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X-ray computed tomography for failure analysis
NDT Abstracts X-ray computerized tornography with spatial resolution of a few tens of micrometers and high contrast resolution offers new possibilities for the detection of shrinkage cracks and incomplete wetting of the contact surfaces in soldered metal --ceramic joints, of crack growth due to bending tests, the determination of the material in small inclusions and the resolution of density gradients in the neighbourhood of voids in ceramic materials. 53990
Bossi, R.; Crews, a.; Georgeson, G.; Nelson, J.; Shrader,
J. X-ray computed tomography for geometry acquisition Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19-24 Jul. 1992. Vol. 12A, pp. 343-349. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1993). ISBN 0-306 A.A.483-6. Computed tomography provides measurements of both external and internal features. Ergonomic, aesthetic and aerodynamically shaped parts, as well as parts for which drawings are unavailable, benefit from the process. Although data reduction and transfer can be performed by computer routines, engineering judgement is very important in the evaluation of the model on the CAE/D system. The engineer can reduce the data sets into simple models by choosing appropriate straight lines, radii and splines to fit to the piece-wise linear strings provided from CT. Also, engineering judgement is used to select the correct orientation of cross sectional plane data, and to eliminate artifacts from the data. Cost savings using CT have been found to be significant over other approaches for the geometry acquisition for complex objects that are suitable for CT examination.
Rummel, W.D.; Davis, M.; Garcia, R. Computed tomography applications in turbine engine overhaul 53989
Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19-24 Jul. 1992. Vol. 12A, pp. 351-355. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1993). ISBN 0-306-44483-6. The United States Air Force has an initiative for technology development and implementation in design, production, acceptance and maintenance overhaul operations. As a part of this initiative, an X- ray computed tomography capability was acquired for use in the support of aircraft structures and gas turbine engine overhaul. A task was initiated to interface the output from the computed tomography (CT) system to an "Automated Nondestructive Evaluation System" (ANDES) to provide a user driven information extraction and decision processing capability for use on nondestructive evaluation (NDE) data. Pre- screening and data interface to a defined format are required as inputs to the ANDES system. Since data from the CT system are provided in a reconstructed image form, an image processing/information extraction capability was required to provide the interface link to the ANDES system. A neural network tool was selected to provide an adaptable pattern recognition and data extraction tool as a primary interface to the ANDES system. This paper describes work in progress to build the neural network interface tool and to integrate the tool into the ANDES system. 53716 Bossi, R~I.; Cline, J.L.; Georgeson, G.E. High resolution computed tomography Boeing Aerospace and Electronics Co., Seattle, Washington, D.C. (United States), AD-A259 728/4/GAR, 39 pp. (31 Jul. 1992) High resolution (greater than 4 line pairs per millimeter) computed tomngraphy (CT) has been studied for its potential use for engineering evaluation of aerospace components. The CT images provide two dimensional maps of material linear X-ray attenuation coefficients for small volume elements, smaller than 0.001 cubic millimeters. These images are similar to micrographic images of polished surfaces from sectioned components, but are achieved nondestructively. 53715 Crews, A.R.; Bossi, R.H. X-ray computed tomography for whole system evaluation (small engines) Boeing Defense and Space Group, Seattle, Washington, D.C. (United States), AD-A259 519/7/GAR, 52 pp. (31 May 1992) CT evaluation has been employed on small jet engines demonstrating its viability for assembly verification, dimensional profiles, and foreign object detection without assembly, CT systems with energies of 400 kV, 2 MV, 2.5 MV and 9MV were used in the study. The sensitivity to feature details in complex systems, such as the jet engines, is improved with higher signal to noise for the same inherent resolution. For long metal paths, the highest energy available is preferred, however many of the 2 MV images showed good sensitivity to internal details, and even 400 kV can be usefully employed in some regions of an engine. The quantitative capability of CT to measure the relative X- ray linear attenuation coefficient and position of small volume elements in an object offers the potential to directly calculate
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the center-of-gravity (CG) of the object from the CT scan data. Results of CT tests on a test phantom indicates that under certain conditions CG calculations can be made for CT data with sensitivity on the order of 0.15 g-cm in aluminum at 3 cm radius. 53714 Georgeson, G.; Bossi, R. X-ray computed tomography for advanced materials and processes Boeing Defense and Space Group, Seattle, Washington, D.C. (United States), AD-A259 828/2/GAR, 56 pp. (30 Jun. 1992) Due to demanding requirements imposed on current and future highperformance aerospace structures, advanced materials are being developed for an used in a variety of aircraft/aerospace applications. Production costs for advanced materials are generally higher and the payback will be greater for data leading to, faster decision making or improvement in the product. The evaluation capability of CT overcomes the limitation of current qualitative inspection techniques to provide an objective measure of material or component condition. The results of studies involving CT testing of various advanced materials manufacturing processes and joining methods revealed four specific areas in which there is potential for significant economic benefit from CT. 53712 Georgeson,G.E.; Crews, A.R.: Bossi, R.H. X-ray computed tomography for casting development Boeing Defense and Space Group, Seattle, Washington (United States), AD-A261 786/8/GAR, 52 pp. (Sep. 1992) Computed tomngraphy (CT) has been used to evaluate specific sand casting product examples for technical and economic benefits. The areas which would benefit include internal dimensional measurements (eliminating destructive sectioning), specific region inspections, flaw characterization in critical regions (to allow passing or informed repair of castings), and geometric acquisition for CAD/CAM. 53711 Bossi,R.H.; Crews, A.R.; Georgeson, G.E. X-ray computed tomography for failure analysis Boeing Defense and Space Group, Seattle, Washington (United States), AD-A261 884/I/GAR, 56 pp. (Aug. 1992) Under a preliminary testing task assignment of the Advanced Development of X-ray Computed Tomngraphy Application program, computed tomography (CT) has been studied for its potential as a tool to assist in failure analysis investigations. CT provides three-dimensional spatial distribution of material that can be used to assess internal configurations and material conditions nondestructively. This capability has been used in failure analysis studies to determine the position of internal components and their operation. CT is particularly advantageous on complex systems, composite failure studies, and testing under operational or environmental conditions. CT plays an important role in reducing the time and effort of a failure analysis investigation. 53511 Drake,S.G. Improved real-time x-ray technology widens the horizons of industrial computer tomography British Journal of Non-Destructive Testing, Vol. 35, No. 10, pp. 580- 83 (Oct. 1993) As a result of collaboration between OIS Engineering and the National NDT Centre (NNDTC), Harwell, two new computer tomography systems have been recently developed. The f'wst provides for high definition, microfocal CT down to five microns resolution, whilst the second was used for the in-field inspection of wooden power transmission poles at ground level. 53509 Stinson,M.C.; Holloway, D.A.; Ellingson, W.A. Quantification of volume flaw sizes in ceramics by image processing of 3D x-ray tomographic d a t a sets Ceramic Engineering and Science Proceedings, Vol. 14, No. 7-8, pp. 485- 491 (Jul.-Aug. 1993) This paper introduces a technique to quantify internal flaws in a ceramic body. The approach uses data images obtained from 3D X-ray computed tomography. An approach called guided segmentation uses image processing methods applied to a series of the data images to quantify the flaw volumes. The technique is tested on synthesized data for spheres. The technique is then applied to real images of known size to examine its use. 53507 Quinto,E.T. Computed tomography and rockets Conference on Math Methods in Tomography, Oberwolfach (Germany), 5-11 Jun. 1990. pp. 261-268. Springer-Verlag (1991) We describe our exterior reconstruction algorithm that reconstructs the outer shell of an object using only X-ray tomographic data that passes
Bossi, R.; Crews, a.; Georgeson, G.; Nelson, J.; Shrader,
J. X-ray computed tomography for geometry acquisition Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19-24 Jul. 1992. Vol. 12A, pp. 343-349. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1993). ISBN 0-306 A.A.483-6. Computed tomography provides measurements of both external and internal features. Ergonomic, aesthetic and aerodynamically shaped parts, as well as parts for which drawings are unavailable, benefit from the process. Although data reduction and transfer can be performed by computer routines, engineering judgement is very important in the evaluation of the model on the CAE/D system. The engineer can reduce the data sets into simple models by choosing appropriate straight lines, radii and splines to fit to the piece-wise linear strings provided from CT. Also, engineering judgement is used to select the correct orientation of cross sectional plane data, and to eliminate artifacts from the data. Cost savings using CT have been found to be significant over other approaches for the geometry acquisition for complex objects that are suitable for CT examination.
Rummel, W.D.; Davis, M.; Garcia, R. Computed tomography applications in turbine engine overhaul 53989
Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19-24 Jul. 1992. Vol. 12A, pp. 351-355. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1993). ISBN 0-306-44483-6. The United States Air Force has an initiative for technology development and implementation in design, production, acceptance and maintenance overhaul operations. As a part of this initiative, an X- ray computed tomography capability was acquired for use in the support of aircraft structures and gas turbine engine overhaul. A task was initiated to interface the output from the computed tomography (CT) system to an "Automated Nondestructive Evaluation System" (ANDES) to provide a user driven information extraction and decision processing capability for use on nondestructive evaluation (NDE) data. Pre- screening and data interface to a defined format are required as inputs to the ANDES system. Since data from the CT system are provided in a reconstructed image form, an image processing/information extraction capability was required to provide the interface link to the ANDES system. A neural network tool was selected to provide an adaptable pattern recognition and data extraction tool as a primary interface to the ANDES system. This paper describes work in progress to build the neural network interface tool and to integrate the tool into the ANDES system. 53716 Bossi, R~I.; Cline, J.L.; Georgeson, G.E. High resolution computed tomography Boeing Aerospace and Electronics Co., Seattle, Washington, D.C. (United States), AD-A259 728/4/GAR, 39 pp. (31 Jul. 1992) High resolution (greater than 4 line pairs per millimeter) computed tomngraphy (CT) has been studied for its potential use for engineering evaluation of aerospace components. The CT images provide two dimensional maps of material linear X-ray attenuation coefficients for small volume elements, smaller than 0.001 cubic millimeters. These images are similar to micrographic images of polished surfaces from sectioned components, but are achieved nondestructively. 53715 Crews, A.R.; Bossi, R.H. X-ray computed tomography for whole system evaluation (small engines) Boeing Defense and Space Group, Seattle, Washington, D.C. (United States), AD-A259 519/7/GAR, 52 pp. (31 May 1992) CT evaluation has been employed on small jet engines demonstrating its viability for assembly verification, dimensional profiles, and foreign object detection without assembly, CT systems with energies of 400 kV, 2 MV, 2.5 MV and 9MV were used in the study. The sensitivity to feature details in complex systems, such as the jet engines, is improved with higher signal to noise for the same inherent resolution. For long metal paths, the highest energy available is preferred, however many of the 2 MV images showed good sensitivity to internal details, and even 400 kV can be usefully employed in some regions of an engine. The quantitative capability of CT to measure the relative X- ray linear attenuation coefficient and position of small volume elements in an object offers the potential to directly calculate
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the center-of-gravity (CG) of the object from the CT scan data. Results of CT tests on a test phantom indicates that under certain conditions CG calculations can be made for CT data with sensitivity on the order of 0.15 g-cm in aluminum at 3 cm radius. 53714 Georgeson, G.; Bossi, R. X-ray computed tomography for advanced materials and processes Boeing Defense and Space Group, Seattle, Washington, D.C. (United States), AD-A259 828/2/GAR, 56 pp. (30 Jun. 1992) Due to demanding requirements imposed on current and future highperformance aerospace structures, advanced materials are being developed for an used in a variety of aircraft/aerospace applications. Production costs for advanced materials are generally higher and the payback will be greater for data leading to, faster decision making or improvement in the product. The evaluation capability of CT overcomes the limitation of current qualitative inspection techniques to provide an objective measure of material or component condition. The results of studies involving CT testing of various advanced materials manufacturing processes and joining methods revealed four specific areas in which there is potential for significant economic benefit from CT. 53712 Georgeson,G.E.; Crews, A.R.: Bossi, R.H. X-ray computed tomography for casting development Boeing Defense and Space Group, Seattle, Washington (United States), AD-A261 786/8/GAR, 52 pp. (Sep. 1992) Computed tomngraphy (CT) has been used to evaluate specific sand casting product examples for technical and economic benefits. The areas which would benefit include internal dimensional measurements (eliminating destructive sectioning), specific region inspections, flaw characterization in critical regions (to allow passing or informed repair of castings), and geometric acquisition for CAD/CAM. 53711 Bossi,R.H.; Crews, A.R.; Georgeson, G.E. X-ray computed tomography for failure analysis Boeing Defense and Space Group, Seattle, Washington (United States), AD-A261 884/I/GAR, 56 pp. (Aug. 1992) Under a preliminary testing task assignment of the Advanced Development of X-ray Computed Tomngraphy Application program, computed tomography (CT) has been studied for its potential as a tool to assist in failure analysis investigations. CT provides three-dimensional spatial distribution of material that can be used to assess internal configurations and material conditions nondestructively. This capability has been used in failure analysis studies to determine the position of internal components and their operation. CT is particularly advantageous on complex systems, composite failure studies, and testing under operational or environmental conditions. CT plays an important role in reducing the time and effort of a failure analysis investigation. 53511 Drake,S.G. Improved real-time x-ray technology widens the horizons of industrial computer tomography British Journal of Non-Destructive Testing, Vol. 35, No. 10, pp. 580- 83 (Oct. 1993) As a result of collaboration between OIS Engineering and the National NDT Centre (NNDTC), Harwell, two new computer tomography systems have been recently developed. The f'wst provides for high definition, microfocal CT down to five microns resolution, whilst the second was used for the in-field inspection of wooden power transmission poles at ground level. 53509 Stinson,M.C.; Holloway, D.A.; Ellingson, W.A. Quantification of volume flaw sizes in ceramics by image processing of 3D x-ray tomographic d a t a sets Ceramic Engineering and Science Proceedings, Vol. 14, No. 7-8, pp. 485- 491 (Jul.-Aug. 1993) This paper introduces a technique to quantify internal flaws in a ceramic body. The approach uses data images obtained from 3D X-ray computed tomography. An approach called guided segmentation uses image processing methods applied to a series of the data images to quantify the flaw volumes. The technique is tested on synthesized data for spheres. The technique is then applied to real images of known size to examine its use. 53507 Quinto,E.T. Computed tomography and rockets Conference on Math Methods in Tomography, Oberwolfach (Germany), 5-11 Jun. 1990. pp. 261-268. Springer-Verlag (1991) We describe our exterior reconstruction algorithm that reconstructs the outer shell of an object using only X-ray tomographic data that passes