General Dynamics

About: General Dynamics is a company organization based out in Fairfax, Virginia, United States. It is known for research contribution in the topics: Signal & Propellant. The organization has 5722 authors who have published 5819 publications receiving 85768 citations. The organization is also known as: GD & General Dynamics Corporation.

Origami composite EMI/TEMPEST proof electronics module

Abstract: An origami printed circuit board comprises a rigid printed circuit board having a flexible conducting back secured to the bottom of the circuit board. The flexible back is constructed of alternating layers of flexible dielectric and conducting layers bonded together, where the conducting layers may include copper. The circuit board is then grooved in a predetermined manner with the grooves extending through the rigid circuit board, but not extending into the flexible conducting back. The entire circuit board/flexible back is then folded along the grooves in origami fashion to form an enclosure, or other designed shape, with the flexible back forming the outer walls of the shape. By coupling the electronic elements of the circuit board to the conducting layers of the flexible back, the flexible conducting back includes electronic circuit printed interconnections on the rigid board. A bottom conducting layer of the flexible back may be uncoupled to the electronic elements of the circuit board. When the origami printed circuit board is folded into shape, the bottom layer forms the board's outer wall and creates an EMI/TEMPEST shield. The shield also isolates RF frequency emissions.

Off-Axis Tensile Coupon Testing

Abstract: The off-axis tension test is frequently used to characterize the strength behavior of fibrous composite materials. This test is, ideally, uniform tension applied along a single axis. Because this axis does not coincide with one of the principal axes of the material, i.e., since the fibers are neither parallel nor perpendicular to this loading axis, the state of stress or strain referred to the principal axes of the material includes biaxial tension and shear. Such combined stress information is needed to assess the interpolation formulas or failure theories that are based upon 0-degree and 90-degree test specimens. Recently Pagano and Halpin [1] have pointed out that the shear coupling compliance S16 causes a non-uniform state of stress and strain in such tensile specimens when the ends are clamped, and furthermore this non-uniformity cannot be eliminated by simply allowing the ends of the specimen to rotate. An analytical solution was presented in [1] which indicated the aforementioned effect. This solution was obtained by integrating the equations for the plane stress condition from the linear theory of elasticity, but in order to solve the problem only the centerline at the specimen ends was rigidly clamped. Rizzo [2] has presented numerical solutions utilizing the finite element method to indicate the effects of full clamping and free rigid rotation of the ends of the specimens. These results are consistent with the closed form solutions of reference [1] ] and also with the experimental data presented by Wu and Thomas [3]. In the present note, further numerical results are presented which indicate the accuracy of the closed form solution presented in [1], and these results are further used to design a reasonable off-axis tensile coupon.

RF frequency spectrum analyzer subsystem

Abstract: A spectrum analyzer subsystem for analyzing the frequency content of an RF signal including an optical source means responsive to an RF signal for generating a plurality of intensity modulated optical signals and a filter means responsive to each one of the intensity modulated optical signals for providing a plurality of output optical signals each corresponding to a respective one of the intensity modulated optical signals. Each output optical signal corresponds in intensity to the frequency content of an RF signal within a different predetermined frequency bandwidth. Detector means, which is responsive to each output optical signal converts each output optical signal into a corresponding electrical signal.

Floating-point systolic array including serial processors

Abstract: A systolic array including chips having interface and timing and control circuitry and a plurality of processing elements. Each of the processing elements includes a floating-point serial processor and a plurality of data storage registers. The data storage registers in all of the elements communicate through a gridwork of data buses and all data registers and processing elements are programmed through a global bus. Software is simplified because algorithms are implemented directly in the new architecture.