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46884 Determination of the elastic constants of anisotropic materials using laser-generated ultrasonic signals
ND T Abstracts partial set of elastic constants C, C. C. (C + 2C), (C + 2C) and (C + 2C), and it is these constants which can therefore be most accurately recovered from longitudinal wavespeed data. A number of illustrative numerical examples are presented which demonstrates the lack of sensitivity to certain constants and illustrate the recovery of elastic constants from simulated longitudinal mode data. These show that there is good convergence for the partial set of elastic constants, whereas the remaining elastic constants are much less accurately recovered.
Wu, D.; Takahashi, S. Determination of the elastic constants of photoelastic material at freezing temperature by the method of caustics (In Japanese: English Abstracts)
47610
Journal o f JSNDi, Vol. 40, No. 8, pp. 530-535 (Aug. 1991) The photoelastic method of stress analysis is a powerful tool applied to a large number of engineering problems. It is very important to obtain the mechanical properties of photoelastic material experimentally, in this paper, an experimental technique to determine the modulus of transverse elasticity of photoelastic material at the freezing temperature is presented by usingthe method of caustics in combination with the photoelastic stress freezing method. It is possible to determine the modulus of transverse elasticity G with the simple experimental apparatus, and the result of Poisson's ratio obtained in this experiment is in good agreement with the result of the traditional method.
Wang, W.: Rokhlin, S.I. Nondestructive determination of elastic constants of ceramic composites
47243
Conference on Nondestructive Evaluation of Modern Ceramics, Columbus, Ohio (United States), 9-12 Jul. 1990. pp. 78-83 ASNT, (1991) The concept and technique of using ultrasonic antiresonance to detenmine elastic constants of thin-plate anisotropic media have been introduced by the authors. The technique is based on measuring zerotransmission angles and from these angles reconstructing the elastic constants, in this work, this technique is utilized to measure the elastic constants of ceramic composites of two kinds: composites with second phase oriented normal to the plane of the plate and thosewith second phases oriented in the plane of the plate. The materials are an anodized honeycomb AIO and fiber-reinforced SiC/AI composite.
Papadakis, E.P.; Patton, T.; Tsai, Y.-M.; Thompson, D.O.; Thompson, R.B. The elastic moduli of a thick composite as measured by ultrasonic bulk wave pulse velocity 46902
Journal of the Acoustical Society of America, Vol. 89, No. 6, pp. 2753- 2757 (Jun. 1991) One thick filament-wound composite in the form of a large thick-walled cylinder with locally orthorhombic symmetry has been measured by ultrasonic velocity to calculate its elastic moduli. The basic assumption was that small sections of the composite could be treated as a homogeneous body analogous to a crystal for ultrasonic propagation. The experimental work and the results as best expressing homogeneous body theory are presented. Because of the high anisotropy with the normal to the layers (the three-direction) much different from the axial and hoop directions, it was necessary to calculate slowness surfaces with approximate values of c and c in order to find the directions of the Poynting vectors to use in making actual measurements on c and c.
Castagnede, B,; Kim, K.Y.; Sachse, W.; Thompson, M,O. Determination of the elastic constants of anisotropic materials using laser-generated ultrasonic signals
46884
Journal o f Applied Physics, Vol. 70, No. I, pp. 150-157 (1 Jul. 1991) This paper presents the solution of the materials characterization problem in which the elastic constants of an anisotropic material are determined from ultrasonic wavespeed measurements made in nonprincipal directions of a specimen. The ultrasonic waves were generated via the point-source/point-receiver technique using a pulsed laser as a source and a miniature, point-like transducer as a receiver. In each waveform the arrivals of the quasi-longitudinal and the two quasi-shear bulk modes were measured and the elastic constants of the material were then recovered using an optimization algorithm. Experimental results are presented for a transversely isotropic, unidirectional fiberglass/polyester and a single crystal specimen of silicon. It was found that the nonlinear fit between the measured and the recovered longitudinal slowness values is excellent. Some discrepancies are observed in the data for the two shear modes. These are shown to be related to the complexity of the detected signals.
50
N D T & E International 1994 Volume 27, Number 1
46876 Blessing, G.V. The pulsed ultrasonic velocity m e t h o d for d e t e r m i n i n g material dynamic elastic moduli Dynamic Elastic Modulus Measurements in Materials, ASTM STP 1045. Edited by A. Wolfenden. pp. 47-57. American Society for Testing and Materials, Philadelphia, Pennsylvania (United States) Material dynamic elastic moduli can be readily obtained from a knowledge of the material's sound velocity(s) and density. One wellestablished ultrasonic technique for making the velocity measurements is the pulsed-wave transit-time technique. It is a versatile and potentially very accurate technique that can also assess the material elastic homogeneity and anisotropy. Here the many measurements and material factors affecting the precision of the method are addressed. A specific example of the effect of grain size on measurements in steel is presented in some detail. 46875 Sinclair, A.N.; Dickstein, P.A.; Spelt, J.K.; Segal, E.; Segal, Y. Acoustic resonance methods for measuring dynamic elastic modulus of adhesive b o n d s Dynamic Elastic Modulus Measurements in Materials, ASTM STP 1045. Edited by A. Wolfenden. pp. 162-179. American Society for Testing and Materials, Philadelphia, Pennsylvania (United States)
(1990) An investigation is made into acoustic resonance methods for measuring the dynamic elastic modulus of the adhesive layer in a bonded metal-tometal joint. Empirical studies have indicated that this parameter may be used to infer the cohesive strength of the bond; in theory, an accurate measurement of two or more resonant frequencies should give both the elastic modulus and thickness of the adhesive layer. The resonant frequencies of aluminum-to-aluminum adhesive joints were determined by both contact and immersion acoustic resonance techniques; receptance analysis was then used to determine the elastic modulus. Results were consistent with those achieved by time-of-flight measurements on bulk adhesive specimens. Based on these tests, inherent limitations of the Fokker Mark 11 Bondtester for assessing the cohesive strength of a bond were explored. 46658 Panakkal, J.P. Use of longitudinal ultrasonic velocity as a p r e d i c t o r of elastic moduli and density of sintered uranium dioxide IEEE Transactions, on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 38, No. 3, pp. 161-165 (May 1991) The values of elastic moduli and ultrasonic velocity of uranium dioxide as a function of pore volume fraction are compared with the predicted values of elasticity and self consistent scattering theories. Analysis of data shows that the longitudinal ultrasonic velocity may be used as a predictor of density and elastic moduli and that the relationship between the elastic moduli and longitudinal velocity is linear over a change of Young's modulus by 50%.
Karim, M.R.; Mal, A.K.; Bar-Cohen, Y. Determination of the elastic constants of composites through the inversion of leaky Lamb wave data
45932
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9A, pp. 109- I16. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) We describe an ultrasonic technique for the determination of the dynamic elastic moduli of fiber-reinforced composites through the analysis of guided wave speeds in laboratory specimens in the form of laminates. The wave speeds are measured by means of the leaky Lamb wave (LLW) technique. A functional relationship, called the dispersion equation, between the guided wave speed in the laminate, frequency and the dynamic elastic moduti of the material is derived through the use of a recently developed theoretical procedure.
Mignogna, R.B. Ultrasonic determination of elastic constants from oblique angles of incidence in non-symmetry planes
45622
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9B, pp. 1565- 1572. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) The most common technique to determine the elastic constants of anisotropic materials from ultrasonic wave speed measurements requires that the material be cut into samples such that particular symmetry directions can be accessed for normal incidence wave speed measurements. This is a destructive technique and is not feasible for thin or inhomogeneous
Wu, D.; Takahashi, S. Determination of the elastic constants of photoelastic material at freezing temperature by the method of caustics (In Japanese: English Abstracts)
47610
Journal o f JSNDi, Vol. 40, No. 8, pp. 530-535 (Aug. 1991) The photoelastic method of stress analysis is a powerful tool applied to a large number of engineering problems. It is very important to obtain the mechanical properties of photoelastic material experimentally, in this paper, an experimental technique to determine the modulus of transverse elasticity of photoelastic material at the freezing temperature is presented by usingthe method of caustics in combination with the photoelastic stress freezing method. It is possible to determine the modulus of transverse elasticity G with the simple experimental apparatus, and the result of Poisson's ratio obtained in this experiment is in good agreement with the result of the traditional method.
Wang, W.: Rokhlin, S.I. Nondestructive determination of elastic constants of ceramic composites
47243
Conference on Nondestructive Evaluation of Modern Ceramics, Columbus, Ohio (United States), 9-12 Jul. 1990. pp. 78-83 ASNT, (1991) The concept and technique of using ultrasonic antiresonance to detenmine elastic constants of thin-plate anisotropic media have been introduced by the authors. The technique is based on measuring zerotransmission angles and from these angles reconstructing the elastic constants, in this work, this technique is utilized to measure the elastic constants of ceramic composites of two kinds: composites with second phase oriented normal to the plane of the plate and thosewith second phases oriented in the plane of the plate. The materials are an anodized honeycomb AIO and fiber-reinforced SiC/AI composite.
Papadakis, E.P.; Patton, T.; Tsai, Y.-M.; Thompson, D.O.; Thompson, R.B. The elastic moduli of a thick composite as measured by ultrasonic bulk wave pulse velocity 46902
Journal of the Acoustical Society of America, Vol. 89, No. 6, pp. 2753- 2757 (Jun. 1991) One thick filament-wound composite in the form of a large thick-walled cylinder with locally orthorhombic symmetry has been measured by ultrasonic velocity to calculate its elastic moduli. The basic assumption was that small sections of the composite could be treated as a homogeneous body analogous to a crystal for ultrasonic propagation. The experimental work and the results as best expressing homogeneous body theory are presented. Because of the high anisotropy with the normal to the layers (the three-direction) much different from the axial and hoop directions, it was necessary to calculate slowness surfaces with approximate values of c and c in order to find the directions of the Poynting vectors to use in making actual measurements on c and c.
Castagnede, B,; Kim, K.Y.; Sachse, W.; Thompson, M,O. Determination of the elastic constants of anisotropic materials using laser-generated ultrasonic signals
46884
Journal o f Applied Physics, Vol. 70, No. I, pp. 150-157 (1 Jul. 1991) This paper presents the solution of the materials characterization problem in which the elastic constants of an anisotropic material are determined from ultrasonic wavespeed measurements made in nonprincipal directions of a specimen. The ultrasonic waves were generated via the point-source/point-receiver technique using a pulsed laser as a source and a miniature, point-like transducer as a receiver. In each waveform the arrivals of the quasi-longitudinal and the two quasi-shear bulk modes were measured and the elastic constants of the material were then recovered using an optimization algorithm. Experimental results are presented for a transversely isotropic, unidirectional fiberglass/polyester and a single crystal specimen of silicon. It was found that the nonlinear fit between the measured and the recovered longitudinal slowness values is excellent. Some discrepancies are observed in the data for the two shear modes. These are shown to be related to the complexity of the detected signals.
50
N D T & E International 1994 Volume 27, Number 1
46876 Blessing, G.V. The pulsed ultrasonic velocity m e t h o d for d e t e r m i n i n g material dynamic elastic moduli Dynamic Elastic Modulus Measurements in Materials, ASTM STP 1045. Edited by A. Wolfenden. pp. 47-57. American Society for Testing and Materials, Philadelphia, Pennsylvania (United States) Material dynamic elastic moduli can be readily obtained from a knowledge of the material's sound velocity(s) and density. One wellestablished ultrasonic technique for making the velocity measurements is the pulsed-wave transit-time technique. It is a versatile and potentially very accurate technique that can also assess the material elastic homogeneity and anisotropy. Here the many measurements and material factors affecting the precision of the method are addressed. A specific example of the effect of grain size on measurements in steel is presented in some detail. 46875 Sinclair, A.N.; Dickstein, P.A.; Spelt, J.K.; Segal, E.; Segal, Y. Acoustic resonance methods for measuring dynamic elastic modulus of adhesive b o n d s Dynamic Elastic Modulus Measurements in Materials, ASTM STP 1045. Edited by A. Wolfenden. pp. 162-179. American Society for Testing and Materials, Philadelphia, Pennsylvania (United States)
(1990) An investigation is made into acoustic resonance methods for measuring the dynamic elastic modulus of the adhesive layer in a bonded metal-tometal joint. Empirical studies have indicated that this parameter may be used to infer the cohesive strength of the bond; in theory, an accurate measurement of two or more resonant frequencies should give both the elastic modulus and thickness of the adhesive layer. The resonant frequencies of aluminum-to-aluminum adhesive joints were determined by both contact and immersion acoustic resonance techniques; receptance analysis was then used to determine the elastic modulus. Results were consistent with those achieved by time-of-flight measurements on bulk adhesive specimens. Based on these tests, inherent limitations of the Fokker Mark 11 Bondtester for assessing the cohesive strength of a bond were explored. 46658 Panakkal, J.P. Use of longitudinal ultrasonic velocity as a p r e d i c t o r of elastic moduli and density of sintered uranium dioxide IEEE Transactions, on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 38, No. 3, pp. 161-165 (May 1991) The values of elastic moduli and ultrasonic velocity of uranium dioxide as a function of pore volume fraction are compared with the predicted values of elasticity and self consistent scattering theories. Analysis of data shows that the longitudinal ultrasonic velocity may be used as a predictor of density and elastic moduli and that the relationship between the elastic moduli and longitudinal velocity is linear over a change of Young's modulus by 50%.
Karim, M.R.; Mal, A.K.; Bar-Cohen, Y. Determination of the elastic constants of composites through the inversion of leaky Lamb wave data
45932
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9A, pp. 109- I16. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) We describe an ultrasonic technique for the determination of the dynamic elastic moduli of fiber-reinforced composites through the analysis of guided wave speeds in laboratory specimens in the form of laminates. The wave speeds are measured by means of the leaky Lamb wave (LLW) technique. A functional relationship, called the dispersion equation, between the guided wave speed in the laminate, frequency and the dynamic elastic moduti of the material is derived through the use of a recently developed theoretical procedure.
Mignogna, R.B. Ultrasonic determination of elastic constants from oblique angles of incidence in non-symmetry planes
45622
Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9B, pp. 1565- 1572. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) The most common technique to determine the elastic constants of anisotropic materials from ultrasonic wave speed measurements requires that the material be cut into samples such that particular symmetry directions can be accessed for normal incidence wave speed measurements. This is a destructive technique and is not feasible for thin or inhomogeneous