/pdf/4jot_1.pdf. Material research agenda for the automobile aircraft industries. (1993). Need for material system approach. [online]. The national academies press. Last accessed 30 August 2007 at: http://books.nap.edu/openbook.php?record_id=2244&page=29 NOVELL, D (2007). Discuss mechanism fretting fatigue. Short crack arrest approaches for prediction of fretting fatigue threshold. [online]. Oxford University. Last accessed 30 August 2007 at: http://72.14.235.104/search?q=cache:mTsdK1c-FYIJ:www.mech-eng.leeds.ac.uk/frettingmeeting/abstracts.pdf+Discuss+the+mechanism+of+fretting+fatigue&hl=en&ct=clnk&cd=7&gl=in VINCENT, L, BERTHIER, Y and GODET, M (1992). Testing Methods in Fretting Fatigue: A Critical Appraisal. [online]. ASTM Digital Library. 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