Kerry S. Checkwitch, A. Glover, Thomas Van Hardeveld
A recent business process re-engineering effort undertaken at NOVA Gas Transmission Ltd. provided an opportunity to completely review and improve upon strategies and methodologies used in the maintenance of a very complex natural gas transportation system. In order to achieve safety and reliability in an expanding and aging system, a completely new approach to maintenance planning was adopted based on a Reliability-Centered Maintenance strategy. This is the first application of this approach to a gas transportation system. Development of this maintenance methodology, its major components, and specifically how it has been applied to a pipeline are discussed. The integration of this strategy into a complete pipeline integrity management system allowing full assessment of all hazards specific to the pipe is also reviewed. Examples of results and benefits from the first systems analyzed using this new approach are presented.
NOVA Gas Transmission Ltd.最近进行的业务流程重组工作为全面审查和改进非常复杂的天然气运输系统维护中使用的策略和方法提供了机会。为了在一个不断扩展和老化的系统中实现安全可靠，采用了一种基于以可靠性为中心的维修策略的全新维修计划方法。这是该方法在天然气输送系统中的首次应用。讨论了这种维护方法的发展，其主要组成部分，特别是如何将其应用于管道。将该策略整合到完整的管道完整性管理系统中，允许对管道特定的所有危害进行全面评估。给出了使用这种新方法分析的第一个系统的结果和效益的例子。
{"title":"Reliability-Centered Maintenance Approach Applied to a Pipeline","authors":"Kerry S. Checkwitch, A. Glover, Thomas Van Hardeveld","doi":"10.1115/imece1996-0867","DOIUrl":"https://doi.org/10.1115/imece1996-0867","url":null,"abstract":"\u0000 A recent business process re-engineering effort undertaken at NOVA Gas Transmission Ltd. provided an opportunity to completely review and improve upon strategies and methodologies used in the maintenance of a very complex natural gas transportation system. In order to achieve safety and reliability in an expanding and aging system, a completely new approach to maintenance planning was adopted based on a Reliability-Centered Maintenance strategy. This is the first application of this approach to a gas transportation system. Development of this maintenance methodology, its major components, and specifically how it has been applied to a pipeline are discussed. The integration of this strategy into a complete pipeline integrity management system allowing full assessment of all hazards specific to the pipe is also reviewed. Examples of results and benefits from the first systems analyzed using this new approach are presented.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79152103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There are numerous situations in industry where rotating disks are subjected to cyclic thermal loading. If the operating thermal loading remain in the shakedown region, no plastic deformation occur and the system works safely. However, depending on the speed of cooling and other operating situations, inelastic deformation and incremental growth of the structure in question may occur. This may lead to the incremental deformation, and eventually incremental collapse of the mechanical components. Accordingly. it is essential to develop a numerical method to predict the ine|astic response of mechanical components to the thermal or thermo-mechanical loading. Analysing the aformentioned problems is quit complex, accordingly in this reaserch effort we begin with a simple case. In this paper a numerical method is presented for estimating the thermoelatoplastic stresses developed in a rotating disk, subjected to temperature gradient. The disk’s temperature in the radial direction varies from 100 °F temperature to 1500 °F. The steady state temperature distribution is evaluated using the familiar Carslaw and Jeagar equations. For inelastic behavior of the disk a combined analytical and numerical method is presented. The properties of the material are assumed to be temperature dependent. The material is also assumed to be characterized by nonlinear strain hardening. For this analysis a quasi static uncoupled thermoelastoplastic solution is presented. The problem is also solved for a case when the properties of material are not function of temperature. The effect of temperature dependency of the material on the results is investigated.
{"title":"Thermoelastoplastic Stresses in a Rotating Disk of Temperature Dependent Properties With Temperature Gradient","authors":"S. Jahanian","doi":"10.1115/imece1996-0861","DOIUrl":"https://doi.org/10.1115/imece1996-0861","url":null,"abstract":"\u0000 There are numerous situations in industry where rotating disks are subjected to cyclic thermal loading. If the operating thermal loading remain in the shakedown region, no plastic deformation occur and the system works safely. However, depending on the speed of cooling and other operating situations, inelastic deformation and incremental growth of the structure in question may occur. This may lead to the incremental deformation, and eventually incremental collapse of the mechanical components. Accordingly. it is essential to develop a numerical method to predict the ine|astic response of mechanical components to the thermal or thermo-mechanical loading. Analysing the aformentioned problems is quit complex, accordingly in this reaserch effort we begin with a simple case.\u0000 In this paper a numerical method is presented for estimating the thermoelatoplastic stresses developed in a rotating disk, subjected to temperature gradient. The disk’s temperature in the radial direction varies from 100 °F temperature to 1500 °F. The steady state temperature distribution is evaluated using the familiar Carslaw and Jeagar equations. For inelastic behavior of the disk a combined analytical and numerical method is presented. The properties of the material are assumed to be temperature dependent. The material is also assumed to be characterized by nonlinear strain hardening. For this analysis a quasi static uncoupled thermoelastoplastic solution is presented. The problem is also solved for a case when the properties of material are not function of temperature. The effect of temperature dependency of the material on the results is investigated.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88177706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The stress distributions of single-lap adhesive joints of dissimilar adherends subjected to external bending moments are analyzed as a three-body contact problem by using a two-dimensional theory of elasticity (plain strain). In the analysis, dissimilar adherends and an adhesive are replaced by finite strips, respectively. In the numerical calculations, the effects of Young’s modulus ratio, adherend thickness ratio and adherend length ratio on the stress distribution at the interface are examined. As the results, it is seen that the stress singularity occurs at the edges of the interfaces and it increases at the edge of the interface of adherend with greater Young’s modulus It is noticed that the singular stress decreases at the edge of the interface of adherend with larger adherend thickness. Strain measurements on adherends were conducted. A fairly good agreement is seen between the analytical and the measured results.
{"title":"Two-Dimensional Stress Analysis of Single-Lap Joints of Dissimilar Adherends Subjected to External Bending Moments","authors":"K. Nakano, T. Sawa, H. Toratani","doi":"10.1299/KIKAIA.62.2580","DOIUrl":"https://doi.org/10.1299/KIKAIA.62.2580","url":null,"abstract":"\u0000 The stress distributions of single-lap adhesive joints of dissimilar adherends subjected to external bending moments are analyzed as a three-body contact problem by using a two-dimensional theory of elasticity (plain strain). In the analysis, dissimilar adherends and an adhesive are replaced by finite strips, respectively. In the numerical calculations, the effects of Young’s modulus ratio, adherend thickness ratio and adherend length ratio on the stress distribution at the interface are examined. As the results, it is seen that the stress singularity occurs at the edges of the interfaces and it increases at the edge of the interface of adherend with greater Young’s modulus It is noticed that the singular stress decreases at the edge of the interface of adherend with larger adherend thickness. Strain measurements on adherends were conducted. A fairly good agreement is seen between the analytical and the measured results.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74994847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The thermal stress distributions of laminated composite finite hollow cylinders restricted at both ends and at one end of the cylinders are analyzed using the thermoelastic displacement potential and Michell’s stress functions based on the axisymmetrical theory of elasticity. In the numerical calculations, the thermal stress distributions in the laminated composite finite hollow cylinders are examined. The effects of restrictions at the end of the cylinders on the thermal stress distributions are clarified. The analytical results are compared with the results obtained from the plain strain the ory. It can be seen that the differences in the stresses between the inner cylinder and the outer cylinder increase near the restricted end. The hoop and the axial stresses distribute discontinuously at the interface of the cylinders. The difference in the hoop stress at the interface is minimal in the case of the plain strain theory. For verification, the strains were measured and the analytical results were in fairly good agreement with the experimental results.
{"title":"Axisymmetrical Thermal Stress Analysis of Laminated Composite Finite Hollow Cylinders Restricted at Both Ends in Steady State","authors":"M. Katsuo, T. Sawa, Koji Kawaguchi, H. Kawamura","doi":"10.1115/imece1996-0860","DOIUrl":"https://doi.org/10.1115/imece1996-0860","url":null,"abstract":"\u0000 The thermal stress distributions of laminated composite finite hollow cylinders restricted at both ends and at one end of the cylinders are analyzed using the thermoelastic displacement potential and Michell’s stress functions based on the axisymmetrical theory of elasticity. In the numerical calculations, the thermal stress distributions in the laminated composite finite hollow cylinders are examined. The effects of restrictions at the end of the cylinders on the thermal stress distributions are clarified. The analytical results are compared with the results obtained from the plain strain the ory. It can be seen that the differences in the stresses between the inner cylinder and the outer cylinder increase near the restricted end. The hoop and the axial stresses distribute discontinuously at the interface of the cylinders. The difference in the hoop stress at the interface is minimal in the case of the plain strain theory. For verification, the strains were measured and the analytical results were in fairly good agreement with the experimental results.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82353427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a relative index method is proposed to analyze the nonlinear Von Karman strain effects on the piezoceramic sensored rotor blades. Although other qualitative and quantitative methods are available for nonlinear strain analysis, these methods have inherent drawbacks. For qualitative method the fuzzy terms such as severe, negligible influence, etc., are usually used to describe the effect. The main disadvantage of using these terms is that to different people the same fuzzy word can be interpreted differently. This causes inconsistency which may lead to inaccurate analysis. For quantitative methods, the major disadvantage is that they are unable to delineate the whole picture of the nonlinear effects. However, the proposed relative index method circumvents the drawbacks of both qualitative and quantitative methods. Firstly, it measures the nonlinear effect and converts it into a numerical value. The value is in the range of zero to one in which zero is corresponding to negligible effects and one indicates the highest severity of the nonlinear effects. In addition, to generate the index value this method takes the whole picture of nonlinear effect response into consideration. The results of using the relative index method show that at any given mode of vibration the nonlinear effect on sensor is relatively negligible at high rate of rotation than that on lower ones. The results also indicate that the nonlinear effect is increasing at lower modes of vibration but its effect on sensor almost levels off at higher modes. Moreover, if comparing index value of a given modes of vibration with the index value of its preceding modes, the effect of nonlinearity is decreasing. In addition, the results also suggest that at any given instantaneous speed of rotation the level of the nonlinear effect is diminishing with the higher acceleration/deceleration rate of operation of the blade.
{"title":"Relative Index Method for Nonlinear Strain Analysis of Piezoceramic Sensored Structure","authors":"Y. Lin, T. Lee, D. Saravanos","doi":"10.1115/imece1996-0863","DOIUrl":"https://doi.org/10.1115/imece1996-0863","url":null,"abstract":"\u0000 In this paper, a relative index method is proposed to analyze the nonlinear Von Karman strain effects on the piezoceramic sensored rotor blades. Although other qualitative and quantitative methods are available for nonlinear strain analysis, these methods have inherent drawbacks. For qualitative method the fuzzy terms such as severe, negligible influence, etc., are usually used to describe the effect. The main disadvantage of using these terms is that to different people the same fuzzy word can be interpreted differently. This causes inconsistency which may lead to inaccurate analysis. For quantitative methods, the major disadvantage is that they are unable to delineate the whole picture of the nonlinear effects. However, the proposed relative index method circumvents the drawbacks of both qualitative and quantitative methods. Firstly, it measures the nonlinear effect and converts it into a numerical value. The value is in the range of zero to one in which zero is corresponding to negligible effects and one indicates the highest severity of the nonlinear effects. In addition, to generate the index value this method takes the whole picture of nonlinear effect response into consideration.\u0000 The results of using the relative index method show that at any given mode of vibration the nonlinear effect on sensor is relatively negligible at high rate of rotation than that on lower ones. The results also indicate that the nonlinear effect is increasing at lower modes of vibration but its effect on sensor almost levels off at higher modes. Moreover, if comparing index value of a given modes of vibration with the index value of its preceding modes, the effect of nonlinearity is decreasing. In addition, the results also suggest that at any given instantaneous speed of rotation the level of the nonlinear effect is diminishing with the higher acceleration/deceleration rate of operation of the blade.","PeriodicalId":64773,"journal":{"name":"失效分析与预防","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89400580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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