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Acousto-ultrasonics for adhesive bond evaluation
-ND
T a b s tra c ts - = =
NDT Abstracts is a current awareness service compiled by the National NDT Centre, Harwell Laboratory, Didcot, Oxon, O X l l 0RA, UK. The entries are drawn from over 500 British and International publications. Each issue concentrates on one or two subject areas. The subjects covered in previous issues from February 1991 onwards are: Artificial intelligence in N D T - 25(1); G a m m a t o m o g r a p h y - 24(3); M a g n e t o - a c o u s t i c e m i s s i o n and the Barkhausen effect - 24(1); Radiographic inspection o f welds - 24(4); U l t r a s o n i c and acoustic testing of concrete - 24(5); Vibration testing - 24(2); W i r e rope inspection - 24(6)
Acoustic techniques for adhesive bond evaluation
49786
Moursund, B.; Baltzersen, 0.; Melve, B. Effect of defects on acoustic emission from GRP tubular adhesive joints
4 9 4 6 4 Papadakis, E.P.: Chapman, G.B. Q u a n t i t a t i v e n o n d e s t r u c t i v e e v a l u a t i o n of a d h e s i v e lap joints in sheet
4th World Meeting on Acoustic Emission. (AEWG-35) Ist International Conference on Acoustic Emission in Manufacturing. Boston, Massachusetts (United States), 16-19 Sep. 1991. pp. 419-424. Edited by S.J. Vahaviolos. ASNT (1991) Pipes of filament wound glassfibre reinforced epoxy have been investigated with acoustic emission and ultrasound. Two short pipes were connected with an adhesive overlap joint bonded. The pipes were then subjected to internal pressure. By varying the defect type and the size it was possible to distinguish between non-critical and critical defects.
molding compound by adaptation of a commercial bond tester
49695 de Belleval, J.F.; Benelmostafa, U.; Mercier, N.; Molinero, I. O p t i m i s a t i o n of u l t r a s o u n d adhesive bond testing methods using n u m e r i c a l modeling Ultrasonics International 91, Le Touquet (France), 1-4 Jul. 1991. pp. 527-530. Bunerworth Heinemann ( 1991 ) This paper pre~nts a method which permits the optimum conditions to test adhesive bonds by ultrasound to be evaluated using a numerical model. The model calculates the propagation of ultrasonic waves in a multilayer medium for various boundary conditions (perfect and imperfect) which simulate a good or bad adhesive bond. It is used to establish the dispersion curves of Lamb waves for the multilayer medium. The parameters for which there is a difference between good and bad conditions permit the bond to be evaluated. A practical application of the method and experimental results is predated.
Tung, W.; Courouhle-h'sid, B. Lamb waves in m u l t i l a y e r e d m e d i a
49684
Ultrasonics International 91, Le Touquet (France). I-4 Jul. 1991. pp. 579-582. Butterworth Heinemann ( 1991 ) In order to improve the mechanic's and acoustic's properties, the multilayered materials has recently become a subject of intensive study. The different materials are assembled by a glue. To optimize the composite performance, it is needful to get a whole adhesion between the different materials. The detection of adhesion's flaw can be executed by the non destructive control, utilizing the propagation of Lamb waves in multilayered media. The dispersive properties of Lamb waves complicate the propagation's studies. In this letter, a study and plotting of dispersion curves of different modes of guided waves in multilayered media is described. 49667 Quaftouh, M.; Xu, W.J.; Ourak. M.; Nongaillard, B. E v a l u a t i o n of adhesion by means of h i g h - f r e q u e n c y u l t r a s o u n d (In French: English A b s t r a c t ) Journal de Physique 4. Colloque C1, Vol. 2, pp. 835-838 (Apr. 1992) Numerous studies have already been performed for estimating the adhesion between two materials using ultrasound. The results obtained, mainly with Lamb waves, don't lead to a quantitative evaluation of adhesion. We investigated the use of high frequency, 50 to 500 MHz, bulk (longitudinal and shear) ultrasonic waves for evaluating the adhesion form the reflection or transmission coefficient at an interface. 49646 Fahr, A.; YousseJ~ Y.; Roy, C.: Tanary. S. A c o u s t o - u l t r a s o n i c s for a d h e s i v e b o n d e v a l u a t i o n National Research Council of Canada, Ottawa, Ontario (Canada), N9212289/4/GAR, 17 pp. (Sep. 1990) 1'he structural u ~ of adhesively bonded bonded joints, particularly in in aerospace applications, requires the use of nondestructive evaluation (NDE) techniques for the characterization and qualification of bond integrity. In this paper, experimental results from Acousto Ultrasonic (AU) measurements and pattern recognition analysis followed by destructive shear tests on single-lap joint specimens made from either metallic or carbon fiber composite adherends and commercial adhesives with different types of bond line defects are presented. The results indicate that it is possible to separate samples with contaminated surfaced and degraded adhesives from wellbonded specimens with excellent recognition rates. Also, good correlations were found between the stress wave propagation characteristics and the shear strength of the bonded joint.
NDT& E International Volume 25 Number 2 1992
NDE - The Vehicle to the Future, Orlando, Florida (United States), 30 Mar. - 3 Apr. 1992. pp. 53-55. ASNT (1992) A method has been devi,,~,d to obtain quantitative NDE measurements from a commercial adhesive bond tester designed for GO/NO-GO qualitative sorting. The bond tester operates by exciting the material under inspection with a ~ries of acoustic pul~s from the transmitting tran~ucer, and detecting the resulting wave train with the receiving transducer. Adhesive bond defects are detected by comparing the wave train of the pul~s received from the specimen to the wave train of pul~s received, during previous calibration, from a reference specimen bond of known integrity. The method for the choice of proper referencing specimens as standards u ~ s statistical analysis. With the reference specimens and the quantitative output, the instrument can be u~d to make measurements which correlate with adhesive bond strength. With the reference specimens and the built-in alarm mode oftbe instroment, measurements can be made to define a probability of detection (POD) for disbonds versus disbond size. With this POD in hand, a Specification for an adhesive lap joint in terms of an acceptable percentage of bonded area was defined.
Hosten, B. Ultrasonic transmission of adhesively bonded structures for large FD
49398
Ultrasonics International 91, Le Touquet (France), I-4 Jul. 1991. pp. 443-446. Butterworth Heinemann (I 991 ). This paper pre~nts the application of the Tbomson-Haskell method with bulk heterogeneous waves to the prediction of waveforms transmitted by adhesively bonded structures. This numerical method is still stable for large values of the product of the frequency by the thickness of the medium (FD) and permits a simple simulation of transmission through interface with varying boundaryconditions. The~ conditions are not always weak conditions like in the pre~nce of defects, but also ~ m e surface preparations like ~ndblasting, enhance the transmi.~sion when the adherent surfaces are roughened. Experimental verifications are given for steel/epoxy/steel stratified media. 49397 Billson, D.R.; Hutchins, D.A. U l t r a s o n i c testing of adhesively bonded layers using s h e a r w a v e s Ultrasonics International 91, Le Touquet (France), 1-4 Jul. 1991. pp. 447-450. Butterworth Heinemann (1991). The frequency respon~ of shear waves at normal incidence has been investigated both theoretically and experimentally as a possible technique for testing the bond strength of adhesive joints. The pul~- echo shear spectrum at normal incidence of a perfect joint was modelled on a computer, and was shown to compare well with experimental results. This model was then altered to try to repre~nt a poorly bonded joint. Noting the difference between the spectra, preliminary experiments were undertaken to try to verify this experimentally. 49396 Pialucha, T.P.; Cawley, P. T h e reflection of u l t r a s o u n d from embedded i n t e r f a c e l a y e r s in a d h e s i v e joints Ultrasonics International 91, 12 Touquet (France), I-4 Jul. 1991. pp. 451-454. Butterworth Heinemann (1991). The use of ultrasonic reflection coefficient measurements for the detection of weak adhesive-adherend interlayers in adhesive joints has been investigated. It has been shown that at practical inspection frequencies of up to 100 MHz, it will only be possible to detect ~vere degradation of a 1 mu m thick interlayer. If the interlayer thickness is increa~d, detection of moderate degradation is possible. 49395 Ouaftouh, M.; Ourak, M.; Xu, W.I.; Nongaillard, B.; Lefehvre, J.E.; Rouvaen. J M. Non d e s t r u c t i v e e v a l u a t i o n of bonded assemblies using u l t r a s o n i c waves Ultrasonics International 91, 12 Touquet (France), 1-4 Jul. 1991. pp. 455-458. Butterworth Heinemann (I 99 I). A study of the potentialities of ultra~nic non destructive evaluation of adhesion defects in bonded joints, using low frequency guided waves or high frequency longitudinal and shear bulk waves is reported. A model for the transmission of
95
T a b s tra c ts - = =
NDT Abstracts is a current awareness service compiled by the National NDT Centre, Harwell Laboratory, Didcot, Oxon, O X l l 0RA, UK. The entries are drawn from over 500 British and International publications. Each issue concentrates on one or two subject areas. The subjects covered in previous issues from February 1991 onwards are: Artificial intelligence in N D T - 25(1); G a m m a t o m o g r a p h y - 24(3); M a g n e t o - a c o u s t i c e m i s s i o n and the Barkhausen effect - 24(1); Radiographic inspection o f welds - 24(4); U l t r a s o n i c and acoustic testing of concrete - 24(5); Vibration testing - 24(2); W i r e rope inspection - 24(6)
Acoustic techniques for adhesive bond evaluation
49786
Moursund, B.; Baltzersen, 0.; Melve, B. Effect of defects on acoustic emission from GRP tubular adhesive joints
4 9 4 6 4 Papadakis, E.P.: Chapman, G.B. Q u a n t i t a t i v e n o n d e s t r u c t i v e e v a l u a t i o n of a d h e s i v e lap joints in sheet
4th World Meeting on Acoustic Emission. (AEWG-35) Ist International Conference on Acoustic Emission in Manufacturing. Boston, Massachusetts (United States), 16-19 Sep. 1991. pp. 419-424. Edited by S.J. Vahaviolos. ASNT (1991) Pipes of filament wound glassfibre reinforced epoxy have been investigated with acoustic emission and ultrasound. Two short pipes were connected with an adhesive overlap joint bonded. The pipes were then subjected to internal pressure. By varying the defect type and the size it was possible to distinguish between non-critical and critical defects.
molding compound by adaptation of a commercial bond tester
49695 de Belleval, J.F.; Benelmostafa, U.; Mercier, N.; Molinero, I. O p t i m i s a t i o n of u l t r a s o u n d adhesive bond testing methods using n u m e r i c a l modeling Ultrasonics International 91, Le Touquet (France), 1-4 Jul. 1991. pp. 527-530. Bunerworth Heinemann ( 1991 ) This paper pre~nts a method which permits the optimum conditions to test adhesive bonds by ultrasound to be evaluated using a numerical model. The model calculates the propagation of ultrasonic waves in a multilayer medium for various boundary conditions (perfect and imperfect) which simulate a good or bad adhesive bond. It is used to establish the dispersion curves of Lamb waves for the multilayer medium. The parameters for which there is a difference between good and bad conditions permit the bond to be evaluated. A practical application of the method and experimental results is predated.
Tung, W.; Courouhle-h'sid, B. Lamb waves in m u l t i l a y e r e d m e d i a
49684
Ultrasonics International 91, Le Touquet (France). I-4 Jul. 1991. pp. 579-582. Butterworth Heinemann ( 1991 ) In order to improve the mechanic's and acoustic's properties, the multilayered materials has recently become a subject of intensive study. The different materials are assembled by a glue. To optimize the composite performance, it is needful to get a whole adhesion between the different materials. The detection of adhesion's flaw can be executed by the non destructive control, utilizing the propagation of Lamb waves in multilayered media. The dispersive properties of Lamb waves complicate the propagation's studies. In this letter, a study and plotting of dispersion curves of different modes of guided waves in multilayered media is described. 49667 Quaftouh, M.; Xu, W.J.; Ourak. M.; Nongaillard, B. E v a l u a t i o n of adhesion by means of h i g h - f r e q u e n c y u l t r a s o u n d (In French: English A b s t r a c t ) Journal de Physique 4. Colloque C1, Vol. 2, pp. 835-838 (Apr. 1992) Numerous studies have already been performed for estimating the adhesion between two materials using ultrasound. The results obtained, mainly with Lamb waves, don't lead to a quantitative evaluation of adhesion. We investigated the use of high frequency, 50 to 500 MHz, bulk (longitudinal and shear) ultrasonic waves for evaluating the adhesion form the reflection or transmission coefficient at an interface. 49646 Fahr, A.; YousseJ~ Y.; Roy, C.: Tanary. S. A c o u s t o - u l t r a s o n i c s for a d h e s i v e b o n d e v a l u a t i o n National Research Council of Canada, Ottawa, Ontario (Canada), N9212289/4/GAR, 17 pp. (Sep. 1990) 1'he structural u ~ of adhesively bonded bonded joints, particularly in in aerospace applications, requires the use of nondestructive evaluation (NDE) techniques for the characterization and qualification of bond integrity. In this paper, experimental results from Acousto Ultrasonic (AU) measurements and pattern recognition analysis followed by destructive shear tests on single-lap joint specimens made from either metallic or carbon fiber composite adherends and commercial adhesives with different types of bond line defects are presented. The results indicate that it is possible to separate samples with contaminated surfaced and degraded adhesives from wellbonded specimens with excellent recognition rates. Also, good correlations were found between the stress wave propagation characteristics and the shear strength of the bonded joint.
NDT& E International Volume 25 Number 2 1992
NDE - The Vehicle to the Future, Orlando, Florida (United States), 30 Mar. - 3 Apr. 1992. pp. 53-55. ASNT (1992) A method has been devi,,~,d to obtain quantitative NDE measurements from a commercial adhesive bond tester designed for GO/NO-GO qualitative sorting. The bond tester operates by exciting the material under inspection with a ~ries of acoustic pul~s from the transmitting tran~ucer, and detecting the resulting wave train with the receiving transducer. Adhesive bond defects are detected by comparing the wave train of the pul~s received from the specimen to the wave train of pul~s received, during previous calibration, from a reference specimen bond of known integrity. The method for the choice of proper referencing specimens as standards u ~ s statistical analysis. With the reference specimens and the quantitative output, the instrument can be u~d to make measurements which correlate with adhesive bond strength. With the reference specimens and the built-in alarm mode oftbe instroment, measurements can be made to define a probability of detection (POD) for disbonds versus disbond size. With this POD in hand, a Specification for an adhesive lap joint in terms of an acceptable percentage of bonded area was defined.
Hosten, B. Ultrasonic transmission of adhesively bonded structures for large FD
49398
Ultrasonics International 91, Le Touquet (France), I-4 Jul. 1991. pp. 443-446. Butterworth Heinemann (I 991 ). This paper pre~nts the application of the Tbomson-Haskell method with bulk heterogeneous waves to the prediction of waveforms transmitted by adhesively bonded structures. This numerical method is still stable for large values of the product of the frequency by the thickness of the medium (FD) and permits a simple simulation of transmission through interface with varying boundaryconditions. The~ conditions are not always weak conditions like in the pre~nce of defects, but also ~ m e surface preparations like ~ndblasting, enhance the transmi.~sion when the adherent surfaces are roughened. Experimental verifications are given for steel/epoxy/steel stratified media. 49397 Billson, D.R.; Hutchins, D.A. U l t r a s o n i c testing of adhesively bonded layers using s h e a r w a v e s Ultrasonics International 91, Le Touquet (France), 1-4 Jul. 1991. pp. 447-450. Butterworth Heinemann (1991). The frequency respon~ of shear waves at normal incidence has been investigated both theoretically and experimentally as a possible technique for testing the bond strength of adhesive joints. The pul~- echo shear spectrum at normal incidence of a perfect joint was modelled on a computer, and was shown to compare well with experimental results. This model was then altered to try to repre~nt a poorly bonded joint. Noting the difference between the spectra, preliminary experiments were undertaken to try to verify this experimentally. 49396 Pialucha, T.P.; Cawley, P. T h e reflection of u l t r a s o u n d from embedded i n t e r f a c e l a y e r s in a d h e s i v e joints Ultrasonics International 91, 12 Touquet (France), I-4 Jul. 1991. pp. 451-454. Butterworth Heinemann (1991). The use of ultrasonic reflection coefficient measurements for the detection of weak adhesive-adherend interlayers in adhesive joints has been investigated. It has been shown that at practical inspection frequencies of up to 100 MHz, it will only be possible to detect ~vere degradation of a 1 mu m thick interlayer. If the interlayer thickness is increa~d, detection of moderate degradation is possible. 49395 Ouaftouh, M.; Ourak, M.; Xu, W.I.; Nongaillard, B.; Lefehvre, J.E.; Rouvaen. J M. Non d e s t r u c t i v e e v a l u a t i o n of bonded assemblies using u l t r a s o n i c waves Ultrasonics International 91, 12 Touquet (France), 1-4 Jul. 1991. pp. 455-458. Butterworth Heinemann (I 99 I). A study of the potentialities of ultra~nic non destructive evaluation of adhesion defects in bonded joints, using low frequency guided waves or high frequency longitudinal and shear bulk waves is reported. A model for the transmission of
95