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Journal of the acoustical society of America
ABSTRACTS The abstracts survey, a regular feature of each issue of ULTRASONICS, contains recent patent information and reports of new literature in the field. Copies of original articles are best obtained by writing to the journal in which they appeared. The addresses of these journals can be found in reference books such as World List of Scientific and Technical Publications, Willings Press Guide, Newspaper Press Directory, or (for American journals) Ayers. ACUSTICA Cavitation measurement in a diffuse field Rieckmann, von P., Reibold, R. 28 (June 1973) 347-354
sound
In the tank of an ultrasonic cleaner a diffuse sound field was generated by a simple device and in this field the weightloss data for lead in water due to cavitation erosion was measured The dependence of the cavitation erosion on sonic radiation time, temperature and dissolved air content of the water was investigated.
Theoretical considerations backscatter Fay, von B. 28 (June 1973) 354-357
of ultrasound
Non-destructive structure testing with ultrasound using the impulse-echo method on materials with localized structure only yields the attenuation constant averaged over the sound path. Using theoretical considerations it is shown that by the method of ultrasonic backscatter one can calculate the change of backscatter and absorption coefficient in materials.
MATERIALS
EVALUATION
Ultrasonic procedures for predicting adhesive bond strength Rose, J. L, Meyer, P. A. 31 (June 1973) 109-114 Ultrasonic immersion and spectroscopic procedures are presented that are applicable for predicting and evaluating bond strength in an aluminium-to-aluminium step lap Scotch-Weld 2216 st~uctu~ai adhesive joint. A consideration of the non-linear shear stress distribution in the bond and the effects on evaluating a programmed flaw are included in the paper. It is shown that it is possible to establish a reasonable correlation between bond strength and some non-destructive testing parameter. Limitations of the methods are reviewed.
Ultrasonic measurements of cold-work percentages in type 3 16 stainless steel Reimann, K. J., Carson, N. J. 31 (July 1973) 128-144 Rayleigh critical-angle reflectivity constitutes a suitable method of determining cold-work percentages. Type 3 16 stainless
294
steel samples with a chemical composition that varied within the tolerances of ASTM standards and with different percentages of cold-work were fabricated and examined by the critical-angle reflectivity method. The variation of the critical angle is compared with the direction of cold working for different percentages of c. Id-work, and the effect of chemical variation on the measurement is discussed. Some ideas for modification of the laboratory test arrangement into an on-line inspection system are given.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Acoustic flows of Macedo, 53 (May
effects on gas bubbles in the viscous fluids and whole blood L. C., Yang, Wen-Jei 1973) 1327-1335
Gas-bubble behaviour in a liquid flowing inside a circular tube subjected to an acoustic pressure field is studied analytically and experimentally. Consideration is given to both viscous fluids and whole blood, with the effects of acoustic radiation and viscosity taken into account. Slug flow and laminar parabolic flow cases are treated. It is disclosed that the trajectory is strongly dependent upon the acoustic pressure amplitude, flow velocity, and liquid viscosity. By either increasing the acoustic pressure amplitude or decreasing the flow velocity or liquid viscosity, the bubble can be brought to a standstill in the fist halfwavelength from the tube entrance, at the node or antinode depending upon its size. Ultrasonic attenuation by spectrum analysis of pulses in buffer rods: Method and diffraction corrections Papadakis, E. P., Fowler, K. A., Lynnworth, L.C. 53 (May 1973) 1336-1343 A method is presented for measuring ultrasonic attenuation as a function of frequency by spectrum analysis of broadband echoes in a buffer/specimen system. Also presented is a new technique for diffraction corrections in this configuration. The buffer rod/spectrum analysis method with diffraction corrections is applied to three experiments to demonstrate its accuracy and versatility in measuring attenuation and defining transducer radiation/reception efficiency.
Ultrasonic attenuation as function temperature in a 1% carbon steel Tripathi, R. C., Verma, G. S. 53 (May 1973) 1344-1345
of
The ‘shouldered-specimen pulse-echo technique’ has been used to study the temperature dependence of ultrasonic attenuation (Yat 5 MHz in a 1% carbon steel. The attenuation-versus-temperature curve shows abrupt changes in its slope at 750 and 900°C respectively, after which the attenuation rises rapidly for temperatures up to 985°C. A qualitative explanation of the experimental curve is sought on the basis of Bhatia’s theory of scattering by the grains. The present work is the first of its kind to provide evidence for the growth of the austenitic grains with increasing values of temperature in the austenitic range. Analysis and measurement of ultrasound backscattering from an ensemble of scatterers excited by sinewave bursts Sigelmann, R. A., Reid, J. M. 53 (May 1973) 1351-1355 This paper develops a practical approximation for the backscattering of periodic bursts of sinewaves by a volume of randomly distributed scatterers. The approximation is applied to the measurement-of a ‘volumetric backscattering cross-section’ using a substitution method in which the RMS value of the gated backscattered signal is compared with the RMS value of a wave reflected from a target of known coefficient of reflection. It is shown that the signal backscattered from the ensemble depends on the attenuation of the wave in the volume and upon the burst and gate lengths. An equation to obtain the volumetric backscattering cross-section from experimental data is derived Impulse-response function corresponding to reflection from a region of continuous impedance change Wright, H. 53 (May 1973) 1356-1359 Acoustic reflection Tom a region of continuously varying specific acoustic impedance is characterized, in the linear circuit sense, by a unit reflection impulseresponse function R (f). It is shown that in the absence of attenuation and for modest impedance excursions, the impulseresponse function corresponding to reflection from a region which has continuously variable impedance along the incident axis is given by R(2t) = (dz/dt)/4z, where z(t) is the impedance proftle and t the acoustic travel time.
ULTRASONICS.
NOVEMBER
1973
sound
In the tank of an ultrasonic cleaner a diffuse sound field was generated by a simple device and in this field the weightloss data for lead in water due to cavitation erosion was measured The dependence of the cavitation erosion on sonic radiation time, temperature and dissolved air content of the water was investigated.
Theoretical considerations backscatter Fay, von B. 28 (June 1973) 354-357
of ultrasound
Non-destructive structure testing with ultrasound using the impulse-echo method on materials with localized structure only yields the attenuation constant averaged over the sound path. Using theoretical considerations it is shown that by the method of ultrasonic backscatter one can calculate the change of backscatter and absorption coefficient in materials.
MATERIALS
EVALUATION
Ultrasonic procedures for predicting adhesive bond strength Rose, J. L, Meyer, P. A. 31 (June 1973) 109-114 Ultrasonic immersion and spectroscopic procedures are presented that are applicable for predicting and evaluating bond strength in an aluminium-to-aluminium step lap Scotch-Weld 2216 st~uctu~ai adhesive joint. A consideration of the non-linear shear stress distribution in the bond and the effects on evaluating a programmed flaw are included in the paper. It is shown that it is possible to establish a reasonable correlation between bond strength and some non-destructive testing parameter. Limitations of the methods are reviewed.
Ultrasonic measurements of cold-work percentages in type 3 16 stainless steel Reimann, K. J., Carson, N. J. 31 (July 1973) 128-144 Rayleigh critical-angle reflectivity constitutes a suitable method of determining cold-work percentages. Type 3 16 stainless
294
steel samples with a chemical composition that varied within the tolerances of ASTM standards and with different percentages of cold-work were fabricated and examined by the critical-angle reflectivity method. The variation of the critical angle is compared with the direction of cold working for different percentages of c. Id-work, and the effect of chemical variation on the measurement is discussed. Some ideas for modification of the laboratory test arrangement into an on-line inspection system are given.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Acoustic flows of Macedo, 53 (May
effects on gas bubbles in the viscous fluids and whole blood L. C., Yang, Wen-Jei 1973) 1327-1335
Gas-bubble behaviour in a liquid flowing inside a circular tube subjected to an acoustic pressure field is studied analytically and experimentally. Consideration is given to both viscous fluids and whole blood, with the effects of acoustic radiation and viscosity taken into account. Slug flow and laminar parabolic flow cases are treated. It is disclosed that the trajectory is strongly dependent upon the acoustic pressure amplitude, flow velocity, and liquid viscosity. By either increasing the acoustic pressure amplitude or decreasing the flow velocity or liquid viscosity, the bubble can be brought to a standstill in the fist halfwavelength from the tube entrance, at the node or antinode depending upon its size. Ultrasonic attenuation by spectrum analysis of pulses in buffer rods: Method and diffraction corrections Papadakis, E. P., Fowler, K. A., Lynnworth, L.C. 53 (May 1973) 1336-1343 A method is presented for measuring ultrasonic attenuation as a function of frequency by spectrum analysis of broadband echoes in a buffer/specimen system. Also presented is a new technique for diffraction corrections in this configuration. The buffer rod/spectrum analysis method with diffraction corrections is applied to three experiments to demonstrate its accuracy and versatility in measuring attenuation and defining transducer radiation/reception efficiency.
Ultrasonic attenuation as function temperature in a 1% carbon steel Tripathi, R. C., Verma, G. S. 53 (May 1973) 1344-1345
of
The ‘shouldered-specimen pulse-echo technique’ has been used to study the temperature dependence of ultrasonic attenuation (Yat 5 MHz in a 1% carbon steel. The attenuation-versus-temperature curve shows abrupt changes in its slope at 750 and 900°C respectively, after which the attenuation rises rapidly for temperatures up to 985°C. A qualitative explanation of the experimental curve is sought on the basis of Bhatia’s theory of scattering by the grains. The present work is the first of its kind to provide evidence for the growth of the austenitic grains with increasing values of temperature in the austenitic range. Analysis and measurement of ultrasound backscattering from an ensemble of scatterers excited by sinewave bursts Sigelmann, R. A., Reid, J. M. 53 (May 1973) 1351-1355 This paper develops a practical approximation for the backscattering of periodic bursts of sinewaves by a volume of randomly distributed scatterers. The approximation is applied to the measurement-of a ‘volumetric backscattering cross-section’ using a substitution method in which the RMS value of the gated backscattered signal is compared with the RMS value of a wave reflected from a target of known coefficient of reflection. It is shown that the signal backscattered from the ensemble depends on the attenuation of the wave in the volume and upon the burst and gate lengths. An equation to obtain the volumetric backscattering cross-section from experimental data is derived Impulse-response function corresponding to reflection from a region of continuous impedance change Wright, H. 53 (May 1973) 1356-1359 Acoustic reflection Tom a region of continuously varying specific acoustic impedance is characterized, in the linear circuit sense, by a unit reflection impulseresponse function R (f). It is shown that in the absence of attenuation and for modest impedance excursions, the impulseresponse function corresponding to reflection from a region which has continuously variable impedance along the incident axis is given by R(2t) = (dz/dt)/4z, where z(t) is the impedance proftle and t the acoustic travel time.
ULTRASONICS.
NOVEMBER
1973