Economic bridge management requires accurate information about the condition of bridges in the network. Nondestructive evaluation (NDE)has shown high potential in providing accurate condition assessment and, through periodic surveys, development of accurate deterioration, predictive, and life-cycle cost models. To achieve wide adoption by transportation agencies, further advances should be made that would lead to the accuracy of NDE-based condition assessment, reduced costs and traffic interruptions, and minimized risk to transportation workers. The paper discusses the following areas of improvement: increased speed and safety of data collection through the use of robotic systems, and improved data interpretation through visualization and joint analysis of data collected by multiple NDE technologies.
{"title":"Advancing Condition Assessment of Reinforced Concrete Bridge Elements Through Automation, Visualization, and Improved Interpretation of Multi-NDE Technology Data","authors":"","doi":"10.32548/2023.me-04289","DOIUrl":"https://doi.org/10.32548/2023.me-04289","url":null,"abstract":"Economic bridge management requires accurate information about the condition of bridges in the network. Nondestructive evaluation (NDE)has shown high potential in providing accurate condition assessment and, through periodic surveys, development of accurate deterioration, predictive, and life-cycle cost models. To achieve wide adoption by transportation agencies, further advances should be made that would lead to the accuracy of NDE-based condition assessment, reduced costs and traffic interruptions, and minimized risk to transportation workers. The paper discusses the following areas of improvement: increased speed and safety of data collection through the use of robotic systems, and improved data interpretation through visualization and joint analysis of data collected by multiple NDE technologies.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48393608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Drones are increasingly used during routine inspections of bridges to improve data consistency, work efficiency, inspector safety, and cost effectiveness. Most drones, however, are operated manually within a visual line of sight and thus unable to inspect long-span bridges that are not completely visible to operators. In this paper, aerial nondestructive evaluation (aNDE) will be envisioned for elevated structures such as bridges, buildings, dams, nuclear power plants, and tunnels. To enable aerial nondestructive testing (aNDT), a human-robot system will be created to integrate haptic sensing and dexterous manipulation into a drone or a structural crawler in augmented/virtual reality (AR/VR) for beyond-visual-line-of-sight (BVLOS) inspection of bridges. Some of the technical challenges and potential solutions associated with aNDT&E will be presented. Example applications of the advanced technologies will be demonstrated in simulated bridge decks with stipulated conditions. The developed human-robot system can transform current on-site inspection to future tele-inspection, minimizing impact to traffic passing over the bridges. The automated tele-inspection can save as much as 75% in time and 95% in cost.
{"title":"Aerial Nondestructive Testing and Evaluation (aNDT&E)","authors":"Ge-wei Chen, Liujun Li, Zhenhua Shi, Bo Shang","doi":"10.32548/2023.me-04300","DOIUrl":"https://doi.org/10.32548/2023.me-04300","url":null,"abstract":"Drones are increasingly used during routine inspections of bridges to improve data consistency, work efficiency, inspector safety, and cost effectiveness. Most drones, however, are operated manually within a visual line of sight and thus unable to inspect long-span bridges that are not completely visible to operators. In this paper, aerial nondestructive evaluation (aNDE) will be envisioned for elevated structures such as bridges, buildings, dams, nuclear power plants, and tunnels. To enable aerial nondestructive testing (aNDT), a human-robot system will be created to integrate haptic sensing and dexterous manipulation into a drone or a structural crawler in augmented/virtual reality (AR/VR) for beyond-visual-line-of-sight (BVLOS) inspection of bridges. Some of the technical challenges and potential solutions associated with aNDT&E will be presented. Example applications of the advanced technologies will be demonstrated in simulated bridge decks with stipulated conditions. The developed human-robot system can transform current on-site inspection to future tele-inspection, minimizing impact to traffic passing over the bridges. The automated tele-inspection can save as much as 75% in time and 95% in cost.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49421755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The primary intent of bridge inspection is safety. Thus, the focus during the initial development of bridge inspection guidelines, including National Bridge Inspection Standards (NBIS), was on making sure structures are safe for the traveling public. NBIS are mandated by federal statute at 23 U.S.C. 144 and implemented under 23 CFR 650 subpart C. Most changes since the inception of NBIS have been due to failures, but recently the focus has shifted to include bridge/ asset management. As such, there has been an increased emphasis on using inspection data for bridge management purposes and on preservation to make sure these structures are not only safe but also can be maintained cost-effectively to minimize life cycle costs. This requires shifting the focus from predominantly visual inspection to supplementing visual inspections with advanced technologies. In this paper, the authors discuss the changes that have occurred since their 2009 Materials Evaluation article.
{"title":"Bridge Inspection – Progression of Bridge Inspection Toward Preservation and Corrosion Mitigation for Improving Asset Management","authors":"Sreevivas Alampalli, F. Jalinoos, Raj Ailaney","doi":"10.32548/2023.me-04292","DOIUrl":"https://doi.org/10.32548/2023.me-04292","url":null,"abstract":"The primary intent of bridge inspection is safety. Thus, the focus during the initial development of bridge inspection guidelines, including National Bridge Inspection Standards (NBIS), was on making sure structures are safe for the traveling public. NBIS are mandated by federal statute at 23 U.S.C. 144 and implemented under 23 CFR 650 subpart C. Most changes since the inception of NBIS have been due to failures, but recently the focus has shifted to include bridge/ asset management. As such, there has been an increased emphasis on using inspection data for bridge management purposes and on preservation to make sure these structures are not only safe but also can be maintained cost-effectively to minimize life cycle costs. This requires shifting the focus from predominantly visual inspection to supplementing visual inspections with advanced technologies. In this paper, the authors discuss the changes that have occurred since their 2009 Materials Evaluation article.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46362986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quality control and quality assurance during construction is vital to ensure the structure is built as designed and durable. For reinforced concrete (RC) structures, rebar diameter, spacing, and concrete cover depth are critical in ensuring that the structure is designed for adequate strength and can maintain its service life without unplanned interventions. Once the rebar is laid out in the field, construction inspectors do the required quality control to ensure that the constructed rebar mat matches the design documents. The checks are made at finite points and thus can be improved with currently available technologies such as LiDAR, augmented reality (AR), and uncrewed aerial vehicles (UAVs). This paper summarizes the available technologies for such an effort and focuses on using Red Blue Green Depth (RGBD) cameras as a quality control tool for construction inspection of RC structures such as buildings and bridges. A study conducted using an RGBD camera for estimating rebar diameter is presented in this paper. Results show that RGBD cameras have a very high potential as a low-cost, efficient tool for quality control of RC structures during construction. RGBD cameras can potentially augment current visual inspections in assuring the structures are built as per design drawings, meeting the appropriate specifications with acceptable accuracy.
{"title":"Automated Geometric Quality Inspection of Rebar Layout using RGBD Data","authors":"Mahsa Sanei, Xinxing Yuan, F. Moreu, S. Alampalli","doi":"10.32548/2023.me-04307","DOIUrl":"https://doi.org/10.32548/2023.me-04307","url":null,"abstract":"Quality control and quality assurance during construction is vital to ensure the structure is built as designed and durable. For reinforced concrete (RC) structures, rebar diameter, spacing, and concrete cover depth are critical in ensuring that the structure is designed for adequate strength and can maintain its service life without unplanned interventions. Once the rebar is laid out in the field, construction inspectors do the required quality control to ensure that the constructed rebar mat matches the design documents. The checks are made at finite points and thus can be improved with currently available technologies such as LiDAR, augmented reality (AR), and uncrewed aerial vehicles (UAVs). This paper summarizes the available technologies for such an effort and focuses on using Red Blue Green Depth (RGBD) cameras as a quality control tool for construction inspection of RC structures such as buildings and bridges. A study conducted using an RGBD camera for estimating rebar diameter is presented in this paper. Results show that RGBD cameras have a very high potential as a low-cost, efficient tool for quality control of RC structures during construction. RGBD cameras can potentially augment current visual inspections in assuring the structures are built as per design drawings, meeting the appropriate specifications with acceptable accuracy.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46344973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Underwater engineering evaluations of transportation assets have historically relied largely upon conventional, crewed commercial diving operations, using visual testing (VT) and tactile examination methods to detect surface discontinuities and evaluate site conditions. In practical application, this approach alone is often found to be suboptimal, due to multiple challenges inherent in conducting inspections in the underwater environment. Modern underwater inspections are increasingly reliant upon new technologies, and nondestructive testing methods beyond VT are used during conventional diving inspection to gain a broader picture of the asset and its condition, increasing efficiency while lowering risk in the process. Underwater engineering inspectors today employ traditional nondestructive technologies, including VT, ultrasonic testing (UT), and magnetic particle testing (MT) techniques, in concert with acoustic (sonar) imaging techniques and remotely operated vehicles (ROVs) to obtain more detailed information about the asset and adjacent waterway conditions. This approach enhances the inspection’s safety and efficiency and reduces risk to the bridge owner and end user. This article discusses today’s underwater bridge inspection approach, emphasizing the NDT technologies utilized and their benefits.
{"title":"Underwater Inspection of Highway Bridges - Recent Trends and Technologies","authors":"David Severns","doi":"10.32548/2023.me-04299","DOIUrl":"https://doi.org/10.32548/2023.me-04299","url":null,"abstract":"Underwater engineering evaluations of transportation assets have historically relied largely upon conventional, crewed commercial diving operations, using visual testing (VT) and tactile examination methods to detect surface discontinuities and evaluate site conditions. In practical application, this approach alone is often found to be suboptimal, due to multiple challenges inherent in conducting inspections in the underwater environment. Modern underwater inspections are increasingly reliant upon new technologies, and nondestructive testing methods beyond VT are used during conventional diving inspection to gain a broader picture of the asset and its condition, increasing efficiency while lowering risk in the process. Underwater engineering inspectors today employ traditional nondestructive technologies, including VT, ultrasonic testing (UT), and magnetic particle testing (MT) techniques, in concert with acoustic (sonar) imaging techniques and remotely operated vehicles (ROVs) to obtain more detailed information about the asset and adjacent waterway conditions. This approach enhances the inspection’s safety and efficiency and reduces risk to the bridge owner and end user. This article discusses today’s underwater bridge inspection approach, emphasizing the NDT technologies utilized and their benefits.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47567149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Probability of detection (POD) studies for evaluating the capabilities of an inspection system for Air Force aircraft structural components commonly use a Logistic Regression model with a Wald 95% confidence interval. However, hit/miss POD data is distributed as a Binomial, and the sample sizes are commonly too small for Wald’s identically and independently normality distributed assumption to be true. This paper uses a large set of simulated representative hit/miss data to compare and contrast the performance of the four confidence intervals methods: Standard Wald, Modified Wald, Profile Likelihood Ratio, and Profile Modified Likelihood Ratio. Performance is measured in terms of bias and existence of a90/95 with respect to data distribution, sample size, overlap, and evenness. This paper provides guidance and methodology on new POD methods that more reliably and accurately estimate a90/95.
{"title":"Confidence Interval Comparisons For Probability of Detection On Hit/Miss Data","authors":"Christine E. Knott, C. S. Kabban","doi":"10.32548/2022.me-04273","DOIUrl":"https://doi.org/10.32548/2022.me-04273","url":null,"abstract":"Probability of detection (POD) studies for evaluating the capabilities of an inspection system for Air Force aircraft structural components commonly use a Logistic Regression model with a Wald 95% confidence interval. However, hit/miss POD data is distributed as a Binomial, and the sample sizes are commonly too small for Wald’s identically and independently normality distributed assumption to be true. This paper uses a large set of simulated representative hit/miss data to compare and contrast the performance of the four confidence intervals methods: Standard Wald, Modified Wald, Profile Likelihood Ratio, and Profile Modified Likelihood Ratio. Performance is measured in terms of bias and existence of a90/95 with respect to data distribution, sample size, overlap, and evenness. This paper provides guidance and methodology on new POD methods that more reliably and accurately estimate a90/95.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44885932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To characterize the capability of an inspection system, indications from the system must be collected over a range of defect sizes. For flaw indications, insufficient sample size, overlap, or evenness between hit and miss indications may cause the probability of detection (POD) estimations to not exist or have high bias. Extensive simulations of representative Lognormal, Weibull, and Uniformly distributed data at varying levels of overlap, evenness, and sample size were fit using four modeling techniques: logistic regression, Firth’s Bias Adjusted Likelihood, the Lasso, and a ranked set sampling method from nonparametric statistics. Profile likelihood ratio confidence intervals were used instead of the standard Wald method to calculate a90/95. The probability of existence and the percent bias of the estimates provide recommendations for the ideal levels of overlap, evenness, modeling technique, and sample size requirements when designing a hit/miss POD study.
{"title":"Modern Design and Analysis For Hit/Miss Probability of Detection Studies Using Profile Likelihood Ratio Confidence Intervals","authors":"Christine E. Knott, C. S. Kabban","doi":"10.32548/2022.me-04272","DOIUrl":"https://doi.org/10.32548/2022.me-04272","url":null,"abstract":"To characterize the capability of an inspection system, indications from the system must be collected over a range of defect sizes. For flaw indications, insufficient sample size, overlap, or evenness between hit and miss indications may cause the probability of detection (POD) estimations to not exist or have high bias. Extensive simulations of representative Lognormal, Weibull, and Uniformly distributed data at varying levels of overlap, evenness, and sample size were fit using four modeling techniques: logistic regression, Firth’s Bias Adjusted Likelihood, the Lasso, and a ranked set sampling method from nonparametric statistics. Profile likelihood ratio confidence intervals were used instead of the standard Wald method to calculate a90/95. The probability of existence and the percent bias of the estimates provide recommendations for the ideal levels of overlap, evenness, modeling technique, and sample size requirements when designing a hit/miss POD study.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44095052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Probability of detection (POD) evaluation is a widely accepted practice for quantifying the reliability of a nondestructive testing (NDT) technique. Inspections are often conceptualized and developed in laboratory environments, where factors affecting the inspection are highly controlled. However, when implemented in practice, NDT inspections suffer from many sources of variability, including changes from nominal geometry of the test piece, sensor variability, differences between operators, environmental effects on the sensor response including thermal and electromagnetic interference, and a myriad of other factors that are not present in the lab. Thus, to transition the NDT from the lab to production environments, engineers must have a quantified understanding of uncertainties. This is especially true for NDT systems that are implemented for safety-critical structures, where the life of the component may be managed with NDT. A fundamental question that must be answered in this context is: What is the largest discontinuity that could be missed when this NDT technique is implemented?
{"title":"What Is Probability of Detection?","authors":"M. Cherry, Christine E. Knott","doi":"10.32548/2022.me-04324","DOIUrl":"https://doi.org/10.32548/2022.me-04324","url":null,"abstract":"Probability of detection (POD) evaluation is a widely accepted practice for quantifying the reliability of a nondestructive testing (NDT) technique. Inspections are often conceptualized and developed in laboratory environments, where factors affecting the inspection are highly controlled. However, when implemented in practice, NDT inspections suffer from many sources of variability, including changes from nominal geometry of the test piece, sensor variability, differences between operators, environmental effects on the sensor response including thermal and electromagnetic interference, and a myriad of other factors that are not present in the lab. Thus, to transition the NDT from the lab to production environments, engineers must have a quantified understanding of uncertainties. This is especially true for NDT systems that are implemented for safety-critical structures, where the life of the component may be managed with NDT. A fundamental question that must be answered in this context is: What is the largest discontinuity that could be missed when this NDT technique is implemented?","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41454340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Siyuan Fang, Xiaowan Zheng, Bicheng Guo, Danielle Zen, Lianxiang Yang
Composite materials are widely used in engineering because of their high strength, high modulus, and corrosion resistance. Accurately obtaining the mechanical properties of composites is helpful for their further development. However, in a uniaxial tensile test, the strain distribution between the front and back of the composite sheet sample may differ due to its heterogeneity, and its stress-strain curve depends on which side the strain is measured. To report the stress-strain curve more accurately, a multicamera digital image correlation (DIC) system was employed to measure the double-sided strain in this work. Two sets of 3D digital image correlation (3D-DIC) systems were placed in front of and behind the specimen to record the tensile process of the specimen, and a double-sided calibration technique was implemented to connect the two sets of 3D-DIC systems into a unified coordinate system. Young’s modulus, percent bending, and local strain history are analyzed based on the measurements of strain on both sides. The results show that the strain on both sides of the composite is not exactly same, especially in the strain concentration area. As a comparison, the strain distribution on both sides of the metal material is almost identical.
{"title":"Experimental Investigation of Double-Sided Strain of Composites in Tensile Testing Using MultiCamera DIC","authors":"Siyuan Fang, Xiaowan Zheng, Bicheng Guo, Danielle Zen, Lianxiang Yang","doi":"10.32548/2022.me-04283","DOIUrl":"https://doi.org/10.32548/2022.me-04283","url":null,"abstract":"Composite materials are widely used in engineering because of their high strength, high modulus, and corrosion resistance. Accurately obtaining the mechanical properties of composites is helpful for their further development. However, in a uniaxial tensile test, the strain distribution between the front and back of the composite sheet sample may differ due to its heterogeneity, and its stress-strain curve depends on which side the strain is measured. To report the stress-strain curve more accurately, a multicamera digital image correlation (DIC) system was employed to measure the double-sided strain in this work. Two sets of 3D digital image correlation (3D-DIC) systems were placed in front of and behind the specimen to record the tensile process of the specimen, and a double-sided calibration technique was implemented to connect the two sets of 3D-DIC systems into a unified coordinate system. Young’s modulus, percent bending, and local strain history are analyzed based on the measurements of strain on both sides. The results show that the strain on both sides of the composite is not exactly same, especially in the strain concentration area. As a comparison, the strain distribution on both sides of the metal material is almost identical.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46524726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Environmental barrier coatings (EBCs) are used as a coating material on fiber-reinforced ceramic matrix composites (CMC) for various aerospace and turbine engines applications. In order to validate physics-based analytical models for predicting the spallation life of EBCs, the fracture strength of the EBC and the kinetics of crack growth in EBC layers need to be experimentally determined under engine operating conditions. In this study, a coating layer of barium strontium aluminum silicate (BSAS)–based melt-infiltrated silicon carbide fiber-reinforced silicon carbide matrix composite (MI SiC/SiC) is applied on a CMC specimen and tensile tested at room temperature. Multiple tests are performed on a single specimen with increasing predetermined stress levels until final failure. Damage progression due to the load applied is monitored using a digital image correlation (DIC) system. After unloading from the predetermined stress levels, the specimen is evaluated by optical microscopy and computed tomography (CT). The inspection forms the imaging which implied that primary and secondary cracks developed during tensile loading until failure. DIC showed formation of a primary crack at ~50% of the ultimate tensile strength, and this crack grew with increasing stress and eventually led to final failure of the specimen.
{"title":"Damage Monitoring of Ceramic Matrix Composites Under Tension Loading Via NDE-based DIC Approach","authors":"A. Abdul-Aziz","doi":"10.32548/2022.me-04296","DOIUrl":"https://doi.org/10.32548/2022.me-04296","url":null,"abstract":"Environmental barrier coatings (EBCs) are used as a coating material on fiber-reinforced ceramic matrix composites (CMC) for various aerospace and turbine engines applications. In order to validate physics-based analytical models for predicting the spallation life of EBCs, the fracture strength of the EBC and the kinetics of crack growth in EBC layers need to be experimentally determined under engine operating conditions. In this study, a coating layer of barium strontium aluminum silicate (BSAS)–based melt-infiltrated silicon carbide fiber-reinforced silicon carbide matrix composite (MI SiC/SiC) is applied on a CMC specimen and tensile tested at room temperature. Multiple tests are performed on a single specimen with increasing predetermined stress levels until final failure. Damage progression due to the load applied is monitored using a digital image correlation (DIC) system. After unloading from the predetermined stress levels, the specimen is evaluated by optical microscopy and computed tomography (CT). The inspection forms the imaging which implied that primary and secondary cracks developed during tensile loading until failure. DIC showed formation of a primary crack at ~50% of the ultimate tensile strength, and this crack grew with increasing stress and eventually led to final failure of the specimen.","PeriodicalId":49876,"journal":{"name":"Materials Evaluation","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43791443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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