Abstract: A novel form of sandwich construction is disclosed. The lattice core sandh construction comprises of elongate lattice cells in side-by-side abutment, to present common, lengthwise flat sides that have facesheets co-cured thereto without any secondary bonding. Each lattice cell is formed by wrapping, in alterate patterns, fiber-reinforced, composite bands around commonly-shaped mandrels. Opppositely disposed face sheets are placed against flat sides and the construction co-cured. After co-curing, the mandrels are removed.

Abstract: A novel form of sandwich construction is disclosed. The lattice core sandh construction comprises of elongate lattice cells in side-by-side abutment, to present common, lengthwise flat sides that have facesheets co-cured thereto without any secondary bonding. Each lattice cell is formed by wrapping, in alterate patterns, fiber-reinforced, composite bands around commonly-shaped mandrels. Opppositely disposed face sheets are placed against flat sides and the construction co-cured. After co-curing, the mandrels are removed.

Abstract: An apparatus is disclosed for remotely detecting cracks of sub-critical lth which originate from stress raisers in structural materials, wherein the apparatus typically comprises a source of light, a continuous length of optical fiber to conduct the light, strain responsive devices coupled to the fiber and bonded to the structural member in close proximity to the stress raisers, and a light responsive detector which is optically coupled to the fiber in order to detect breaks in the fiber induced by either tensile or shear forces eminating from cracks around the stress raisers.