- Email: [email protected]
Theory of acoustoelasticity and acoustoplasticity
37341
Pao, Y-H.
Theory of acoustoelasticity and acoustoplasticity Solid M e c h a n i c s R e s e a r c h for 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 , P r o c e e d i n g s o f the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 257-274. M a r t i n u s Nijhoff P u b l i s h e r s (1987) The theory of acoustoclasticity and several recently developed theories of acoustoplasticity are reviewed in this article. For a body with plastic defomlation, the acoustoelastic birefringence is affected by the initial stress and the texture, and the latter is related to plastic strains and inherent anisotropy of the body. The birefringence formula may be applied to measure residual stresses by ultrasonic techniques. 37340
Sayers, C.M.
37015
Ultrasonic determination of t e x t u r e a n d r e s i d u a l stress in polycrystalline metals Solid M e c h a n i c s R e s e a r c h for 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 , P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d S t a t e s ) , 18-20 Sep. 1985. pp. 319-336. M a r t i n u s N i j h o f f P u b l i s h e r s (1987) In a polycrystalline aggregate the elastic constants in the specimen reference frame vary from grain to grain due to the random orientation of the grains. Polycrystalline metals are therefore elastically inhomogeneous, and the elastic constant mismatch at the grain boundaries leads to scattering of the ultrasonic wave. In the long wavelength limit, however, the metal can be modelled as an elastic continuum with elastic constants determined by the elastic constants of the grains and the crystallite orientation distribution function (CODF). This function gives the probability of a crystallite having a given orientation with respect to the specimen frame, and gives a quantitative description of the texture, or crystallographic alignment, of the material. In a strongly textured metal the yield stress varies as a function of direction and this can lead to non-uniform flow in deep drawing for example. As a result there is a need for a non- destructive measurement of texture in process control, and there is considerable interest in the use of ultrasonics for this purpose. Information on the CODF can be obtained from ultrasonic velocity measurements. 37339
Fukuoka, H.
Ultrasonic measurement of residual stress Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 275-300. M a r t i n u s Nijhoff P u b l i s h e r s (1987) The main point of this paper is a practical application of acoustoelastic measurement of residual stress in industry. 37338
Clark, A.V.; Moulder, J.C.; Mignogna, R.B.; DelSanto, P.P.
A comparison of several ultrasonic techniques for absolute stress determination in the presence of texture Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 345-360. M a r t i n u s Nijhoff P u b l i s h e r s (1987) Most ultrasonic stress measurement techniques measure some combination of stresses, such as the sum or difference of principal stresses, relative to some (possibly unknown) stress state. In order to apply fracture mechanics methods to assessment of flawed structures, stresses must be determined absolutely. Ultrasonic stress measurement methods rely on the acoustoelastic effect: the stress-induced change in phase velocity. Unfortunately, texture also has a comparable effect. This has limited most applications to measurement of applied (as opposed to residual) stress. 37282
Namkung, M.; Utrata, D.; Heyman, J.S.; Allison, S.G.
Low-field magnetoacoustic residual stress measurement in steel Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 301-318. M a r t i n u s N i j h o f f P u b l i s h e r s (1987) Much of the recent development of the magnetoacoustic technique has been devoted to refine the technique described in this paper as a reliable and practical tool for measuring bulk residual stress in steel components. For this, the effects of structural and metallurgical properties on the magnetoacoustic interaction have been studied for various types of steel samples. Also, progress is being made to obtain quantitative residual stress measurements in railroad wheels. This paper reviews the physical basis and the experimental results of the magnetoacoustic stress measurements in steels. 37280
Electric Power Research Institute
Investigation of advanced evaluation techniques
acoustic
and
optical
nondestructive
E l e c t r i c P o w e r R e s e a r c h I n s t i t u t e , Palo A l t o , C a l i f o r n i a ( U n i t e d States), E P R I - N P - 4 8 9 7 , 108 pp. (Oct. 1986) This project was initiated in 1980 to explore advanced acoustic and optical
374
techniques for nondestructive evaluation of nuclear components. The initial task was to evaluate optical sandwich holography as a means to characterize components before and after service use. The fringe patterns would then be compared to determine if any changes had occured during service. This work was completed successfully. The second task was to determine how the ultrasonic tomography research, carried out under RP504-1, could be improved upon so that its potential for residual stress measurement could be fulfilled. The third and major task was to develop acoustical holography to the point of commercialization. Although EPRI (Electric Power Research Institute) had given considerable support to the development of acoustical holography, little attention had been paid to the engineering of a versatile, portable system. A commercial system, the SDL-1000, has been developed and is now available to potential users. The first production unit has been delivered to the EPRI NDE Center where it is being evaluated.
Goebbels, K.
Non-Destructive evaluation of ceramic components for engines C e r a m i c M a t e r i a l s a n d C o m p o n e n t s for E n g i n e s , P r o c e e d i n g s of the 2nd I n t e r n a t i o n a l S y m p o s i u m , L u b e c k - T r a v e m u n d e ( F R G ) 14-17 A p r . 1986. pp. 779-787. E d i t e d by W. B u n k a n d H. H a u s n e r , V e r l a g D e u t s c h e K e r a m i s c h e G e s e l l s c h a f t ( F R G ) , 1205 pp. (1986) Surface defects in ceramics are more critical than internal defects and cracklike defects are much more severe then volumetric flaws such as inclusions. Therefore, NDE methods not only have to detect and to locate the defects, they also have to characterize them in terms of location, type, size and orientation. Microstructural features which need to be characterized by NDE include inhomogeneity and anisotropy; residual stresses can reduce the materials ability to withstand the design load and therefore require quantitative determination. NDE methods considered in this paper for surface inspection include visual inspection, dye penetrants, dye-enhanced radiography and ultrasonic testing with surface waves. In the future acoustic microscopy as well as photoacoustic microscopy will provide the highest sensitivity and resolution for surface inspection problems. Finally, from the point of view of mass production, vibration analysis will provide an attractive quality control method prior to more sophisticated NDE techniques. 36985
Ono, K.
Magnetomechanical acoustic emission - a review U n i v e r s i t y of California, Los A n g e l e s , C a l i f o r n i a ( U n i t e d States), A D - A171-848, 13 pp. (Sep. 1986) This article reviews magnetomechanical acoustic emission (MAE) that can be used in developing nondestructive testing techniques for residual stress measurements and microstructural characterization. Effects of metallurgical and magnetic parameters on MAE are considered drawing from basic studies on nickel and iron as well as from applied research on rail and wheel steels. Some of the observed features of MAE can be explained in terms of the domain theory. Practical applications require additional developmental efforts, but potential for useful residual stress analysis is well demonstrated. 36981
Filinov, V. V.; Sokolik, A.I.; Shaternikov, V.E.
Effect of surface plastic deformation of steel components on the parameters of the Barkhansen effect Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 22, No. 6, pp. 391-394 (Feb. 1987) Investigations were conducted into the effect of the surface plastic deformation of specimens of 30 KhGSA and 30 KhGSN2A steel with a martensitic structure on the actual values of the parameters of the Barkhausen effect. It is shown that the intensity and number of surges of the emf of Barkhausen noise carry different types of information on the physical processes taking place in metals accompanying surface plastic deformation. The results of inspection of the magnitude of residual stresses formed during this deformation are presented. 36901
Pyatykhin, L.I.; Talalaev, N.N.; Chinilina, N. V.
Application of holography for determining residual stresses in coatings I n d u s t r i a l L a b o r a t o r y , Vol. 52, No. 7, pp. 673-674 (Jan. 1987) One of the promising ways of extending the life of paint and varnish coatings comprises investigating and reducing the residual stress level in them. In a previously described method, the residual stresses were evaluated by upsetting the balanced state of stress with the aid of drilling a hole in the material. A shortcoming of this method is impaired accuracy on account of the vibrations accompanying the drilling and the distorting effect of local heating in the region of the holes. In addition, because of possible damage to the substrate, this method is inapplicable for the determination of residual stresses in coatings of real products. The present article explains a method of holographic investigation of residual stresses in paint and varnish coatings which is free of the above shortcomings. 36814
Heyman, J.S.; Namkung, M.
Residual stress measurements in carbon steel A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h and Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 61-74. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986). External dc magnetic field-induced changes in natural velocity of Rayleigh surface waves have been measured in steel specimens under various stress conditions. The low field slopes of curves representing the fractional changes of natural velocity have been proved to provide correct stress information in steels with different metallurgical properties. The slopes of curves under uniaxial
NDT International December 1989
Pao, Y-H.
Theory of acoustoelasticity and acoustoplasticity Solid M e c h a n i c s R e s e a r c h for 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 , P r o c e e d i n g s o f the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 257-274. M a r t i n u s Nijhoff P u b l i s h e r s (1987) The theory of acoustoclasticity and several recently developed theories of acoustoplasticity are reviewed in this article. For a body with plastic defomlation, the acoustoelastic birefringence is affected by the initial stress and the texture, and the latter is related to plastic strains and inherent anisotropy of the body. The birefringence formula may be applied to measure residual stresses by ultrasonic techniques. 37340
Sayers, C.M.
37015
Ultrasonic determination of t e x t u r e a n d r e s i d u a l stress in polycrystalline metals Solid M e c h a n i c s R e s e a r c h for 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 , P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d S t a t e s ) , 18-20 Sep. 1985. pp. 319-336. M a r t i n u s N i j h o f f P u b l i s h e r s (1987) In a polycrystalline aggregate the elastic constants in the specimen reference frame vary from grain to grain due to the random orientation of the grains. Polycrystalline metals are therefore elastically inhomogeneous, and the elastic constant mismatch at the grain boundaries leads to scattering of the ultrasonic wave. In the long wavelength limit, however, the metal can be modelled as an elastic continuum with elastic constants determined by the elastic constants of the grains and the crystallite orientation distribution function (CODF). This function gives the probability of a crystallite having a given orientation with respect to the specimen frame, and gives a quantitative description of the texture, or crystallographic alignment, of the material. In a strongly textured metal the yield stress varies as a function of direction and this can lead to non-uniform flow in deep drawing for example. As a result there is a need for a non- destructive measurement of texture in process control, and there is considerable interest in the use of ultrasonics for this purpose. Information on the CODF can be obtained from ultrasonic velocity measurements. 37339
Fukuoka, H.
Ultrasonic measurement of residual stress Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 275-300. M a r t i n u s Nijhoff P u b l i s h e r s (1987) The main point of this paper is a practical application of acoustoelastic measurement of residual stress in industry. 37338
Clark, A.V.; Moulder, J.C.; Mignogna, R.B.; DelSanto, P.P.
A comparison of several ultrasonic techniques for absolute stress determination in the presence of texture Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 345-360. M a r t i n u s Nijhoff P u b l i s h e r s (1987) Most ultrasonic stress measurement techniques measure some combination of stresses, such as the sum or difference of principal stresses, relative to some (possibly unknown) stress state. In order to apply fracture mechanics methods to assessment of flawed structures, stresses must be determined absolutely. Ultrasonic stress measurement methods rely on the acoustoelastic effect: the stress-induced change in phase velocity. Unfortunately, texture also has a comparable effect. This has limited most applications to measurement of applied (as opposed to residual) stress. 37282
Namkung, M.; Utrata, D.; Heyman, J.S.; Allison, S.G.
Low-field magnetoacoustic residual stress measurement in steel Solid M e c h a n i c s R e s e a r c h for 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 tion, P r o c e e d i n g s of the O N R S y m p o s i u m o n Solid M e c h a n i c s R e s e a r c h for Q N D E , N o r t h w e s t e r n U n i v e r s i t y , E v a n s t o n , Illinois ( U n i t e d States), 18-20 Sep. 1985. pp. 301-318. M a r t i n u s N i j h o f f P u b l i s h e r s (1987) Much of the recent development of the magnetoacoustic technique has been devoted to refine the technique described in this paper as a reliable and practical tool for measuring bulk residual stress in steel components. For this, the effects of structural and metallurgical properties on the magnetoacoustic interaction have been studied for various types of steel samples. Also, progress is being made to obtain quantitative residual stress measurements in railroad wheels. This paper reviews the physical basis and the experimental results of the magnetoacoustic stress measurements in steels. 37280
Electric Power Research Institute
Investigation of advanced evaluation techniques
acoustic
and
optical
nondestructive
E l e c t r i c P o w e r R e s e a r c h I n s t i t u t e , Palo A l t o , C a l i f o r n i a ( U n i t e d States), E P R I - N P - 4 8 9 7 , 108 pp. (Oct. 1986) This project was initiated in 1980 to explore advanced acoustic and optical
374
techniques for nondestructive evaluation of nuclear components. The initial task was to evaluate optical sandwich holography as a means to characterize components before and after service use. The fringe patterns would then be compared to determine if any changes had occured during service. This work was completed successfully. The second task was to determine how the ultrasonic tomography research, carried out under RP504-1, could be improved upon so that its potential for residual stress measurement could be fulfilled. The third and major task was to develop acoustical holography to the point of commercialization. Although EPRI (Electric Power Research Institute) had given considerable support to the development of acoustical holography, little attention had been paid to the engineering of a versatile, portable system. A commercial system, the SDL-1000, has been developed and is now available to potential users. The first production unit has been delivered to the EPRI NDE Center where it is being evaluated.
Goebbels, K.
Non-Destructive evaluation of ceramic components for engines C e r a m i c M a t e r i a l s a n d C o m p o n e n t s for E n g i n e s , P r o c e e d i n g s of the 2nd I n t e r n a t i o n a l S y m p o s i u m , L u b e c k - T r a v e m u n d e ( F R G ) 14-17 A p r . 1986. pp. 779-787. E d i t e d by W. B u n k a n d H. H a u s n e r , V e r l a g D e u t s c h e K e r a m i s c h e G e s e l l s c h a f t ( F R G ) , 1205 pp. (1986) Surface defects in ceramics are more critical than internal defects and cracklike defects are much more severe then volumetric flaws such as inclusions. Therefore, NDE methods not only have to detect and to locate the defects, they also have to characterize them in terms of location, type, size and orientation. Microstructural features which need to be characterized by NDE include inhomogeneity and anisotropy; residual stresses can reduce the materials ability to withstand the design load and therefore require quantitative determination. NDE methods considered in this paper for surface inspection include visual inspection, dye penetrants, dye-enhanced radiography and ultrasonic testing with surface waves. In the future acoustic microscopy as well as photoacoustic microscopy will provide the highest sensitivity and resolution for surface inspection problems. Finally, from the point of view of mass production, vibration analysis will provide an attractive quality control method prior to more sophisticated NDE techniques. 36985
Ono, K.
Magnetomechanical acoustic emission - a review U n i v e r s i t y of California, Los A n g e l e s , C a l i f o r n i a ( U n i t e d States), A D - A171-848, 13 pp. (Sep. 1986) This article reviews magnetomechanical acoustic emission (MAE) that can be used in developing nondestructive testing techniques for residual stress measurements and microstructural characterization. Effects of metallurgical and magnetic parameters on MAE are considered drawing from basic studies on nickel and iron as well as from applied research on rail and wheel steels. Some of the observed features of MAE can be explained in terms of the domain theory. Practical applications require additional developmental efforts, but potential for useful residual stress analysis is well demonstrated. 36981
Filinov, V. V.; Sokolik, A.I.; Shaternikov, V.E.
Effect of surface plastic deformation of steel components on the parameters of the Barkhansen effect Soviet J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 22, No. 6, pp. 391-394 (Feb. 1987) Investigations were conducted into the effect of the surface plastic deformation of specimens of 30 KhGSA and 30 KhGSN2A steel with a martensitic structure on the actual values of the parameters of the Barkhausen effect. It is shown that the intensity and number of surges of the emf of Barkhausen noise carry different types of information on the physical processes taking place in metals accompanying surface plastic deformation. The results of inspection of the magnitude of residual stresses formed during this deformation are presented. 36901
Pyatykhin, L.I.; Talalaev, N.N.; Chinilina, N. V.
Application of holography for determining residual stresses in coatings I n d u s t r i a l L a b o r a t o r y , Vol. 52, No. 7, pp. 673-674 (Jan. 1987) One of the promising ways of extending the life of paint and varnish coatings comprises investigating and reducing the residual stress level in them. In a previously described method, the residual stresses were evaluated by upsetting the balanced state of stress with the aid of drilling a hole in the material. A shortcoming of this method is impaired accuracy on account of the vibrations accompanying the drilling and the distorting effect of local heating in the region of the holes. In addition, because of possible damage to the substrate, this method is inapplicable for the determination of residual stresses in coatings of real products. The present article explains a method of holographic investigation of residual stresses in paint and varnish coatings which is free of the above shortcomings. 36814
Heyman, J.S.; Namkung, M.
Residual stress measurements in carbon steel A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h and Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 61-74. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986). External dc magnetic field-induced changes in natural velocity of Rayleigh surface waves have been measured in steel specimens under various stress conditions. The low field slopes of curves representing the fractional changes of natural velocity have been proved to provide correct stress information in steels with different metallurgical properties. The slopes of curves under uniaxial
NDT International December 1989