ASNT 30th Research Symposium Conference Proceedings最新文献

{"title":"Characterization of Additively Manufactured Circular Disks Using Traditional Computed Tomography Volume Segmentation and Machine Learning Algorithms","authors":"J. Miers, D. Moore, B.A. Branch","doi":"10.32548/rs.2022.001","DOIUrl":"https://doi.org/10.32548/rs.2022.001","url":null,"abstract":"Additively manufactured (AM) components contain discontinuities, indications and defects that can change the component’s mechanical performance during high energy impact events. X-ray computed tomography (XCT) reconstructions of AM metastable titanium disks (Ti-5Al-5V-5Mo-3Cr or Ti-5553) were generated on an industrial micro-focus system. Each sample was scanned before and after high velocity impact testing. The porosity resulting from the direct metal laser sintering (DMLS) powder bed fusion machine was detected and characterized. The samples were placed in a gas gun configuration to induce a high-rate tensile load (shock test). The post-test results on the recovered disks contained incipient spall cavities. These features were identified by standard volume segmentation techniques. This inspection data is also evaluated with machine learning (ML) algorithms. A comparison between ML segmentation of the pores/cavities to standard commercial segmentation algorithms will be presented. Improvements using ML were specifically seen in the identification of pores and spall planes in regions of low x-ray attenuation (brightness and contrast). Common XCT artifacts, which include beam hardening and systematic noise, were overcome by the applied ML methods. Porosity and spall plane regions identified by the machine learning analysis were then compared to serial sectioning and scanning electron microscope (SEM) data to judge the precision and accuracy of the machine learning technique. Results show that the CT reconstructed porosity aligned well with the serial sectioned and SEM data. The only discrepancies were in the small pores near the detectability limit and other metrics dependent on the XCT reconstruction resolution.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117171604","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":"Microwave Inspection of Thermal Barrier Coating (TBC) Systems","authors":"A. Case, M.T. Al Qaseer, R. Zoughi","doi":"10.32548/rs.2022.006","DOIUrl":"https://doi.org/10.32548/rs.2022.006","url":null,"abstract":"Nondestructive testing (NDT) of thermal barrier coating (TBC) systems is a critical issue in their manufacturing environments. In particular, inspection techniques by which thickness of TBC topcoat can be accurately determined are currently being sought. This work investigates the use of open-ended rectangular waveguide probes at frequencies in the range of 26.5-70 GHz for evaluation of TBC topcoat thickness. In addition, the influence of volumetric porosity level on thickness measurement accuracy is considered. This investigation encompasses electromagnetic modeling and experimental efforts that are shown to result in the ability to estimate topcoat TBC thickness to within ±1 mil.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"367 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115276216","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":"Melt Pool Temperature Prediction Based on Recurrent Neural Network for Directed Energy Deposition","authors":"Lijie Liu, Weijun Shen, Yiqun Jiang, Xuepeng Jiang, Zhan Zhang, H. Qin, Qing Li","doi":"10.32548/rs.2022.033","DOIUrl":"https://doi.org/10.32548/rs.2022.033","url":null,"abstract":"In directed energy deposition, the melt pool temperature is closely related to the microstructures and defects, thus significantly affecting the final part quality. Multiple factors such as laser power, scanning speed, spot size, and powder feed rate can affect the melt pool temperature profiles. It is critical to determine the melt pool temperature distribution and history during the material deposition. However, the high-energy beam and metal material interaction in the molten pool is a complex coupled process with physical metallurgy changes, which makes it challenging to use the experimental methods to investigate the melt pool temperature distribution under different processing parameters. To address this challenge, we establish two data-driven models using machine learning based on extreme gradient boosting (XGBoost) and long short-term memory (LSTM) correspondingly to predict the melt pool temperature in a thin-wall structure deposition. The experimental results have shown that the prediction of LSTM is sufficiently accurate and fast for in-situ correction. The proposed predictive models are expected to facilitate DED process optimization in melt pool thermal-related properties.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129620784","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":"Effect of Top Layer Coatings on Active Microwave Thermography","authors":"Logan M. Wilcox, K. Donnell","doi":"10.32548/rs.2022.009","DOIUrl":"https://doi.org/10.32548/rs.2022.009","url":null,"abstract":"Active microwave thermography (AMT) is an active thermographic technique that utilizes an electromagnetic-based excitation with infrared measurement of the surface thermal profile of a specimen under test. AMT has been successful utilized in the aerospace and civil infrastructure industries. This work seeks to expand AMT through the investigation of how coatings effect the technique. Results indicate that, dependent on the structure, the thermal contrast can experience different trends, such as linear or logarithmic, when under AMT inspection. This is important as it relates to any AMT investigation that involves a structure that has a coating.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128085301","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":"Numerical Studies on Inclusion and Porosity Imaging for Additive Manufacturing using Full Waveform Inversion","authors":"Shoaib Anwar, Jiaze He, M. Aktharuzzaman, B. Rupp","doi":"10.32548/rs.2022.032","DOIUrl":"https://doi.org/10.32548/rs.2022.032","url":null,"abstract":"Undetected inclusions and porosities in the additive manufactured components are undesirable in industries like aerospace engineering. This paper is focused on imaging of micro inclusions and porosities in numerical models based on the properties of an additive manufactured metal using an advanced imaging technique—full-waveform inversion (FWI) as an ultrasonic non-destructive testing (NDT) technique. We developed three models with—single inclusion of 200µm, multiple inclusions of different sizes (30-200µm) and wave speeds, and multiple porosities (30-100µm). The performance of FWI was analyzed for each model. The reconstructed images of all models from the proposed FWI method gave relatively accurate results about the porosities and inclusions, exhibiting the potential of applying FWI in overcoming challenges in NDT for additively manufactured materials.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128935476","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":"Contact and Non-Contact Resonance Spectroscopy Characterization of Additively Manufactured and Wrought Metallic Samples","authors":"Evan Bozak, J. Rivière, P. Shokouhi","doi":"10.32548/rs.2022.023","DOIUrl":"https://doi.org/10.32548/rs.2022.023","url":null,"abstract":"Nonlinear resonance ultrasound spectroscopy (NRUS) is a growing NDT technique that tracks amplitude-dependent changes in resonance frequency to assess the presence of damage, such as dislocations and micro-cracks [1]. The amount of frequency shift with increasing amplitude is typically quantified with the nonclassical nonlinear parameter f [1]. NRUS has been used in metals to study fatigue damage [2], [3] , creep [4], stress corrosion cracking [5], thermal aging [6]–[8], and porosity [9]. Unlike linear techniques, nonlinear approaches are sensitive to the presence of micro-damage, which is of great interest to uncover early forms of damage, and help setting out adequate maintenance plans. Additionally, resonance approaches enable quick inspection of parts, irrespective of how complex the geometry is. A typical way of conducting NRUS tests is to bond a piezoelectric (PZT) disc to the sample. The PZT is used as a source and allows one to achieve large excitation amplitudes (nonlinear elastic regime with dynamic strain of order ~10-5). Unfortunately, the bond between the sample and the disc introduces additional elastic nonlinearity, and measurements must be repeated several times, with ungluing/regluing of the PZT in-between each test. Moreover, the intrinsic nonlinearity of the sample cannot be determined, and only relative differences in nonlinearity across a set of samples can be examined, that is, only relative measurements can be made. This makes consistent and repeatable measurements difficult to achieve [10]. Being able to conduct NRUS tests in a non-contact fashion would be transformational, making the measurements much faster, more reproducible, and absolute. Recently, air-coupled transducers have been used as an excitation source for NRUS tests on small metallic prismatic specimens [6]–[8], reaching dynamic strains of order ~2×10-6. A “candy can” cavity with multiple PZTs has also been used successfully as an excitation source to conduct nonlinear measurements [11], [12] . The cavity consists of a focusing chamber with an aperture for sample excitation. Combined with a time reversal technique, the cavity achieves higher incident pressure and narrower focus than commercial focused air-coupled transducers [11], [12]. If a high enough excitation can be achieved, it could likely be used as an excitation source for NRUS testing. Pulsed Nd:YAG lasers have also been used as a non-contact excitation source for resonance ultrasound spectroscopy (RUS) [13], [14]. Such laser could be used for NRUS testing as well, in combination with signal processing developed for impact-based NRUS, when a single hammer impact excitation is used for NRUS testing [15]–[17]. The objective of this study is to compare the NRUS parameters of additively manufactured (AM) and wrought cylindrical 316 stainless steel samples with four different heat treatments. We compare the results of four different excitation methods: in-contact piezoelectric discs, air-coupled transduc","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132690782","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":"Towards In-situ Monitoring of Additively Manufactured Parts Using Nonlinear Resonant Acoustic Spectroscopy","authors":"P. Manogharan, J. Rivière, P. Shokouhi","doi":"10.32548/rs.2022.014","DOIUrl":"https://doi.org/10.32548/rs.2022.014","url":null,"abstract":"Additive manufacturing (AM) is rapidly reshaping the manufacturing landscape due to its ability to produce light weight components, complex parts with minimal waste and reduced manufacturing time. However, AM parts may contain various process defects such as porosity, lack of fusion and cracks limiting their industrial applications. The quality of the AM parts needs to be ensured for successful application in various critical industries such as aerospace and biomedical. While nondestructive testing (NDT) is an efficient tool for quality control and process monitoring of the AM parts, existing NDT techniques have limitations. This study investigates the feasibility of using nonlinear resonant acoustic spectroscopy (NRAS) for real-time process control of additively manufactured parts. NRAS is a resonance-based nonlinear acoustic technique widely used to measure the nonlinear hysteretic parameter (𝛼𝛼) of a test material. In NRAS, the test material is excited about its resonance frequency and the linear shift in the resonance frequency with the increasing driving voltage amplitude is measured as the hysteretic nonlinearity. We propose a NRAS test setup for process control of AM parts while they are still attached to the build plate. Several cylindrical AM specimens are tested to measure the hysteretic nonlinearity with and without the build plate for comparison. We observe a systematic decrease in the measured nonlinearity when the specimens are tested on the build plate, which we attribute to the low nonlinearity of the build plate. Despite the observed difference, the measured nonlinearity of the specimens with and without the build plate is highly correlated. With further investigations, the proposed test setup can be potentially used for process monitoring of AM parts in situ.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124093035","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":"In-Situ Optical Tomography for Selective Laser Melting","authors":"Connor Seavers, T. Chu","doi":"10.32548/rs.2022.034","DOIUrl":"https://doi.org/10.32548/rs.2022.034","url":null,"abstract":"Selective laser melting (SLM) has become one of the most common metal additive manufacturing (AM) processes in industries such as medical and aerospace due to its ability to produce highly specialized end-use parts of great complexity. However, current SLM products are prone to process-induced defects, most importantly porosity, which can greatly alter the strength of the part. Therefore, in this study, in-situ monitoring is investigated as a method for detecting the formation of defects during the SLM process. Layerwise optical tomography (OT) images are collected during SLM fabrication of six test samples with planned defects, and subsequently undergo image processing and analysis for identification of anomalous signatures during the build process. The image processing framework employs an average squared difference (ASD) metric to elucidate defects within the image, then feeds the output into an automated k-means clustering algorithm for segmentation and classification. While the k-means classification approach ultimately proved to be sensitive to noise in the images, the image processing workflow was still able to isolate defects, often providing a clear segmentation of the defect in the final output.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114720841","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":"Zero Group Velocity Modes in Rails: a Numerical Study","authors":"Y. Wu, Xuan Zhu, J. Popovics","doi":"10.32548/rs.2022.010","DOIUrl":"https://doi.org/10.32548/rs.2022.010","url":null,"abstract":"Ultrasonic guided wave propagation along a free rail was simulated to understand the existence of intrinsic zero-group velocity (ZGV) modes. A finite element model was established to spatially sample the complex wave disturbance in the rail to study its dispersion relationships. The sharp resonant phenomenon of ZGV modes was observed in the frequency domain, and multiple ZGV points were identified at finite wavenumbers in the wavenumber-frequency domain. The resonances with positive and negative wavenumbers revealed that the observed ZGV modes result from the interference of two propagating modes traveling in opposite directions. ZGV modes in free rails have the potential for rail defect detection, support condition assessment, and stress-free temperature measurement.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130107913","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":"Rail Base Defect Detection via Line Scan Thermography","authors":"Guilherme C. Gandia, J. Winn, Connor Seavers, Anish Poudel, James Mathias, T. Chu","doi":"10.32548/rs.2022.020","DOIUrl":"https://doi.org/10.32548/rs.2022.020","url":null,"abstract":"High-speed, in-motion detection of defects in active railways has become a primary focus in nondestructive testing (NDT) research and development efforts in the rail industry today. This investigation aims to provide further insight regarding the dynamic application of infrared thermography (IRT), namely line-scanning thermography (LST), for the detection of rail-base defects. A 3D finite element analysis (FEA) model was developed to first determine feasible parameters for the experimental setup, then subsequently employed for comparison with experimental results. To perform the experiments, mild steel samples were heated first by passing beneath an IR line heater (2000 W) then immediately observed with an IR camera to capture the thermal response. Results showed that for a thin steel specimen having stepped thickness (3.175 mm, 6.350 mm), a thermal contrast of 4.1ºC could be detected when inspections were performed at ~48.0 mm/s, revealing an agreement of roughly 95% with experimental results. In the case of thick steel samples containing bottom-drilled holes (BDHs), both experimental and analytical results showed that thermal contrasts of ~1ºC could be detected in regions above BDHs. Finally, performing LST on a rail-base sample containing BDHs yielded a contrast of 4.2ºC when moving at 40 mm/s.","PeriodicalId":367504,"journal":{"name":"ASNT 30th Research Symposium Conference Proceedings","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116434113","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}