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Stress analysis on aluminium alloy 7075 (AlZn6MgCu)
S o v i e t J o u r n a l o f N o n d e s t r u c t i v e T e s t i n g , Vol. 23, No. 9, pp. 633-635 ( M a y 1988) The results of using the KIFM-1 coercive force meter for measurement of uniaxiai mechanical stresses are presented, utilising the correlation relationship with the anisotropy of the coercive force. The operation of a magnetoelastic tester developed on the basis of the KIFM-1 is described. 38410
Prosser, W.H.; Green, R.E. Jr.
Ultrasonic characterization of the nonlinear elastic properties of g r a p h i t e / e p o x y composites U l t r a s o n i c s I n t e r n a t i o n a l 87, C o n f e r e n c e P r o c e e d i n g s , L o n d o n ( U n i t e d K i n g d o m ) , 6-9 Jul. 1987. pp. 172-177. B u t t e r w o r t h a n d Co. ( P u b l i s h e r s ) L t d . , G u i l d f o r d , S u r r e y (1987) The normalized change in the ultrasonic "natural" velocity was measured as a function of stress and temperature in a unidirectional laminate of T300/5208 graphite/epoxy composite. These measurements were made using a pulsed phase locked loop ultrasonic interferometer at 2.25 MHz. The stress dependence of the velocity and the linear (second order) elastic moduli were used to calculate some of the nonlinear (third order) moduli of this material. This research provides the basis for ultrasonic techniques to determine residual stress (strain) in composite materials that develops upon curing due to mismatch of coefficients of thermal expansion. 38335
Rumble, S.J.; Sparrow, J.G.
Review of ultrasonic velocity methods of determining residual stress Aeronautical Research Laboratories, Melbourne (Australia), ADA160-769, v p ( M a y 1985) This paper summarizes the techniques used to determine residual stresses. It notes that whilst velocity methods have not been refined to the stage of practical use, they show considerable promise. The theoretical basis, and the experimental techniques of the ultrasonic methods are reviewed with emphasis on the separation of the competing effects of texture and stress on ultrasonic velocity. 38267
Chambonnet, D.; Gauthier, R.; M'Ghaieth, R.; Pinard, P.
Experimental analysis of residual stresses in semiconductor materials R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 343-352. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) A new method has been developed for stress analysis in semiconductor materials based on a symbiosis of two technics : classical infrared photoelasticity and up-to date digit image processing. The separation of the principal stresses is achieved by means of a microcomputer, the collection and analysis of the photoelastic fringe patterns (isoclinic and isochromatic lines), then the stress calculations are made automatically. Finally, this procedure permits observation of a sixteen pseudocolor imaging of the spreading of residual stresses in the semiconductor slices with a resolution of the order of 10 MPa. 38257
Teodorescu, H.N.; Talmacu, M.; Sofron, E.; Popa, M.
R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s o f the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 361-368. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) One of the most detrimental effects on the accuracy of an X-ray diffraction residual stress analysis, XRDRSA(1), is found in the examination of textured materials. The degree of elastic anisotropy and texture is in general agreement with the extent of the error in the residual stress. The main objective of this work is to determine a direct experimental method for measuring X-ray strain, in steel, independent of texture, similar to using the (310) reflection which utilizes the information displayed in a pole figure. The approach taken in this work was to try and find a texture independent path (TIP) for the (211) CrK(alpha) reflection, and test the procedure with textured steel, in which known stress levels have been introduced by means of a cantilever bar system. The final phase of the project was to demonstrate a simple experimental means to find and apply the value of the strain-free d spacing, do, in the stressed steel. 38227
Eigenmann, B.; Wagner, C.N.J.
Stress analysis on aluminum alloy 7075 (AIZn6MgCu) R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s o f the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 319-326. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) A method for X-ray stress analysis, using lattice strains measured in different directions was applied to specimens of the heat-treatable AI- alloy 7075. The stress free lattice parameter was determined and it was shown that it changes with the state of the heat treatment. The entire stress tensor was evaluated using the value of the stress free lattice parameter. 38226
Konaga, T.; Kohno, H.; Manabe, H.
X-ray diffraction technique for measuring stress in c o a t i n g s R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 191-198. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) It is well known that residual stresses in coatings are introduced from evaporation of solvent and crosslinking under the curing process, and also with temperature and humidity in actual service. From these reasons, in the development of coated products, a relation between cracking in coatings and excessive residual strains or stresses is often a problem. The stress in a coating is ordinarily measured by use of the "bimetal method". The authors have investigated a method using X-ray diffraction on aluminum powder which is dispersed in a coating as a stress marker. The merits of this method are its capability to measure stress directly on products themselves. In this paper, the authors, first, review some fundamental experiments with this method, and then, report the method is applicable to measuring stress in a prime coating on a plastic substrate which is to be sputter coated with a metal.
Specific techniques by optical emission in stress analysis R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 311-318. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) The present paper presents some basic aspects of a new method in experimental stress analysis, with emphasis on the determination of residual stresses relaxation. The method is based on the effect of optical emission under mechanical stress (OEMS), a phenomenon somewhat similar to the acoustic emission. The main topics this paper deals with are : the physical back-ground of the method, the experimental principles, the testing techniques, the experimental results and the conclusions and some proposals for further developments and improvements. The experimental facts prove the utility of OEMS tests in many areas of stress analysis, mainly : stress in the non-linear region, investigation of fracture and residual stress relaxation mechanisms, behaviour of adhesives before and at the fracture limit and mechanical degradation of macromolecular materials. 38230
Rosemeier, R. G.
X-ray diffraction measurement of residual stress(strain): Energy dispersive X-ray residual stress measurement John Hopkins University, Baltimore, Maryland (United States), P h . D . Thesis, 262 pp. (1981) As a result of forming, joining, machining, grinding, shot peening, carburizing, nitriding, and heat treating processes, a solid material is often found to be in a state of internal stress (strain) even though all externally applied stresses have been removed. This internal stress state is commonly termed residual stress. The term, residual stress, is used in this thesis in order to conform to conventional usage, although what is actually measured in all cases is residual strain. Since these residual stresses (stains) can markedly affect the performance of a material, it is important to be able to measure them. In the present thesis x-ray diffraction techniques, the oldest of the nondestructive methods for measurement of residual stress, are thoroughly investigated. This thesis is divided into two sections: (I) X-ray Diffraction Measurement of Residual Stress (Strain) and (II) Energy Dispersive X-ray Residual Stress Analysis. 38228
Gazzara, C.P.
The texture independent path (TIP) method of X-ray residual s t r e s s analysis (XRDRSA) on textured steel
NDT International December 1989
38225
Pintschovius, L.; Macherauch, E.; Scholtes, B.
Determination of residual stresses in autofrettaged steel tubes by neutron and X-ray diffraction R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 159-166. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) The residual stress state of an autofrettaged 30 CrNiMo8 steel tube has been investigated by neutron and X-ray diffraction. The results of X- ray measurements on the face of a ring cut out of the tube agree well with the neutron results obtained on the central part of an unmachined specimen. As expected the tangential stress component at the inner diameter was found to be largest and is compressive. However, the distributions of the tangential and radial residual stress components show large deviations from the expected values. The differences between experiment and theory are probably due to neglecting the Bauschinger effect, the decarburization of the surface layers and the residual stresses produced by an alignment procedure before the autofrettage process. Annealing the tube for I h at 450 deg C has little effect on the residual stress distribution, except for a reduction of the steep gradient of the tangential stress component close to the inner surface.
Allen, A.J.; Bourke, M.; Hutchings, M.T.; Krawitz, A.D.; Windsor, C. G.
38224
Neutron diffraction measurement of internal stress in bulk m a t e r i a l s : m e t a l - m a t r i x composites R e s i d u a l Stresses in S c i e n c e a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 151-158. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) In this paper, some preliminary results are reported of experiments using the neutron diffraction technique to measure residual and load- induced strains in metal-matrix composite (MMC) materials. The technique utilises the ability of the neutron to penetrate into a metal to a depth of several cm., and has been developed at Harwell to give unique information on internal stress fields within weldments, components and model test pieces. Parallel work at other laboratories has made this technique one which is now available in most countries for the investigation of samples of a size which may be taken to a
371
Prosser, W.H.; Green, R.E. Jr.
Ultrasonic characterization of the nonlinear elastic properties of g r a p h i t e / e p o x y composites U l t r a s o n i c s I n t e r n a t i o n a l 87, C o n f e r e n c e P r o c e e d i n g s , L o n d o n ( U n i t e d K i n g d o m ) , 6-9 Jul. 1987. pp. 172-177. B u t t e r w o r t h a n d Co. ( P u b l i s h e r s ) L t d . , G u i l d f o r d , S u r r e y (1987) The normalized change in the ultrasonic "natural" velocity was measured as a function of stress and temperature in a unidirectional laminate of T300/5208 graphite/epoxy composite. These measurements were made using a pulsed phase locked loop ultrasonic interferometer at 2.25 MHz. The stress dependence of the velocity and the linear (second order) elastic moduli were used to calculate some of the nonlinear (third order) moduli of this material. This research provides the basis for ultrasonic techniques to determine residual stress (strain) in composite materials that develops upon curing due to mismatch of coefficients of thermal expansion. 38335
Rumble, S.J.; Sparrow, J.G.
Review of ultrasonic velocity methods of determining residual stress Aeronautical Research Laboratories, Melbourne (Australia), ADA160-769, v p ( M a y 1985) This paper summarizes the techniques used to determine residual stresses. It notes that whilst velocity methods have not been refined to the stage of practical use, they show considerable promise. The theoretical basis, and the experimental techniques of the ultrasonic methods are reviewed with emphasis on the separation of the competing effects of texture and stress on ultrasonic velocity. 38267
Chambonnet, D.; Gauthier, R.; M'Ghaieth, R.; Pinard, P.
Experimental analysis of residual stresses in semiconductor materials R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 343-352. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) A new method has been developed for stress analysis in semiconductor materials based on a symbiosis of two technics : classical infrared photoelasticity and up-to date digit image processing. The separation of the principal stresses is achieved by means of a microcomputer, the collection and analysis of the photoelastic fringe patterns (isoclinic and isochromatic lines), then the stress calculations are made automatically. Finally, this procedure permits observation of a sixteen pseudocolor imaging of the spreading of residual stresses in the semiconductor slices with a resolution of the order of 10 MPa. 38257
Teodorescu, H.N.; Talmacu, M.; Sofron, E.; Popa, M.
R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s o f the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 361-368. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) One of the most detrimental effects on the accuracy of an X-ray diffraction residual stress analysis, XRDRSA(1), is found in the examination of textured materials. The degree of elastic anisotropy and texture is in general agreement with the extent of the error in the residual stress. The main objective of this work is to determine a direct experimental method for measuring X-ray strain, in steel, independent of texture, similar to using the (310) reflection which utilizes the information displayed in a pole figure. The approach taken in this work was to try and find a texture independent path (TIP) for the (211) CrK(alpha) reflection, and test the procedure with textured steel, in which known stress levels have been introduced by means of a cantilever bar system. The final phase of the project was to demonstrate a simple experimental means to find and apply the value of the strain-free d spacing, do, in the stressed steel. 38227
Eigenmann, B.; Wagner, C.N.J.
Stress analysis on aluminum alloy 7075 (AIZn6MgCu) R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s o f the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 319-326. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) A method for X-ray stress analysis, using lattice strains measured in different directions was applied to specimens of the heat-treatable AI- alloy 7075. The stress free lattice parameter was determined and it was shown that it changes with the state of the heat treatment. The entire stress tensor was evaluated using the value of the stress free lattice parameter. 38226
Konaga, T.; Kohno, H.; Manabe, H.
X-ray diffraction technique for measuring stress in c o a t i n g s R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 191-198. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) It is well known that residual stresses in coatings are introduced from evaporation of solvent and crosslinking under the curing process, and also with temperature and humidity in actual service. From these reasons, in the development of coated products, a relation between cracking in coatings and excessive residual strains or stresses is often a problem. The stress in a coating is ordinarily measured by use of the "bimetal method". The authors have investigated a method using X-ray diffraction on aluminum powder which is dispersed in a coating as a stress marker. The merits of this method are its capability to measure stress directly on products themselves. In this paper, the authors, first, review some fundamental experiments with this method, and then, report the method is applicable to measuring stress in a prime coating on a plastic substrate which is to be sputter coated with a metal.
Specific techniques by optical emission in stress analysis R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 311-318. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) The present paper presents some basic aspects of a new method in experimental stress analysis, with emphasis on the determination of residual stresses relaxation. The method is based on the effect of optical emission under mechanical stress (OEMS), a phenomenon somewhat similar to the acoustic emission. The main topics this paper deals with are : the physical back-ground of the method, the experimental principles, the testing techniques, the experimental results and the conclusions and some proposals for further developments and improvements. The experimental facts prove the utility of OEMS tests in many areas of stress analysis, mainly : stress in the non-linear region, investigation of fracture and residual stress relaxation mechanisms, behaviour of adhesives before and at the fracture limit and mechanical degradation of macromolecular materials. 38230
Rosemeier, R. G.
X-ray diffraction measurement of residual stress(strain): Energy dispersive X-ray residual stress measurement John Hopkins University, Baltimore, Maryland (United States), P h . D . Thesis, 262 pp. (1981) As a result of forming, joining, machining, grinding, shot peening, carburizing, nitriding, and heat treating processes, a solid material is often found to be in a state of internal stress (strain) even though all externally applied stresses have been removed. This internal stress state is commonly termed residual stress. The term, residual stress, is used in this thesis in order to conform to conventional usage, although what is actually measured in all cases is residual strain. Since these residual stresses (stains) can markedly affect the performance of a material, it is important to be able to measure them. In the present thesis x-ray diffraction techniques, the oldest of the nondestructive methods for measurement of residual stress, are thoroughly investigated. This thesis is divided into two sections: (I) X-ray Diffraction Measurement of Residual Stress (Strain) and (II) Energy Dispersive X-ray Residual Stress Analysis. 38228
Gazzara, C.P.
The texture independent path (TIP) method of X-ray residual s t r e s s analysis (XRDRSA) on textured steel
NDT International December 1989
38225
Pintschovius, L.; Macherauch, E.; Scholtes, B.
Determination of residual stresses in autofrettaged steel tubes by neutron and X-ray diffraction R e s i d u a l Stresses in Science a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 159-166. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) The residual stress state of an autofrettaged 30 CrNiMo8 steel tube has been investigated by neutron and X-ray diffraction. The results of X- ray measurements on the face of a ring cut out of the tube agree well with the neutron results obtained on the central part of an unmachined specimen. As expected the tangential stress component at the inner diameter was found to be largest and is compressive. However, the distributions of the tangential and radial residual stress components show large deviations from the expected values. The differences between experiment and theory are probably due to neglecting the Bauschinger effect, the decarburization of the surface layers and the residual stresses produced by an alignment procedure before the autofrettage process. Annealing the tube for I h at 450 deg C has little effect on the residual stress distribution, except for a reduction of the steep gradient of the tangential stress component close to the inner surface.
Allen, A.J.; Bourke, M.; Hutchings, M.T.; Krawitz, A.D.; Windsor, C. G.
38224
Neutron diffraction measurement of internal stress in bulk m a t e r i a l s : m e t a l - m a t r i x composites R e s i d u a l Stresses in S c i e n c e a n d T e c h n o l o g y . P r o c e e d i n g s of the I n t e r n a t i o n a l C o n f e r e n c e , G a r m i s c h - P a r t e n k i r c h e n ( F R G ) , Oct. 1986. pp. 151-158. D e u t s c h e G e s e l l s c h a f t fur M e t a l l k u n d e , 1059 pp. (1987) In this paper, some preliminary results are reported of experiments using the neutron diffraction technique to measure residual and load- induced strains in metal-matrix composite (MMC) materials. The technique utilises the ability of the neutron to penetrate into a metal to a depth of several cm., and has been developed at Harwell to give unique information on internal stress fields within weldments, components and model test pieces. Parallel work at other laboratories has made this technique one which is now available in most countries for the investigation of samples of a size which may be taken to a
371