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Characterization of film adhesion by acoustic microscopy
Materials Evaluation, Vol. 47, No. 2, pp. 2 3 3 - 2 4 0 (Feb. 1989) Acousto-uhrasonic (AU) measurements followed by destructive shear tests have been performed using single-lap joint specimens made from steel adherends joined with FM300 film adhesive. Controlled degradation in the bond-line strength was achieved by exposing the bonded specimens to elevated temperatures. The results indicate a good correlation between AU wave-propagation characteristics and the residual shear strength of the bonded joints. The data provide support for an analytic description of wave propagation through the adherend-adhesive system. 4 0 8 0 6 Pilarski. A.; Rose, J.L.; Da-Le, J. T r a n s v e r s e a n d p l a t e w a v e s f o r adhesive bond interface evaluation Proceedings of the 12th World C o n f e r e n c e on Non-Destructive Testing, A m s t e r d a m (Netherlands) 2 3 - 2 8 Apr. 1989. Vol. 1, pp. 836-841. Edited by J. B o o g a a r d and G.M. van Dijk, Elsevier, 1989 Two approaches for the detection of interracial weakness between an adhesive and adherend are proposed here. The first technique employs transverse waves at an angle of incidence chosen from numerically established angular characteristics of the reflection factor in the case of two elastic media connected by different boundary conditions. A comparison of experimental and theoretical results confirms the importance of frequency and angle selection. The second approach is based on plate wave behavior in three layered medium with imperfections on the individual interfaces. A selection of appropriate modes was obtained indirectly by a numerical analysis of the dispersion relations. The different degrees of sensitivity of the individual plate wave modes either In inlerfacial conditions or to changes in glue line thickness and its cohesive propenies was underlined. 4 0 4 2 8 Rokhlin, S.I. C h a r a c t e r i z a t i o n of composite and adhesive cure by ultrasonic waves Nondestructive Characterisation o f Materials 2, Montreal (Canada), 21- 23 Jul, 1986. pp. 105-114. Edited by J.F. Bussiere, J.P. Monchalin, C.O. Ruud, R.E. G r e e n Jr. Plenum Press, 1987 Measurements of the velocity and attenuation of ultrasonic waves during curing of composite materials and structural adhesives is shown to offer important information on the mechanical properties of the material. This paper also describes the temperature dependence of velocity and attenuation in longitudinal waves at different stages of the cure reaction. A simple technique for adhesive cure monitoring is described.
Lethierq, M.; Bahoua, J.C.: Perdrix. M. Nondestructive characterization of thin adhesive bonds
40424
Nondestructive Characterisation of Materials 2, Montreal (Canada), 21- 23 Jul. 1986. pp. 395-402. Edited by J.F. Bussiere, J.P. Monchalin, C.O. R u u d , R.E. Green Jr. Plenum Press, 1987 This study aims to discover if a combination of ultrasonic tests and electrical measurements can characterize cyanoacrylale adhesive bonds in materials like aluminium, steel and ceramics. A large number of such bonds were tested with longitudinal and shear ultrasonic waves as well as electrical measurements. A destructive test gave the shear mechanical resistance of each bond. Experimental results were processed into primary signals in order to derive parameters to characterize the bonds. Results also produced the principle component analysis from an automatic data analysis algorithm. 40296
Pilarski, A.; Rose. J.L.; Dale, J.; Balasabramaniam, K.; Lecuru,
D. An ultrasonic oblique incidence technique for adhesive bond quality evaluation N o n - D e s t r u c t i v e Testing, Proceedings o f the 4th E u r o p e a n Conference, L o n d o n (United K i n g d o m ) , 13-17 Sep. 1987. Vol. 4, pp. 2 2 3 7 - 2 2 4 4 . Edited By J.M. Farley and R . W . Nichols. P e r g a m o n Press, 1988. This technique employs transverse waves with an angle of incidence chosen from numerically established angular characteristics for the reflection factor in the case of different boundary conditions. The interface with imperfections was modeled with bond rigidity of a finite value or with the so-called 'smooth' boundary condition. The second approach proposed here. also utilizing oblique incidence, is based on plate wave behavior in a three layered medium with imperfections on the individual interfaces. A selection of the appropriate modes for the adhesion weakness detection was obtained by a numerical analysis of the dispersion curves. The experimental measurements were carried out on adhesively bonded aluminium specimens.
Madaras, E.I.; Wil!t?ee. W.P.; Smith, B.T.; Heyman, J.H. Detection of bondline delaminations in multilayer structures with Iossy components
Review o f Progress in Quantitative Nondestructive Evaluation. Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 1685-1694. Edited by D . D . T h o m p s o n a n d D.E. Chimenti, Plenum Press. 1988. The development of an automated system for ultrasonic mapping of autohesion and other joining related defects in heat-fused polyethylene gas distribution pipe joints is discussed. Leading into the system description a brief summary of how polyethylene is joined and the types of defects that can occur is presented. Elastic wave interactions with polyethylene and autohesion defects are outlined to define the flaw detectability problem, particularly, as it relates to the requirements for development of an automated system.
Gosse, J.H.; Hause, L.R. Quantitative nondestructive evaluation of adhesive bond strength 40059
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 953-960. Edited by D,D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. It is well known that adhesively bonded systems can exhibit variability in mechanical performance even when the systems under evaluation are fabricated identically and appear to lack major anomalies such as those determined by through-transmission ultrasonics (voids, disbonds, etc.). Obviously. the ability to nondestmctively determine adhesive bond performance is needed if these systems are to be utilized in a load bearing capacity. The nondestructive evaluation of any materials systems is most successful when the physics of the materials in the system are understood in terms of their interaction with each other during both fabrication and under service loading conditions. The anatomy of a bonded system consists of several material subsystems. The work described in this paper involves a single lap shear bonded configuration. The anatomy of the bonded system consists of the metal adherends, the surface treatment, the low viscosity primer, and finally the adhesive itself.
Batra, N.K.; Chaskelis, H.H. Determination of delaminations in adhesively bonded layers under compression 40058
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States). 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 943-952. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988, To determine the presence of delaminations in adhesively bonded layers by ultrasonic methods, the changes which occur in the propagating ultrasonic energy must be uniquely attributable to the delamination effects. Determination of absolute attenuation and its variation in each adberend layer is prerequisite. In addition, the distinction between adhesively bonded interfaces from tho~ just in physical contact must be established. In this paper, a systematic study of the effect of compression on bonded and unbonded areas on ultrasonic attenuation is de~ribed. The results of the simulation experiment are used to interpret digital images of adhesively bonded polyethylene- rubber-steel piston inserts.
Teller, C.M.; Diercks, K J. Nondestructive evaluation of adhesive bonds using leaky Lamb waves
40057
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 935-942. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. The present work focused on adhesive bonds formed between robber and metal adherends. The~ are used in many structures whose primary function is to ~al an internal space from an external corrosive or otherwise harmful environment. A specific concern of the Navy is the seal that also functions as an acoustic window at the radiating end of an underwater sonar transducer. Bond failures here may allow water to enter the transducer housing resulting in catastrophic failure, or may alter the acoustic coupling between the radiating components thereby degrading acoustic performance. The approach pursued in this investigation was the leaky Lamb wave method, an ultrasonic method that relies on excitation of a boundary-sensitive plate (Lamb) wave in the metallic adherend of a bonded rubber/metal laminate. The work reported here demonstrates that the method is also promising for detecting and delineating flaws in rubber-to-metal bond surfaces.
40278
Proceedings o f the IEEE 1987 Ultrasonic S y m p o s i u m , Denver, C o l o r a d o (United States), 14-16 Oct. 1987. Vol. 2, pp. 1047-1052. Edited by B.R. M c A v o y . Institute o f Electrical and Electronics Engineers. The detection of bondline delaminations in multi-layer structures using ultrasonic reflection techniques is a problem in adhesively bonded composite structures such as the Space Shuttle's Solid Rocked Motors (SRM). The SRM is made up of a resonant steel layer backed by layers of adhesive, rubber, liner, and fuel. which are ultrasonically attenuating. The structure's response is modeled as a Iossy ultra~nic transmission line. The model predicts that the acoustic respon~ of the system is sensitive to delaminations at the interior bondlines in a few narrow frequency bands. These predictions are verified by measurements on a fabricated system. Successful imaging of internal delanfinations is sensitive to proper selection of the interrogating frequency. Images of fabricated bondline delaminations are presented based on these studies.
House. L,I. A n automated system for mapping autohesion and other joining related defects in polyethylene heat-fused pipe joints 40115
104
He, F.; Rokhlin, S.I.; Adler, L. Application of SH and Lamb wave EMAT's for evaluation of adhesive .joint in thin plate 40054
R e v i e w o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B. pp. 911-918. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. The applicability of shear horizontal SH wave for the evaluation of adhesive joint in thin plate was studied. The advantages of the SH guided wave is that its displacement and stress are oriented parallel to the adhesive-adherent interface, and therefore, it can be u ~ d to evaluate interface properties. The experimental studies are focused on the relations between acoustic parameters and geometry conditions, the comparison of ultrasonic data and strength data of the joint, and the attenuation in different cases. The experiments were done on lap-shearsamples and long samples. For excitation and reception of SH waves, non-contact electromagnetic tran~ucers were used. An additional investigation was carried out using Lamb waves for the same sample parameters.
MaI, A.K.; Weglein, R.D. Characterization of film adhesion by acoustic microscopy
40053
NDT& E International Volume 25 Number 2 1992
Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jan. 1987. Vol. 7B, pp. 903-910. Edited by D.D. Thompson and D.E. Chimenti, Plenum Press, 1988. Accurate and reliable information on adhesive bond strength between dissimilar solids is an important factor in joint technology. In spite of considerable efforts to obtain a quantitative measure of film adhesion, this parameter remains elusive. While this reference work shows the wide interest in the measurement of adhesion between solid surfaces as well as between films and solids, a reliable measure of bond strength has to date not materialized. At present the acoustic microscope cannot di~ero the interface differences exisling between two mating surfaces that are ~mewhere between welded and smooth compressional contact nor measure the continuous range of film adhesion strength between the welded contact and the disbond conditions. A quantitative technique is con~quenlly desired by which the bond strength at an interface can be characterized and measured simply, rapidly and with cost effectiveness.
Beall, F.C. Monitoring of in-situ curing of various wood.bonding adhesives using acousto-ultrasonic transmission 39877
International Journal Adhesion and Adhesives, Vol. 9, No. 1, pp. 21-25 (Jan. 1989) Hard maple adberends were bonded with six different types of adhesives while monitoring the curing process by acousto-ultrasonic transmission. Adhesives included hot melt, cellulo~ nitrate, polyvinylacetate, epoxy, cyanoacrylate, and resorcinol. The adherends were lapped for a 25 x 25 mm bond area and either shimmed or lightly clamped. Standard acoustic emissions sensors, 175 kHz transmitter and 75 kHz receiver, were used to generate a root mean ~uare (RMS) voltage output which increa~d as the adhesive cured. The transmission increase was quantified using a half-time to cure. The diffusion of solvents from cellulo~ nitrate and cyanoacrylate adhesives appeared to cau~ complex and variable transmission. Hot melt, polyvinylacetate and remrcinol produced curves similar to tho~ previously reported for epoxies. In all ca~s, the presence of shims had a dominant effect on the nature of the transmission curves.
Guyott, C.C.H.; Cawley, P. Ultrasonic spectroscopy for the detection of poor cohesive properties in adhesive joints 39565
Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1678-1687. Pergamon Press, 3173 pp. (1988) The natural frequencies of the longitudinal (through-thickness) modes of an adhesive joint have been predicted using receplance analysis and measured using ultrasonic spectromopy. Excellent agreement has been obtained between the predicted and measured frequencies of joints with a wide range of adhesive thicknes~s and moduli. At low adhesive thicknes~s, the modes tend to occur in pairs, but at higher thicknesses, this pairing no longer occurs. This phenomenon has been explained in terms of the mode shapes of the different modes, and the role of the adhesive layer in determining their frequencies. The results indicate that it should be possible to
Each entry in N D T Abstracts consists of the serial n u m b e r in the National N D T Centre Information Store for identification purposes; the title of the paper, b o o k or report; the n a m e of the author; the n a m e of the source journal or d o c u m e n t and the abstracts. Where necessary, ' a u t h o r ' s names and the title of foreign journals have been transliterated into the Latin alphabet according to British Standard BS 2979 : 1958.
Availability of Publications M o s t papers listed m a y be obtained as loans or copies via local library or direct from Loans Department, British Library D o c u m e n t Supply Centre, Boston Spa, Wetberby, Yorkshire LS23 7BQ. Details of the British Lending L i b r a r y ' s U K and International Services m a y be obtained from The Director, British Library Lending Division. Technical reports are also available from the Loans D e p a r t m e n t of the British Lending Library and in the USA from the N a t i o n a l Technical
NDT& E International Volume 25 Number 2 1992
calculate the thickness and modulus of the adhesive layer from measurements of the resonant frequencies of the joint. This would repm~nt a significant advance in the non-destructive testing of adhesive joints.
Crocker, R.L.; Harrison, R.P. High speed digital ultrasonic inspection techniques for the evaluation of diffusion and adhesive bonds 39563
Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1661-1667. Pergamon Press, 3173 pp. (1988) Techniques are described which enable the quality of diffusion bonds between similar and dissimilar materials to be as~ssed in a real-time inspection procedure using high frequency (50-100 MHz) ultrasound. The signal reflected from the diffusionbonded region is interrogated using high speed electronics, in which a pattern recognition system determines the bond quality, enabling a permanent record to be made. Quality as~ssment in adhesive and solder bonds using a digitally- controlled ultrasonic analysis system is described. A system has been developed which uses an IBM-PC compatible computer to control and record the ultrasonic information and to control a manning acoustic microscope.
Pilarski. A.; Rose, J.L. Ultrasonic oblique incidence for improved sensitivity in interface weakness determination 39026
NDT International, Vol. 21, No. 4, pp. 241-246 (Aug. 1988) An ultrasonic oblique incidence technique is propo~d to help ~lve the problem of interfacial weakness detection between adhesive and adherend in adhesively bonded structures. The technique employs transver~ waves with an angle of incidence chosen from numerically established angular characteristics of the reflection factor for different interface boundary conditions. The interface with imperfections is modelled as a bond having a rigidity of a finite value, covering a range of delamination from 'smooth' lo a 'welded' or perfect bond. Experimental measurements carried out on adhesively bonded aluminium - epoxy resin specimens illustrate quite nicely the increased sensitivity of using transver~ waves for interfacial weakness detection. To improve sensitivity, a signal feature in the frequency domain is also used.
Guyott, C.C.H.; Cawley, P. Evaluation of the cohesive properties of adhesive joints using ultrasonic spectroscopy 39025
NDT International, Vol. 21, No. 4, pp. 233-240 (Aug. 1988) The use of ultrasonic spectroscopy for the nondestructive determination of the cohesive properties of the adhesive layer in a joint has been investigated. It has been shown thai measurements of the through- thickness natural frequencies of the joint obtained using ultrasonic spectroscopy can be used to calculate the modulus and lhickness of the adhesive layer. The results reported here indicate thai the thickness may be determined to an accuracy of 4-- 10% and the modulus to an accuracy of +20%. However, it is anticipated thai more sophisticated processing will enable the results to be improved considerably. No other lest is available whom results enable both these parameters to be determined at once, and it is anticipated that the test will be very valuable in ensuring that the process quality control during the joint manufacture has been satisfactory.
I n f o r m a t i o n Service, US D e p a r t m e n t of C o m m e r c e , Springfield, Virginia 22151, USA. British and foreign standards can be obtained from Sales Department, British Standards Institution, 101 Pentonville Road, L o n d o n N1 9 N D ; and British and foreign patents from the Patents Office Sales Branch, Block C, Station Square House, St M a r y Cray, Orpington, Kent BR5 3RD.
Information-retrieval Service All entries are indexed in a computerized retrieval system, located at Harwell, which allows rapid searching of information relevant to any particular inspection problem. This service is available to b o t h U K and overseas organizations t h r o u g h the National N D T Centre's Qualtis Subscription Scheme - further details are available from Phil Lawrence on Abingdon (0235) 433391. © 1992 United K i n g d o m Atomic Energy Authority
105
Lethierq, M.; Bahoua, J.C.: Perdrix. M. Nondestructive characterization of thin adhesive bonds
40424
Nondestructive Characterisation of Materials 2, Montreal (Canada), 21- 23 Jul. 1986. pp. 395-402. Edited by J.F. Bussiere, J.P. Monchalin, C.O. R u u d , R.E. Green Jr. Plenum Press, 1987 This study aims to discover if a combination of ultrasonic tests and electrical measurements can characterize cyanoacrylale adhesive bonds in materials like aluminium, steel and ceramics. A large number of such bonds were tested with longitudinal and shear ultrasonic waves as well as electrical measurements. A destructive test gave the shear mechanical resistance of each bond. Experimental results were processed into primary signals in order to derive parameters to characterize the bonds. Results also produced the principle component analysis from an automatic data analysis algorithm. 40296
Pilarski, A.; Rose. J.L.; Dale, J.; Balasabramaniam, K.; Lecuru,
D. An ultrasonic oblique incidence technique for adhesive bond quality evaluation N o n - D e s t r u c t i v e Testing, Proceedings o f the 4th E u r o p e a n Conference, L o n d o n (United K i n g d o m ) , 13-17 Sep. 1987. Vol. 4, pp. 2 2 3 7 - 2 2 4 4 . Edited By J.M. Farley and R . W . Nichols. P e r g a m o n Press, 1988. This technique employs transverse waves with an angle of incidence chosen from numerically established angular characteristics for the reflection factor in the case of different boundary conditions. The interface with imperfections was modeled with bond rigidity of a finite value or with the so-called 'smooth' boundary condition. The second approach proposed here. also utilizing oblique incidence, is based on plate wave behavior in a three layered medium with imperfections on the individual interfaces. A selection of the appropriate modes for the adhesion weakness detection was obtained by a numerical analysis of the dispersion curves. The experimental measurements were carried out on adhesively bonded aluminium specimens.
Madaras, E.I.; Wil!t?ee. W.P.; Smith, B.T.; Heyman, J.H. Detection of bondline delaminations in multilayer structures with Iossy components
Review o f Progress in Quantitative Nondestructive Evaluation. Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 1685-1694. Edited by D . D . T h o m p s o n a n d D.E. Chimenti, Plenum Press. 1988. The development of an automated system for ultrasonic mapping of autohesion and other joining related defects in heat-fused polyethylene gas distribution pipe joints is discussed. Leading into the system description a brief summary of how polyethylene is joined and the types of defects that can occur is presented. Elastic wave interactions with polyethylene and autohesion defects are outlined to define the flaw detectability problem, particularly, as it relates to the requirements for development of an automated system.
Gosse, J.H.; Hause, L.R. Quantitative nondestructive evaluation of adhesive bond strength 40059
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 953-960. Edited by D,D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. It is well known that adhesively bonded systems can exhibit variability in mechanical performance even when the systems under evaluation are fabricated identically and appear to lack major anomalies such as those determined by through-transmission ultrasonics (voids, disbonds, etc.). Obviously. the ability to nondestmctively determine adhesive bond performance is needed if these systems are to be utilized in a load bearing capacity. The nondestructive evaluation of any materials systems is most successful when the physics of the materials in the system are understood in terms of their interaction with each other during both fabrication and under service loading conditions. The anatomy of a bonded system consists of several material subsystems. The work described in this paper involves a single lap shear bonded configuration. The anatomy of the bonded system consists of the metal adherends, the surface treatment, the low viscosity primer, and finally the adhesive itself.
Batra, N.K.; Chaskelis, H.H. Determination of delaminations in adhesively bonded layers under compression 40058
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States). 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 943-952. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988, To determine the presence of delaminations in adhesively bonded layers by ultrasonic methods, the changes which occur in the propagating ultrasonic energy must be uniquely attributable to the delamination effects. Determination of absolute attenuation and its variation in each adberend layer is prerequisite. In addition, the distinction between adhesively bonded interfaces from tho~ just in physical contact must be established. In this paper, a systematic study of the effect of compression on bonded and unbonded areas on ultrasonic attenuation is de~ribed. The results of the simulation experiment are used to interpret digital images of adhesively bonded polyethylene- rubber-steel piston inserts.
Teller, C.M.; Diercks, K J. Nondestructive evaluation of adhesive bonds using leaky Lamb waves
40057
Review o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B, pp. 935-942. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. The present work focused on adhesive bonds formed between robber and metal adherends. The~ are used in many structures whose primary function is to ~al an internal space from an external corrosive or otherwise harmful environment. A specific concern of the Navy is the seal that also functions as an acoustic window at the radiating end of an underwater sonar transducer. Bond failures here may allow water to enter the transducer housing resulting in catastrophic failure, or may alter the acoustic coupling between the radiating components thereby degrading acoustic performance. The approach pursued in this investigation was the leaky Lamb wave method, an ultrasonic method that relies on excitation of a boundary-sensitive plate (Lamb) wave in the metallic adherend of a bonded rubber/metal laminate. The work reported here demonstrates that the method is also promising for detecting and delineating flaws in rubber-to-metal bond surfaces.
40278
Proceedings o f the IEEE 1987 Ultrasonic S y m p o s i u m , Denver, C o l o r a d o (United States), 14-16 Oct. 1987. Vol. 2, pp. 1047-1052. Edited by B.R. M c A v o y . Institute o f Electrical and Electronics Engineers. The detection of bondline delaminations in multi-layer structures using ultrasonic reflection techniques is a problem in adhesively bonded composite structures such as the Space Shuttle's Solid Rocked Motors (SRM). The SRM is made up of a resonant steel layer backed by layers of adhesive, rubber, liner, and fuel. which are ultrasonically attenuating. The structure's response is modeled as a Iossy ultra~nic transmission line. The model predicts that the acoustic respon~ of the system is sensitive to delaminations at the interior bondlines in a few narrow frequency bands. These predictions are verified by measurements on a fabricated system. Successful imaging of internal delanfinations is sensitive to proper selection of the interrogating frequency. Images of fabricated bondline delaminations are presented based on these studies.
House. L,I. A n automated system for mapping autohesion and other joining related defects in polyethylene heat-fused pipe joints 40115
104
He, F.; Rokhlin, S.I.; Adler, L. Application of SH and Lamb wave EMAT's for evaluation of adhesive .joint in thin plate 40054
R e v i e w o f Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 2 2 - 2 6 Jun. 1987. Vol. 7B. pp. 911-918. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. The applicability of shear horizontal SH wave for the evaluation of adhesive joint in thin plate was studied. The advantages of the SH guided wave is that its displacement and stress are oriented parallel to the adhesive-adherent interface, and therefore, it can be u ~ d to evaluate interface properties. The experimental studies are focused on the relations between acoustic parameters and geometry conditions, the comparison of ultrasonic data and strength data of the joint, and the attenuation in different cases. The experiments were done on lap-shearsamples and long samples. For excitation and reception of SH waves, non-contact electromagnetic tran~ucers were used. An additional investigation was carried out using Lamb waves for the same sample parameters.
MaI, A.K.; Weglein, R.D. Characterization of film adhesion by acoustic microscopy
40053
NDT& E International Volume 25 Number 2 1992
Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jan. 1987. Vol. 7B, pp. 903-910. Edited by D.D. Thompson and D.E. Chimenti, Plenum Press, 1988. Accurate and reliable information on adhesive bond strength between dissimilar solids is an important factor in joint technology. In spite of considerable efforts to obtain a quantitative measure of film adhesion, this parameter remains elusive. While this reference work shows the wide interest in the measurement of adhesion between solid surfaces as well as between films and solids, a reliable measure of bond strength has to date not materialized. At present the acoustic microscope cannot di~ero the interface differences exisling between two mating surfaces that are ~mewhere between welded and smooth compressional contact nor measure the continuous range of film adhesion strength between the welded contact and the disbond conditions. A quantitative technique is con~quenlly desired by which the bond strength at an interface can be characterized and measured simply, rapidly and with cost effectiveness.
Beall, F.C. Monitoring of in-situ curing of various wood.bonding adhesives using acousto-ultrasonic transmission 39877
International Journal Adhesion and Adhesives, Vol. 9, No. 1, pp. 21-25 (Jan. 1989) Hard maple adberends were bonded with six different types of adhesives while monitoring the curing process by acousto-ultrasonic transmission. Adhesives included hot melt, cellulo~ nitrate, polyvinylacetate, epoxy, cyanoacrylate, and resorcinol. The adherends were lapped for a 25 x 25 mm bond area and either shimmed or lightly clamped. Standard acoustic emissions sensors, 175 kHz transmitter and 75 kHz receiver, were used to generate a root mean ~uare (RMS) voltage output which increa~d as the adhesive cured. The transmission increase was quantified using a half-time to cure. The diffusion of solvents from cellulo~ nitrate and cyanoacrylate adhesives appeared to cau~ complex and variable transmission. Hot melt, polyvinylacetate and remrcinol produced curves similar to tho~ previously reported for epoxies. In all ca~s, the presence of shims had a dominant effect on the nature of the transmission curves.
Guyott, C.C.H.; Cawley, P. Ultrasonic spectroscopy for the detection of poor cohesive properties in adhesive joints 39565
Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1678-1687. Pergamon Press, 3173 pp. (1988) The natural frequencies of the longitudinal (through-thickness) modes of an adhesive joint have been predicted using receplance analysis and measured using ultrasonic spectromopy. Excellent agreement has been obtained between the predicted and measured frequencies of joints with a wide range of adhesive thicknes~s and moduli. At low adhesive thicknes~s, the modes tend to occur in pairs, but at higher thicknesses, this pairing no longer occurs. This phenomenon has been explained in terms of the mode shapes of the different modes, and the role of the adhesive layer in determining their frequencies. The results indicate that it should be possible to
Each entry in N D T Abstracts consists of the serial n u m b e r in the National N D T Centre Information Store for identification purposes; the title of the paper, b o o k or report; the n a m e of the author; the n a m e of the source journal or d o c u m e n t and the abstracts. Where necessary, ' a u t h o r ' s names and the title of foreign journals have been transliterated into the Latin alphabet according to British Standard BS 2979 : 1958.
Availability of Publications M o s t papers listed m a y be obtained as loans or copies via local library or direct from Loans Department, British Library D o c u m e n t Supply Centre, Boston Spa, Wetberby, Yorkshire LS23 7BQ. Details of the British Lending L i b r a r y ' s U K and International Services m a y be obtained from The Director, British Library Lending Division. Technical reports are also available from the Loans D e p a r t m e n t of the British Lending Library and in the USA from the N a t i o n a l Technical
NDT& E International Volume 25 Number 2 1992
calculate the thickness and modulus of the adhesive layer from measurements of the resonant frequencies of the joint. This would repm~nt a significant advance in the non-destructive testing of adhesive joints.
Crocker, R.L.; Harrison, R.P. High speed digital ultrasonic inspection techniques for the evaluation of diffusion and adhesive bonds 39563
Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1661-1667. Pergamon Press, 3173 pp. (1988) Techniques are described which enable the quality of diffusion bonds between similar and dissimilar materials to be as~ssed in a real-time inspection procedure using high frequency (50-100 MHz) ultrasound. The signal reflected from the diffusionbonded region is interrogated using high speed electronics, in which a pattern recognition system determines the bond quality, enabling a permanent record to be made. Quality as~ssment in adhesive and solder bonds using a digitally- controlled ultrasonic analysis system is described. A system has been developed which uses an IBM-PC compatible computer to control and record the ultrasonic information and to control a manning acoustic microscope.
Pilarski. A.; Rose, J.L. Ultrasonic oblique incidence for improved sensitivity in interface weakness determination 39026
NDT International, Vol. 21, No. 4, pp. 241-246 (Aug. 1988) An ultrasonic oblique incidence technique is propo~d to help ~lve the problem of interfacial weakness detection between adhesive and adherend in adhesively bonded structures. The technique employs transver~ waves with an angle of incidence chosen from numerically established angular characteristics of the reflection factor for different interface boundary conditions. The interface with imperfections is modelled as a bond having a rigidity of a finite value, covering a range of delamination from 'smooth' lo a 'welded' or perfect bond. Experimental measurements carried out on adhesively bonded aluminium - epoxy resin specimens illustrate quite nicely the increased sensitivity of using transver~ waves for interfacial weakness detection. To improve sensitivity, a signal feature in the frequency domain is also used.
Guyott, C.C.H.; Cawley, P. Evaluation of the cohesive properties of adhesive joints using ultrasonic spectroscopy 39025
NDT International, Vol. 21, No. 4, pp. 233-240 (Aug. 1988) The use of ultrasonic spectroscopy for the nondestructive determination of the cohesive properties of the adhesive layer in a joint has been investigated. It has been shown thai measurements of the through- thickness natural frequencies of the joint obtained using ultrasonic spectroscopy can be used to calculate the modulus and lhickness of the adhesive layer. The results reported here indicate thai the thickness may be determined to an accuracy of 4-- 10% and the modulus to an accuracy of +20%. However, it is anticipated thai more sophisticated processing will enable the results to be improved considerably. No other lest is available whom results enable both these parameters to be determined at once, and it is anticipated that the test will be very valuable in ensuring that the process quality control during the joint manufacture has been satisfactory.
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