Accession Number:

AD0669065

Title:

MOIRE INTERFEROMETRY WITH EMBEDDED GRIDS, EFFECT OF OPTICAL REFRACTION,

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s):

Report Date:

1968-04-01

Pagination or Media Count:

39.0

Abstract:

Optical refraction resulting from refractive index gradients present in nonhomogeneously stressed models is investigated as a limitation on the usefulness of moire interferometry employing embedded grids. Estimates of apparent displacements caused by internal refraction are derived for representative static and dynamic problems Boussinesqs problem, and the problem of a spherically expanding pulse, respectively. Refraction effects are found to be far larger in the dynamic case. Apparatus for dynamic moire interferometry employing single-spark, high-speed photography is briefly described, and observations of transient motions in Plexiglas models loaded nondestructively by pellet impact are discussed. The moire results are compared with motion histories obtained using a capacitive transducer. The moire data exhibit significant anomalies whose basic features agree fairly well with the predicted refraction effects for the aforementioned case of a spherically expanding pulse. Author

Subject Categories:

  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE