Study Of Ultrasonic Methods For Nondestructive Measurement Of Residual Stress
Report Number: WADD TR 61-42 Part II
Author(s): Rollins, Fred R., Jr., Jones, Jerry Lee, Kobett, Donald R.
Corporate Author(s): Midwest Research Institute
Laboratory: Directorate of Materials and Processes
Date of Publication: 1963-01
Pages: 35
Contract: AF 33(616)-7058
DoD Project: 7360
DoD Task: 736002
Identifier: AD0299017
Abstract:
The study of stress-induced birefringence was continued in both polycrystalline and single crystal experiments.. The effect is explained on the basis of nonlinear elasticity theory. Experiments indicate that dislocation activity does not strongly affect results in polycrystalline specimens, however a pronounced influence may be observed in single crystals. Nonlinear elasticity theory was used to investigate the interaction of two intersecting, plane, elastic waves in a homogeneous, isotropic medium. A criterion for the occurrence of a strong scattered wave was derived and as formulated as a relationship between the second order elastic constants of the material, and the angle between the intersecting wave vectors, and the ratio of primary wave frequencies. The amplitude of the scattered wave is found to be proportional to the volume of interaction and dependent on the third order elastic constants of the material. Preliminary efforts to experimentally verify the theoretical predictions are described.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Rollins, Fred R., Jr., Jones, Jerry Lee, Kobett, Donald R.
Corporate Author(s): Midwest Research Institute
Laboratory: Directorate of Materials and Processes
Date of Publication: 1963-01
Pages: 35
Contract: AF 33(616)-7058
DoD Project: 7360
DoD Task: 736002
Identifier: AD0299017
Abstract:
The study of stress-induced birefringence was continued in both polycrystalline and single crystal experiments.. The effect is explained on the basis of nonlinear elasticity theory. Experiments indicate that dislocation activity does not strongly affect results in polycrystalline specimens, however a pronounced influence may be observed in single crystals. Nonlinear elasticity theory was used to investigate the interaction of two intersecting, plane, elastic waves in a homogeneous, isotropic medium. A criterion for the occurrence of a strong scattered wave was derived and as formulated as a relationship between the second order elastic constants of the material, and the angle between the intersecting wave vectors, and the ratio of primary wave frequencies. The amplitude of the scattered wave is found to be proportional to the volume of interaction and dependent on the third order elastic constants of the material. Preliminary efforts to experimentally verify the theoretical predictions are described.
Provenance: Lockheed Martin Missiles & Fire Control