| In Situ Process Monitoring Using Laser-Based Ultrasonics |
OCT 94 |
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| Authors:
A. D. McKie; R. C. Addison Jr.; T. L. Liao
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 | In both the aerospace and automotive industries, polymer-based composite materials are increasingly being used to replace metallic structures. However, the economical use of these fiber reinforced materials is critically dependent on the development of robust and efficient manufacturing processes. To reduce the cost of fabricating complexly contoured polymer composite structures, manufacturers are actively developing low-cost alternatives to hand layup/ autoclave curing and other labour and capital-intensive processes. Two methods that ... |
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| In Situ Monitoring of Molding Processes Using Laser-Based Ultrasound |
94 |
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| Authors:
R. C. Addison Jr.; A. D. McKie; T.-l. Liao; H.-s. Ryang
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| Manufacturers of polymer composite materials are seeking more economical methods for fabricating structures with complex contours. Two methods that are being actively pursued are resin transfer molding (RTM) and compression molding of sheet molding compound (SMC). Each of these processes can be improved and made more economical by in situ monitoring. Laser-based ultrasound (LBU) is well suited for this monitoring application since it can be used with heated molds having ... |
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| Rapid Inspection of Composites Using Laser-Based Ultrasound |
93 |
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| Authors:
A. D. McKie; Robert C. Addison Jr.
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| Current techniques for automated inspection of airframe structures can only be used to examine limited areas which have large radii of curvature. Manual inspection techniques are used in areas with small radii. Laser-based ultrasound (LBU) offers the potential to rapidly inspect large-area composite structures having contoured geometries, without restriction to large radii of curvature. To realize the full high speed scanning potential of a same side laser-in/laser-out inspection system, it ... |
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| Quantitative Theory for Laser Ultrasonic Waves in a Thin Plate |
29 OCT 90 |
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| Authors:
J. B. Spicer; A. D. McKie; J. W. Wagner
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| Numerical inversion of the Hankel-Laplace transform has been performed for the case of ultrasonic displacements in an infinite, homogeneous, isotropic plate which is excited thermoelastically by a laser pulse. Values for the elastic moduli and the plate thickness may be extracted when the calculated displacements are compared directly to those obtained experimentally. Previous authors have demonstrated methods for determining the elastic modulus in thick plates; this letter shows that using ... |
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| laser generation of narrow-band and directed ultrasound |
NOV 89 |
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| Authors:
A. D. McKie; J. W. Wagner; J. B. Spicer; C. M. Penney
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| in this paper a technique is described which allows narrow-band, 'toneburst' ultrasonic signals to be directed by laser generation using a spatial array of laser sources. experimental investigations were performed using a laser irradiated lenticular array in order to study the resulting far field ultrasonic displacements. the investigations used a laser source of fixed temporal pulse characteristics and an array of fixed geometry. ultrasonic detection was performed with both a ... |
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