Abstract: Methods are described for the use of conformable eddy-current sensors and sensor arrays for characterizing residual stresses and applied loads in materials. In addition, for magnetizable materials such as steels, these methods can be used to determine carbide content and to inspect for grinding burn damage. The sensor arrays can be mounted inside or scanned across the inner surface of test articles and hollow fasteners to monitor stress distributions. A technique for placing eddy-current coils around magnetizable fasteners for load distribution monitoring is also disclosed.

Abstract: Methods are described for the use of conformable eddy-current sensors and sensor arrays for characterizing residual stresses and applied loads in materials. In addition, for magnetizable materials such as steels, these methods can be used to determine carbide content and to inspect for grinding burn damage. The sensor arrays can be mounted inside or scanned across the inner surface of test articles and hollow fasteners to monitor stress distributions. A technique for placing eddy-current coils around magnetizable fasteners for load distribution monitoring is also disclosed.

Abstract: In a system for electroplating a printed circuit board in which multiple spray orifices are provided in arrays on opposite sides of the circuit board, and multiple vacuum orifices are interspersed symmetrically and midway between adjacent spray orifices, a mounting means is provided for rapid and accurate locating of the printed circuit board in two selectively offset alternative positions to facilitate forming an electroplated layer of uniform thickness. The printed circuit board is supported from an elongate copper bar, with two alignment members mounted to opposite ends of the bar. A pair of saddles are fixed with respect to the tank containing the electrolyte. Each of the saddles has two V-shaped mounting surfaces conforming to the alignment members for a nesting engagement.

Abstract: Structural joint members for a space frame system with a node joint having threaded apertures, structural strut members with threaded end sections, and a connecting member. The connecting member includes an elongatged threaded bolt, a fixed nut locked on one bolt end with a set screw, and a jam nut threadably engaging the other bolt end. The bolt threadably engages the node joint and the strut threaded end section with the fixed nut secured against the node joint and the jam nut secured against the strut end section to lock the structural joint members together. A snap-on cap covers the connecting member.

Abstract: A joist girder construction includes connecting ties which connect adjacent ends of joist girders at a point where they are supported. The ties include a non-welded zone to afford plastic elongation of the tie. The ties create an axial connection force between the top chords to reduce the force a load causes within the joist girder to thus reduce the size of the upper and lower joist chords to minimize overall weight and expense.