Abstract: A hybrid fastener is provided in combination with a structural insert. The insert is disposed about a shank of the fastener at an unthreaded section. In another aspect, a sleeve surrounds the shank of the fastener and has apertures for receiving the insert therethrough. Methods of using the above-described hybrid fastener for securing workpieces are also disclosed.

Abstract: A hybrid fastener is provided in combination with a structural insert. The insert is disposed about a shank of the fastener at an unthreaded section. In another aspect, a sleeve surrounds the shank of the fastener and has apertures for receiving the insert therethrough. Methods of using the above-described hybrid fastener for securing workpieces are also disclosed.

Abstract: A multi-layer transparent composite detection technique includes producing two beams from a single, low-coherence source, a test beam and a reference beam, and scanning the reference beam to determine, with high precision, the depths of flaws (e.g., delaminations, bubbles, inclusions or other reflective or scattering objects) within a specimen or test object. The techniques combine light back-reflected or back-scattered from an internal flaw or interface with light in a reference path to identify such features and locations.

Abstract: A hybrid fastener is provided in combination with a structural insert. The insert is disposed about a shank of the fastener at an unthreaded section. In another aspect, a sleeve surrounds the shank of the fastener and has apertures for receiving the insert therethrough. Methods of using the above-described hybrid fastener for securing workpieces are also disclosed.

Abstract: A multi-layer transparent composite detection technique includes producing two beams from a single, low-coherence source, a test beam and a reference beam, and scanning the reference beam to determine, with high precision, the depths of flaws (e.g., delaminations, bubbles, inclusions or other reflective or scattering objects) within a specimen or test object. The techniques combine light back-reflected or back-scattered from an internal flaw or interface with light in a reference path to identify such features and locations.

Abstract: A hybrid fastener is provided in combination with a structural insert. The insert is disposed about a shank of the fastener at an unthreaded section. In another aspect, a sleeve surrounds the shank of the fastener and has apertures for receiving the insert therethrough. Methods of using the above-described hybrid fastener for securing workpieces are also disclosed.

Abstract: Presented is a speckle interferometer for measuring displacement of an optically irregular surface of a specimen having, a laser for producing a beam of coherent radiation, an adjustable polarizing beam splitter for dividing the radiation into a first portion of the radiation and into a second portion of the radiation. The reflected radiation is then passed through a pair of collimating lenses onto the optically rough surface of the specimen. The reflection off of the specimen is captured by an imaging system that processes the reflection to measure strains on the surface.

Abstract: A speckle interferometer for measuring displacement deformation, motion or strain of an optically irregular surface of a specimen is disclosed. The interferometer includes laser, a spatial filter for receiving radiation from the laser and converting it into a spherical beam and projecting it to the optically irregular surface of the specimen is located. A reference plate located in or near the second location for reflecting or scattering some or all the radiation to a fourth location, said reflection interfering with the reflection from the optically irregular surface to form a pattern of speckles. A camera and imaging system for measuring displacement and changes in intensity of the speckles is also included.