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Pulsed photothermal nondestructive testing application to carbon expoxy laminates
ND T abstracts 46029 Deom, A.A.; Boscher, D.; Balageas, D.L. Pulsed photothermal nondestructive testing application to carbon expoxy laminates Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9A, pp. 525- 531. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) Pulsed back emission photothermal radiometry seems attractive because it is a simple method, where elasticity is uncoupled. So the possibility of quantitatively characterizing delaminations is offered, as the model describing the phenomenon is simple. Results recently obtained at the Office National d'Etudes et de Rechercbes Aerospatiales (ONERA) are presented here to demonstrate that the method is well suited to the detection, in-depth localization and characterization of delamiuations in carbon-epoxy composites.
45779 Zalameda, J~N.; Winfree, W.P. Thermal diffusivity measurements on composite porosity samples Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9B, pp. 1541- 1548. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) In this work a thermal diffusivity technique is investigated for the characterization of porosity in graphite composite parts. The use of a phase lag technique is used to make quantitative measurements of diffusivity in composite porosity samples. The design and calibration of a single point, noncontacting, noncryogenic thermal diffusivity measurement system is described. In addition, the fabrication of 16 ply composite with 1, 2, 4, and 8 percent manufactured porosity is presented along with measurement approach used for maximum sensitivity for defect inspection. Results of the through-ply diffusivity changes due to the varying porosity levels is shown. The relationship between amount of porosity and change in diffusivity is analyzed using an electrical analog for modelling heat flow in the composite. 45776 Connolly, M.; Copley, D. T h e r m o g r a p h i c inspection of composite material Materials Evaluation, Vol. 48, No. 12, pp. 1461-1463 (Dec. 1990) Some of the limitations of infrared thermography can be overcome using examples described in this paper. The nondestructive technique is used to inspect coated materials (carbon-to-carbon composites) and can detect disbonds between coating and substrate. Photothermal flash heating provides an external heat input. Results presented show hew images can be optimized to produce maximum contrast. Numerical analysis shows that quantitative information on the size and depth of this dishend can be obtained from thermographic images.
Inglehart, Ld. Thermal wave characterization of ceramics
45492
Proceedings of the 6th International Topical Meeting on Photoacoustic and Photothermal Phenomena II, Baltimore, Maryland (United States). 31 Jul.-3 Aug. 1989. Vol. 62, pp. 40-43 Edited by J.C. Murphy, J.W. Maclachlan-Spicer, L.C. Aamondt and B.S.H. Royce. Springer-Verlag (1990). Aspects of ceramics are considered and related to thermal wave imaging. Studies presented include measurements on fiber reinforced
composites, composites with creep damage, and ceramics with controlled particle size and porosity.
Maclachlan Spicer, J.W.; Kerns, W~D.;Aamodt, L.C.; Murphy, J.C. 45490
Time-resolved infrared radiometry for characterization of structured materials Proceedings of the 6th International Topical Meeting on Photoacoustic and Photothermal Phenomena II, Baltimore, Maryland (United States). 31 Jul.-3 Aug. 1989. Vol. 62, pp. 55-58 Edited by J.C. Murphy, J.W. Maclachlan-Spicer, L.C. Aamondt and B.S.H. Royce. Springer-Verlag (1990). Time resolved radiometry is demonstrated both theoretically and experimentally as a parallel, noncontacting method for quantitative imaging of laterally and vertically heterogeneous systems such as composites and coatings systems.
104
NDT&E
International
Volume
26 Number
2 1993
44496 Tretout, H.; Marin, J-V.; De Mol, R. Application of infrared thermography for nondestructive testing of composite materials. (In French) Impact of Emerging NDE-NDI Methods on Aircraft Design, Manufacture and Maintenance, Brussels (Belgium), 1-6 Oct. 1989. pp. 18-1-18-8. AGARD Conference Proceedings No. 462 (1990). ISBN 92 835 05468. 44036 Henneke, E.G. Vibrothermography applied to polymer matrix composites Manual on Experimental Methods for Mechanical Testing of Composites. Edited by R.L. Pendleton and M.E. Tuttle. pp. 129-137. Elsevier Applied Science, 169pp. (1990) ISBN 1 85166 3754. The vibrothermography technique has been applied to polymer-matrix and metal-malrix composites. As this technique is most sensitive, however, to delaminations or delamination-type defects in polymer matrix composites, this chapter will emphasize the applications and selected results that have been obtained for this material type. 44030 Heath, D.M.; Winfree, W.P. Thermal diffusivity in carbon-carbon composites Proceedings of the 15th Annual Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (USA), 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 1613-1619. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1989). ISBN 0-306-43209-9. In this work, a non-contacting measurement technique for measuring thermal diffusivity which utilizes a Nd-YAG laser as a thermal wave source and an IR camera detector is described. Thermal diffusivity is exwacted from the phase delay between the thermal wave source and a spatially offset detection region. Diffusivity measurements taken in a linear pattern over the surface are presented to illustrate the effect of local variations in the fiber direction due to fiber weave in the composite lay-up. In addition, results are given for diffusivity measurements of a series of samples with a range of porosity levels. A strong correlation of diffusivity in the through ply direction with the bulk density, and tberefore with the level of porosity of the composite was shown. 44029 Winfree, W.P.; Welch, C.S.; James, P.H.; Cramer, E. Thermographic detection of delaminations in laminated structures Proceedings of the 15th Annual Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (USA), 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 1657-1662. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1989). ISBN 0-306-43209-9. This paper presents a technique for enhancing the contrast due to a delamination, as well as more clearly delineating the region of the delamination. The technique uses a two-dimensional filter convolved with the thermal image. The filter is designed to approximate operating on the temperature images with a Laplacian operator. Measurements were performed on samples with fabricated defects, and a comparison is presented between the resulting temperature images and the filtered images. 44025 Bakis, C.E.; Reifsnider, K.L. Adiabatic thermoelastic measurements Manual on Experimental Methods for Mechanical Testing of Composites. Edited by R.L. Pendleton and M.E. Tuttle. pp. 139-145. Elsevier Applied Science, 169pp. (1990) ISBN 1 85166 3754 This paper considers adiabatic thermoelastic measurements in composite materials using a device called SPATE (Stress Pattern Analysis by Thermal Emission). This technique is used with homogeneous and heterogeneous materials to evaluate stress and strain fields with contact. The theory of isotropic and anisotropic adiabatic thermoelasticity is developed, and the effects of heterogeneity, lamination and stacking sequence are all considered.
Potet, P.; Lesbre, F.; Bathias, C. Quantitative characterization of impact damage in composite materials a comparison between computerized vibrothermography and X-ray tomography
43747
Nondestructive Testing and Evaluation for Manufacturing and Construction. Edited by H.L.M. dos R¢is. pp. 95-105. Hemisphere Publishing Corporation, (1990). ISBN 0-89116-926-1 A new technique, vibrothermography was developed and proposed for application to composites. It utilizes high frequency low-amplitude mechanical vibrations to induce localized heating in a material. The
45779 Zalameda, J~N.; Winfree, W.P. Thermal diffusivity measurements on composite porosity samples Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9B, pp. 1541- 1548. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) In this work a thermal diffusivity technique is investigated for the characterization of porosity in graphite composite parts. The use of a phase lag technique is used to make quantitative measurements of diffusivity in composite porosity samples. The design and calibration of a single point, noncontacting, noncryogenic thermal diffusivity measurement system is described. In addition, the fabrication of 16 ply composite with 1, 2, 4, and 8 percent manufactured porosity is presented along with measurement approach used for maximum sensitivity for defect inspection. Results of the through-ply diffusivity changes due to the varying porosity levels is shown. The relationship between amount of porosity and change in diffusivity is analyzed using an electrical analog for modelling heat flow in the composite. 45776 Connolly, M.; Copley, D. T h e r m o g r a p h i c inspection of composite material Materials Evaluation, Vol. 48, No. 12, pp. 1461-1463 (Dec. 1990) Some of the limitations of infrared thermography can be overcome using examples described in this paper. The nondestructive technique is used to inspect coated materials (carbon-to-carbon composites) and can detect disbonds between coating and substrate. Photothermal flash heating provides an external heat input. Results presented show hew images can be optimized to produce maximum contrast. Numerical analysis shows that quantitative information on the size and depth of this dishend can be obtained from thermographic images.
Inglehart, Ld. Thermal wave characterization of ceramics
45492
Proceedings of the 6th International Topical Meeting on Photoacoustic and Photothermal Phenomena II, Baltimore, Maryland (United States). 31 Jul.-3 Aug. 1989. Vol. 62, pp. 40-43 Edited by J.C. Murphy, J.W. Maclachlan-Spicer, L.C. Aamondt and B.S.H. Royce. Springer-Verlag (1990). Aspects of ceramics are considered and related to thermal wave imaging. Studies presented include measurements on fiber reinforced
composites, composites with creep damage, and ceramics with controlled particle size and porosity.
Maclachlan Spicer, J.W.; Kerns, W~D.;Aamodt, L.C.; Murphy, J.C. 45490
Time-resolved infrared radiometry for characterization of structured materials Proceedings of the 6th International Topical Meeting on Photoacoustic and Photothermal Phenomena II, Baltimore, Maryland (United States). 31 Jul.-3 Aug. 1989. Vol. 62, pp. 55-58 Edited by J.C. Murphy, J.W. Maclachlan-Spicer, L.C. Aamondt and B.S.H. Royce. Springer-Verlag (1990). Time resolved radiometry is demonstrated both theoretically and experimentally as a parallel, noncontacting method for quantitative imaging of laterally and vertically heterogeneous systems such as composites and coatings systems.
104
NDT&E
International
Volume
26 Number
2 1993
44496 Tretout, H.; Marin, J-V.; De Mol, R. Application of infrared thermography for nondestructive testing of composite materials. (In French) Impact of Emerging NDE-NDI Methods on Aircraft Design, Manufacture and Maintenance, Brussels (Belgium), 1-6 Oct. 1989. pp. 18-1-18-8. AGARD Conference Proceedings No. 462 (1990). ISBN 92 835 05468. 44036 Henneke, E.G. Vibrothermography applied to polymer matrix composites Manual on Experimental Methods for Mechanical Testing of Composites. Edited by R.L. Pendleton and M.E. Tuttle. pp. 129-137. Elsevier Applied Science, 169pp. (1990) ISBN 1 85166 3754. The vibrothermography technique has been applied to polymer-matrix and metal-malrix composites. As this technique is most sensitive, however, to delaminations or delamination-type defects in polymer matrix composites, this chapter will emphasize the applications and selected results that have been obtained for this material type. 44030 Heath, D.M.; Winfree, W.P. Thermal diffusivity in carbon-carbon composites Proceedings of the 15th Annual Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (USA), 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 1613-1619. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1989). ISBN 0-306-43209-9. In this work, a non-contacting measurement technique for measuring thermal diffusivity which utilizes a Nd-YAG laser as a thermal wave source and an IR camera detector is described. Thermal diffusivity is exwacted from the phase delay between the thermal wave source and a spatially offset detection region. Diffusivity measurements taken in a linear pattern over the surface are presented to illustrate the effect of local variations in the fiber direction due to fiber weave in the composite lay-up. In addition, results are given for diffusivity measurements of a series of samples with a range of porosity levels. A strong correlation of diffusivity in the through ply direction with the bulk density, and tberefore with the level of porosity of the composite was shown. 44029 Winfree, W.P.; Welch, C.S.; James, P.H.; Cramer, E. Thermographic detection of delaminations in laminated structures Proceedings of the 15th Annual Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (USA), 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 1657-1662. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1989). ISBN 0-306-43209-9. This paper presents a technique for enhancing the contrast due to a delamination, as well as more clearly delineating the region of the delamination. The technique uses a two-dimensional filter convolved with the thermal image. The filter is designed to approximate operating on the temperature images with a Laplacian operator. Measurements were performed on samples with fabricated defects, and a comparison is presented between the resulting temperature images and the filtered images. 44025 Bakis, C.E.; Reifsnider, K.L. Adiabatic thermoelastic measurements Manual on Experimental Methods for Mechanical Testing of Composites. Edited by R.L. Pendleton and M.E. Tuttle. pp. 139-145. Elsevier Applied Science, 169pp. (1990) ISBN 1 85166 3754 This paper considers adiabatic thermoelastic measurements in composite materials using a device called SPATE (Stress Pattern Analysis by Thermal Emission). This technique is used with homogeneous and heterogeneous materials to evaluate stress and strain fields with contact. The theory of isotropic and anisotropic adiabatic thermoelasticity is developed, and the effects of heterogeneity, lamination and stacking sequence are all considered.
Potet, P.; Lesbre, F.; Bathias, C. Quantitative characterization of impact damage in composite materials a comparison between computerized vibrothermography and X-ray tomography
43747
Nondestructive Testing and Evaluation for Manufacturing and Construction. Edited by H.L.M. dos R¢is. pp. 95-105. Hemisphere Publishing Corporation, (1990). ISBN 0-89116-926-1 A new technique, vibrothermography was developed and proposed for application to composites. It utilizes high frequency low-amplitude mechanical vibrations to induce localized heating in a material. The