This contribution gives an overview of the early history of fracture mechanics and highlights the contributions of Karl Wieghardt and Alfons Leon to the development of the basic analytical equations of fracture mechanics.It is shown that the work of these pioneers anticipated many of the later developments by several decades. It will also be shown that particularly the work by Wieghardt was in fact directly related to a practical failure case and the neglect of his fundamental paper is unjustified.
{"title":"Fracture Mechanics: Forgotten German and Austrian Pioneers of the Turn of the 20th Century","authors":"H. Rossmanith","doi":"10.1520/STP13413S","DOIUrl":"https://doi.org/10.1520/STP13413S","url":null,"abstract":"This contribution gives an overview of the early history of fracture mechanics and highlights the contributions of Karl Wieghardt and Alfons Leon to the development of the basic analytical equations of fracture mechanics.It is shown that the work of these pioneers anticipated many of the later developments by several decades. It will also be shown that particularly the work by Wieghardt was in fact directly related to a practical failure case and the neglect of his fundamental paper is unjustified.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"55 1","pages":"347-356"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79849529","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}
A simple TMF facility is described which is capable of 'in-phase', 'out of phase' and 'diamond' type strain-temperature cycling. Typical TMF loops are presented for the 'diamond' type cycle for the nickel-base alloys IN100, Nimonic 90, IN738 and directionally solidified CM247LC-DS over the temperature range 400 °C-1000 °C. Alongside these results, isothermal cyclic stress-strain data are provided for ascending and descending strain amplitudes at discrete temperatures encompassing the strain and temperature range of the TMF tests. Testing on any individual specimen was terminated after a fixed energy consumption. By superimposing the symmetrical isothermal loops about a common origin, the isothermal data are then used to predict the observed (asymmetrical) TMF behaviour. The method works well for materials which show history independence such as IN100. However, for some of the materials, slight modification to the procedure is required. The sensitivity of the method to the form of isothermal data is demonstrated.
{"title":"Modelling Thermo-mechanical Fatigue Hysteresis Loops from Isothermal Cyclic Data","authors":"R. Skelton, G. Webster, B. D. Mestral, C.Y. Wang","doi":"10.1520/STP15254S","DOIUrl":"https://doi.org/10.1520/STP15254S","url":null,"abstract":"A simple TMF facility is described which is capable of 'in-phase', 'out of phase' and 'diamond' type strain-temperature cycling. Typical TMF loops are presented for the 'diamond' type cycle for the nickel-base alloys IN100, Nimonic 90, IN738 and directionally solidified CM247LC-DS over the temperature range 400 °C-1000 °C. Alongside these results, isothermal cyclic stress-strain data are provided for ascending and descending strain amplitudes at discrete temperatures encompassing the strain and temperature range of the TMF tests. Testing on any individual specimen was terminated after a fixed energy consumption. By superimposing the symmetrical isothermal loops about a common origin, the isothermal data are then used to predict the observed (asymmetrical) TMF behaviour. The method works well for materials which show history independence such as IN100. However, for some of the materials, slight modification to the procedure is required. The sensitivity of the method to the form of isothermal data is demonstrated.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"62 1","pages":"69-84"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83436546","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}
{"title":"Test Procedures for Determining the Delamination Toughness of Ceramic Matrix Composites as a Function of Mode Ratio, Temperature, and Layup","authors":"Jonathan J. Polaha, B. Davidson","doi":"10.1520/STP15004S","DOIUrl":"https://doi.org/10.1520/STP15004S","url":null,"abstract":"","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"35 1","pages":"31-47"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89486053","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}
Although polyimide based composites have been used for many years in a wide variety of elevated temperature applications, very little work has been done to examine the durability and damage behavior under more prototypical thermomechanical fatigue (TMF) loadings. Synergistic effects resulting from simultaneous temperature and load cycling can potentially lead to enhanced, if not unique, damage modes and contribute to a number of nonlinear deformation responses. The goal of this research was to examine the effects of a TMF loading spectrum, representative of a gas turbine engine compressor application, on a polyimide sheet molding compound (SMC). High performance SMCs present alternatives to prepreg forms with great potential for low cost component production through less labor intensive, more easily automated manufacturing. To examine the issues involved with TMF, a detailed experimental investigation was conducted to characterize the durability of a T650-35/ PMR-15 SMC subjected to TMF mission cycle loadings. Fatigue damage progression was tracked through macroscopic deformation and elastic stiffness. Additional properties, such as the glass transition temperature (T g ) and dynamic mechanical properties were examined. The fiber distribution orientation was also characterized through a detailed quantitative image analysis. Damage tolerance was quantified on the basis of residual static tensile properties after a prescribed number of TMF missions. Detailed micro-structural examinations were conducted using optical and scanning electron microscopy to characterize the local damage. The imposed baseline TMF missions had only a modest impact on inducing fatigue damage with no statistically significant degradation occurring in the measured macroscopic properties. Micro-structural damage was, however, observed subsequent to 100 h of TMF cycling which consisted primarily of fiber debonding and transverse cracking local to predominantly transverse fiber bundles. The TMF loadings did introduce creep related effects (strain accumulation) which led to rupture in some of the more aggressive stress scenarios examined. In some cases, this creep behavior occurred at temperatures in excess of 150°C below commonly cited values for T g . Thermomechanical exploratory creep tests revealed that the SMC was subject to time dependent deformation at stress/temperature thresholds of 150 MPa/230°C and 170 MPa/180°C.
{"title":"Durability and Damage Tolerance of a Polyimide Chopped Fiber Composite Subjected to Thermomechanical Fatigue Missions and Creep Loadings","authors":"M. Castelli, J. Sutter, D. M. Benson","doi":"10.1520/STP15839S","DOIUrl":"https://doi.org/10.1520/STP15839S","url":null,"abstract":"Although polyimide based composites have been used for many years in a wide variety of elevated temperature applications, very little work has been done to examine the durability and damage behavior under more prototypical thermomechanical fatigue (TMF) loadings. Synergistic effects resulting from simultaneous temperature and load cycling can potentially lead to enhanced, if not unique, damage modes and contribute to a number of nonlinear deformation responses. The goal of this research was to examine the effects of a TMF loading spectrum, representative of a gas turbine engine compressor application, on a polyimide sheet molding compound (SMC). High performance SMCs present alternatives to prepreg forms with great potential for low cost component production through less labor intensive, more easily automated manufacturing. To examine the issues involved with TMF, a detailed experimental investigation was conducted to characterize the durability of a T650-35/ PMR-15 SMC subjected to TMF mission cycle loadings. Fatigue damage progression was tracked through macroscopic deformation and elastic stiffness. Additional properties, such as the glass transition temperature (T g ) and dynamic mechanical properties were examined. The fiber distribution orientation was also characterized through a detailed quantitative image analysis. Damage tolerance was quantified on the basis of residual static tensile properties after a prescribed number of TMF missions. Detailed micro-structural examinations were conducted using optical and scanning electron microscopy to characterize the local damage. The imposed baseline TMF missions had only a modest impact on inducing fatigue damage with no statistically significant degradation occurring in the measured macroscopic properties. Micro-structural damage was, however, observed subsequent to 100 h of TMF cycling which consisted primarily of fiber debonding and transverse cracking local to predominantly transverse fiber bundles. The TMF loadings did introduce creep related effects (strain accumulation) which led to rupture in some of the more aggressive stress scenarios examined. In some cases, this creep behavior occurred at temperatures in excess of 150°C below commonly cited values for T g . Thermomechanical exploratory creep tests revealed that the SMC was subject to time dependent deformation at stress/temperature thresholds of 150 MPa/230°C and 170 MPa/180°C.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"19 1","pages":"285-309"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89208531","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}
Unexpected brittle cracking of welded beam-column connections during the 1994 Northridge earthquake has raised serious concerns about standards and practice for the seismic design and construction of steel moment resisting frames. As part of a nationally coordinated program to investigate the connection damage, finite-element fracture analyses are used to quantify fracture toughness demands in welded beam-column connections as influenced by various detailing parameters. Toughness demands at weld root defects in the beam flange groove welds are quantified in terms of K 1 , CTOD, and CTOA. Summarized are insights concerning the role of finite-element fracture analyses to investigate fracture behavior and the influence of factors such as flaw sizes, weld strengths, inelastic crack growth, and other parameters affecting fracture toughness demands.
{"title":"Finite-Element Fracture Analyses of Welded Beam-Column Connections","authors":"Wei-Ming Chi, G. Deierlein, A. Ingraffea","doi":"10.1520/STP13419S","DOIUrl":"https://doi.org/10.1520/STP13419S","url":null,"abstract":"Unexpected brittle cracking of welded beam-column connections during the 1994 Northridge earthquake has raised serious concerns about standards and practice for the seismic design and construction of steel moment resisting frames. As part of a nationally coordinated program to investigate the connection damage, finite-element fracture analyses are used to quantify fracture toughness demands in welded beam-column connections as influenced by various detailing parameters. Toughness demands at weld root defects in the beam flange groove welds are quantified in terms of K 1 , CTOD, and CTOA. Summarized are insights concerning the role of finite-element fracture analyses to investigate fracture behavior and the influence of factors such as flaw sizes, weld strengths, inelastic crack growth, and other parameters affecting fracture toughness demands.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"54 1","pages":"439-455"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80615314","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 isothermal low-cycle fatigue (LCF) and the out-of-phase thermomechanical fatigue (TMF) behaviours of the directionally solidified nickel-base superalloy DS CM 247 LC, coated with a plasma-sprayed NiCrAlY-coating (PCA-1), were studied in detail. The investigations were performed on the uncoated, the coated substrate material and also on the pure coating material, in contrast to most existing work. The results of the isothermal LCF tests show that the fatigue life of the substrate/coating-composite is governed by the fatigue behaviour of the bulk coating material. The out-of-phase TMF cyclic deformation behaviour of the substrate/coating-composite reflects that of the components and is well described by an isostrain composite model. When the mechanical strain amplitudes experienced by the coating material are plotted against the fatigue life, the data on the coated material in isothermal LCF tests at the upper and lower temperatures of the TMF cycle, respectively, and in the TMF tests coincide. This gives further evidence that the behaviour of the coating materials governs that of the coated composite.
研究了等离子喷涂nicraly涂层(PCA-1)后定向凝固镍基高温合金DS CM 247 LC的等温低周疲劳(LCF)和非相热机械疲劳(TMF)行为。与大多数现有工作不同的是，对未涂覆的基材、涂覆的基材和纯涂层材料进行了研究。等温LCF试验结果表明，基体/涂层复合材料的疲劳寿命受本体涂层材料的疲劳行为支配。基体/涂层复合材料的非相TMF循环变形行为反映了各组分的循环变形行为，可以用等应变复合材料模型很好地描述。将涂层材料所经历的力学应变幅值与疲劳寿命进行对比，发现涂层材料在TMF循环的上、低温下的等温LCF试验数据与TMF试验数据吻合。这进一步证明了涂层材料的行为支配着涂层复合材料的行为。
{"title":"Thermo-mechanical and Isothermal Fatigue of a Coated Columnar-Grained Directionally Solidified Nickel-Base Superalloy","authors":"R. Kowalewski, H. Mughrabi","doi":"10.1520/STP15250S","DOIUrl":"https://doi.org/10.1520/STP15250S","url":null,"abstract":"The isothermal low-cycle fatigue (LCF) and the out-of-phase thermomechanical fatigue (TMF) behaviours of the directionally solidified nickel-base superalloy DS CM 247 LC, coated with a plasma-sprayed NiCrAlY-coating (PCA-1), were studied in detail. The investigations were performed on the uncoated, the coated substrate material and also on the pure coating material, in contrast to most existing work. The results of the isothermal LCF tests show that the fatigue life of the substrate/coating-composite is governed by the fatigue behaviour of the bulk coating material. The out-of-phase TMF cyclic deformation behaviour of the substrate/coating-composite reflects that of the components and is well described by an isostrain composite model. When the mechanical strain amplitudes experienced by the coating material are plotted against the fatigue life, the data on the coated material in isothermal LCF tests at the upper and lower temperatures of the TMF cycle, respectively, and in the TMF tests coincide. This gives further evidence that the behaviour of the coating materials governs that of the coated composite.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"16 1","pages":"3-17"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78860296","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}
{"title":"Micromechanical Modeling of Hydrogen Transport—A Review","authors":"P. Sofronis, A. Taha","doi":"10.1520/STP10215S","DOIUrl":"https://doi.org/10.1520/STP10215S","url":null,"abstract":"","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"51 1","pages":"70-103"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73615212","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}
L. Valoppi, Myrto X Petreas, R. Donohoe, L. Sullivan, C. Callahan
Common analytical methods for detecting and quantifying polychlorinated biphenyls (PCBs) in environmental samples rely on matching a pattern of peaks to a series of Aroclor standards. Due to differences in degradation, partitioning, and metabolism, the PCB pattern in environmental samples can be very different from the Aroclor standards, making identification and quantification of PCBs difficult. To identify an appropriate approach for PCB analyses, the U.S. Environmental Protection Agency Region 9, Biological Technical Assistance Group (BTAG), has considered PCB environmental fate and ecotoxicity, reviewed methods and laboratory capabilities for PCB analysis, and evaluated site-specific data from California and elsewhere. Results of this review indicate analytical methods for routine measurement of specific PCB congeners are currently available, and are cost-effective in comparison with Aroclor-based methods. Accordingly, BTAG has developed a core list of congeners and a phased approach for PCB congener-specific analysis in ecological risk assessments.
{"title":"Use of PCB Congener and Homologue Analysis in Ecological Risk Assessment","authors":"L. Valoppi, Myrto X Petreas, R. Donohoe, L. Sullivan, C. Callahan","doi":"10.1520/STP14420S","DOIUrl":"https://doi.org/10.1520/STP14420S","url":null,"abstract":"Common analytical methods for detecting and quantifying polychlorinated biphenyls (PCBs) in environmental samples rely on matching a pattern of peaks to a series of Aroclor standards. Due to differences in degradation, partitioning, and metabolism, the PCB pattern in environmental samples can be very different from the Aroclor standards, making identification and quantification of PCBs difficult. To identify an appropriate approach for PCB analyses, the U.S. Environmental Protection Agency Region 9, Biological Technical Assistance Group (BTAG), has considered PCB environmental fate and ecotoxicity, reviewed methods and laboratory capabilities for PCB analysis, and evaluated site-specific data from California and elsewhere. Results of this review indicate analytical methods for routine measurement of specific PCB congeners are currently available, and are cost-effective in comparison with Aroclor-based methods. Accordingly, BTAG has developed a core list of congeners and a phased approach for PCB congener-specific analysis in ecological risk assessments.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"24 1","pages":"147-161"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75788824","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}
Thermomechanical fatigue (TMF) is a unique type of fatigue process in which a component is simultaneously subjected to fluctuating loads and temperature. Isothermal life prediction techniques are often not applicable to TMF conditions since mechanical properties are temperature dependent with different damage mechanisms. There are two major cycles in TMF: the in-phase (IP) cycle where the maximum strain peak coincides with the maximum temperature and the out-of-phase (OP) cycle where the maximum strain and the lowest temperature coincide. Experimental and analytical methods are developed to address the effect of thermomechanical strain cycling on coated nickel base superalloy IN-738LC material which is a γ' (Ni 3 Al) strengthened material used primarily for land based gas turbine blades. The coating system was a NiCoCrAlY overlay type. Tubular specimens in the two conditions, coated and uncoated, were primarily tested in out-of-phase (OP) TMF loading with a temperature range of 482-871°C. Using a viscoplastic concept which accounts for strain/temperature cycling response of substrate and coatings in terms of hysteresis loops which characterize the evolution of stress/strain/cycle up to mid-life cycle, a life prediction model was developed incorporating the effect of creep (strain hold-period), environment, and temperature. Test results show the OP TMF type cycle is the most damaging cycle for the coated IN-738LC material when compared to both in-phase and isothermal cycles. All experiments were strain-controlled with a triangular waveform and a strain-ratio A = e a m p /e m e a n = ∞.
热机械疲劳(TMF)是一种独特的疲劳过程，其中一个部件同时受到波动载荷和温度。等温寿命预测技术通常不适用于TMF条件，因为力学性能与温度有关，具有不同的损伤机制。TMF有两个主要周期:最大应变峰与最高温度重合的同相(IP)周期和最大应变峰与最低温度重合的异相(OP)周期。采用实验和分析方法研究了热机械应变循环对镀镍基高温合金IN-738LC材料的影响。IN-738LC材料是一种主要用于陆基燃气轮机叶片的γ′(ni3al)强化材料。涂层系统为NiCoCrAlY覆盖型。管状试样在包覆和未包覆两种条件下，主要在out- phase (OP) TMF加载下进行测试，温度范围为482-871℃。采用粘塑性概念，根据滞回线来解释基底和涂层的应变/温度循环响应，滞回线表征应力/应变/循环直至中期周期的演变，建立了一个包含蠕变(应变保持期)、环境和温度影响的寿命预测模型。测试结果表明，与同相循环和等温循环相比，OP TMF型循环对涂层IN-738LC材料的破坏最大。所有实验均采用三角形波形应变控制，应变比a = e a m p /e me an =∞。
{"title":"Thermo-mechanical Out-of-Phase Fatigue Life of Overlay Coated IN-738LC Gas Turbine Material","authors":"S. Zamrik, M. Renauld","doi":"10.1520/STP15257S","DOIUrl":"https://doi.org/10.1520/STP15257S","url":null,"abstract":"Thermomechanical fatigue (TMF) is a unique type of fatigue process in which a component is simultaneously subjected to fluctuating loads and temperature. Isothermal life prediction techniques are often not applicable to TMF conditions since mechanical properties are temperature dependent with different damage mechanisms. There are two major cycles in TMF: the in-phase (IP) cycle where the maximum strain peak coincides with the maximum temperature and the out-of-phase (OP) cycle where the maximum strain and the lowest temperature coincide. Experimental and analytical methods are developed to address the effect of thermomechanical strain cycling on coated nickel base superalloy IN-738LC material which is a γ' (Ni 3 Al) strengthened material used primarily for land based gas turbine blades. The coating system was a NiCoCrAlY overlay type. Tubular specimens in the two conditions, coated and uncoated, were primarily tested in out-of-phase (OP) TMF loading with a temperature range of 482-871°C. Using a viscoplastic concept which accounts for strain/temperature cycling response of substrate and coatings in terms of hysteresis loops which characterize the evolution of stress/strain/cycle up to mid-life cycle, a life prediction model was developed incorporating the effect of creep (strain hold-period), environment, and temperature. Test results show the OP TMF type cycle is the most damaging cycle for the coated IN-738LC material when compared to both in-phase and isothermal cycles. All experiments were strain-controlled with a triangular waveform and a strain-ratio A = e a m p /e m e a n = ∞.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"58 1","pages":"119-137"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85221311","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}
This paper describes research to determine the influence of multiple-site damage on the fatigue life of lap joint specimens. Multiple-site damage is an important concern in aging aircraft and deals with determining failure conditions for multiple crack configurations. The goal of this paper is to determine the fatigue life for a mechanically fastened joint with multiple fatigue cracks located along one row of rivet holes. A predictive model for the fatigue life is evaluated with the results of several precracked specimens tested to failure under constant amplitude loading. Predictions for the growth and coalescence of individual cracks in specimens with various initial crack configurations and applied stress levels agree well with the experimental results.
{"title":"Fatigue Analysis of Multiple Site Damage in Lap Joint Specimens","authors":"Hsing-Ling Wang, A. Grandt","doi":"10.1520/STP13405S","DOIUrl":"https://doi.org/10.1520/STP13405S","url":null,"abstract":"This paper describes research to determine the influence of multiple-site damage on the fatigue life of lap joint specimens. Multiple-site damage is an important concern in aging aircraft and deals with determining failure conditions for multiple crack configurations. The goal of this paper is to determine the fatigue life for a mechanically fastened joint with multiple fatigue cracks located along one row of rivet holes. A predictive model for the fatigue life is evaluated with the results of several precracked specimens tested to failure under constant amplitude loading. Predictions for the growth and coalescence of individual cracks in specimens with various initial crack configurations and applied stress levels agree well with the experimental results.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"52 1","pages":"214-226"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85556998","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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