Abstract: Apparatus and methods for injecting molten filler material into a hole. The method in accordance with one embodiment comprises: drilling a hole in a composite layer; heating filler material comprising an electrically conductive low-melting alloy to a molten state; inserting a nozzle having an internal channel system into the hole with a gap separating the nozzle and the hole; forcing molten filler material into, through and out of the internal channel system of the nozzle and into the gap; and retracting the nozzle from the hole. The nozzle may be rotary or not rotary.

Abstract: There is provided an LDE testing system. The system has a test chamber, a test article, and a capacitor to inject current into the test article, to create a spark, emitting a spark spectral signature, and having a spark light intensity. The system has a digitally-controlled reference light source operable to emit a reference light source spectral signature simulating an observed spark spectral signature of sparking in tested test articles, and having a reference light source light intensity equivalent to an observed spark light intensity. The system has a camera to capture an image of the spark spectral signature, spark light intensity, reference light source spectral signature, and reference light source light intensity, a controller to digitally control the digitally-controlled reference light source, and a computer system to receive the image from the camera, and determine a passing or failing result of an LDE testing criteria for the test article.

Abstract: A protective layer, a cell and a method provide radiation shielding. The cell and the protective layer formed of a plurality of cells provide radiation shielding, such as from protons and alpha particles having dangerously high energy levels, while being more lightweight than a conventional bulk HDPE protective layer. In the context of a protective layer, the protective layer includes a plurality of cells positioned proximate one another. The plurality of cells include at least a first cell. The first cell includes a cell body formed of an insulative material and extends between opposed first and second ends. The first cell also includes a conductive spherical portion proximate the first end of the cell body and an electrode disposed interior of the conductive spherical portion.

Abstract: The present disclosure relates systems and methods for treating various materials, such as carbon fiber reinforced polymer (CFRP), with a Joule heating process so as to reduce or eliminate a risk of sparks or explosion due to lightning strikes. The disclosure also relates to an aircraft component with structures that have undergone a Joule heating process by way of the systems and methods described herein. An example method includes providing an electrode array having a first and second electrode set. Each of the electrode sets includes one or more disk-shaped electrodes that are arranged in an interdigitated, concentric stack about a central axis. The method also includes causing the electrode array to contact a conductive material. The method additionally includes causing a current source to provide electrical current through the first electrode set and the second electrode set so as to heat at least a portion of a conductive material.

Abstract: A method for applying a coating on a surface of a lamination of plies of fiber-reinforced plastic material. The surface of the lamination includes exposed ends of reinforcement fibers. The method includes selecting an electrically conductive material that is abradable in a solid state by rubbing against the surface of the lamination having exposed ends of reinforcement fibers, and rubbing the electrically conductive material against the surface of the lamination to cause particles of electrically conductive material to be abraded and deposited on the surface of the lamination.

Abstract: A method for measuring a contact resistance at an interface of an electrically conductive coating and a cross-ply surface of a composite layer having electrically conductive fibers. The method includes: placing a dielectric coating of a sensing pad in contact with the composite layer or with the electrically conductive coating on the cross-ply surface of the composite layer; electrically connecting first and second input terminals of a comparator to the sensing pad and to one side of a capacitor respectively; electrically connecting another side of the capacitor to a fixed resistance; electrically connecting the fixed resistance to an electrically conductive body inserted in a hole in the composite layer; supplying an alternating current to the electrically conductive body and to the fixed resistance; and outputting a characteristic voltage signal if an amplitude of the input signal at the first input terminal is at least equal to an amplitude of the input signal at the second input terminal.

Abstract: A non-destructive testing system includes a test article interface and a reference article interface. The test article interface includes a connector to couple to a metal component of an article under test (AUT) and a connector to couple to a carbon fiber composite component of the AUT. The reference article interface includes a connector to couple to a metal component of a reference article (REF) and a connector to couple to a carbon fiber composite component of the REF. The system also includes sensors to generate signals based on voltage and current thermoelectrically induced between the test article interface and the reference article interface, where the current and the voltage are based on a temperature difference between the AUT and the REF. The system also includes a processor to generate, based on the signals, an output indicating whether the AUT is expected to pass a lightning strike test.

Abstract: Apparatus and methods for injecting molten filler material into a hole. The method in accordance with one embodiment comprises: drilling a hole in a composite layer; heating filler material comprising an electrically conductive low-melting alloy to a molten state; inserting a nozzle having an internal channel system into the hole with a gap separating the nozzle and the hole; forcing molten filler material into, through and out of the internal channel system of the nozzle and into the gap; and retracting the nozzle from the hole. The nozzle may be rotary or not rotary.

Abstract: A fastening device for coupling an assembly includes a fastener comprising a head, a threaded portion, and a shank extending between the head and the threaded portion. The fastening device also includes a coating formed around the fastener, wherein the coating is electrically conductive and comprises a varying thickness along the shank.

Abstract: A non-destructive testing system includes a test article interface and a reference article interface. The test article interface includes a connector to couple to a metal component of an article under test (AUT) and a connector to couple to a carbon fiber composite component of the AUT. The reference article interface includes a connector to couple to a metal component of a reference article (REF) and a connector to couple to a carbon fiber composite component of the REF. The system also includes sensors to generate signals based on voltage and current thermoelectrically induced between the test article interface and the reference article interface, where the current and the voltage are based on a temperature difference between the AUT and the REF. The system also includes a processor to generate, based on the signals, an output indicating whether the AUT is expected to pass a lightning strike test.

Abstract: A conductive fastener system for connecting a composite structure to a support structure includes a composite structure hole that extends through the composite structure and shares a common axis with a support structure hole that extends at least partially through the support structure. A fastener comprising a shank having an outer surface passes through the composite structure hole and at least partially through the support structure hole and provides an annular space between the outer surface of the shank and the inner surface of the composite structure hole. The annular space is filled with a conductive paste that comprises conductive particles suspended in a bonding agent.

Abstract: A system and method for creating an optimized composite laminate structure containing a plurality of plies. The system has a processor and a memory, including an application interface. The application interface, when executed by the processor, is configured to operably: receive an input file having one or more of a maximum number of plies, design variables, material properties, and design constraints; determine an initial layup sequence defining parameters of a fiber orientation angle for each ply, and a total percentage of plies at a given fiber orientation angle; iteratively adjust the parameters, until an optimum set of parameters is obtained that achieves one or more predetermined margins of safety, and that achieves optimization of the composite laminate structure; and generate an output file for creating a layup, according to the parameters. The system further has a layup system for creating the optimized composite laminate structure.

Abstract: Methods of digital communication utilizing entangled qubits are disclosed. The communication methods exploit selective entanglement swapping to transfer an entangled state between a sending device and a receiving device. Each device includes pairs of qubits that are independently entangled with pairs of qubits in the other device. By selectively entangling the qubits within a pair in the sending device, the qubits of the corresponding pair in the receiving device also are selectively entangled. When the qubits are entangled, they are projected onto a particular entangled state type. Though no information may be transferred through selective entanglement of one qubit pair, the disclosed methods determine whether a set of pairs of qubits are entangled by determining whether the distribution of pairs is a correlated or uncorrelated distribution (a probabilistic approach) and transform the distribution type to a classical bit of data to transfer classical bits in a qubit-efficient approach.

Abstract: A fastener providing protection against damage to an aircraft resulting from lightning strikes includes an elongated shaft having a head disposed at an upper end thereof, one, the other, or both of the shaft and the head containing a circumferential groove disposed proximate an intersection of the shaft and the head, a lower surface of the head including a plurality of grooves extending radially outward from the circumferential groove and terminating at an outer periphery of the lower surface. A tubular sleeve is disposed concentrically about the shaft and has a plurality of through-slots disposed therein. Each through-slot has a lower end disposed above a lower end of the sleeve, and an upper end disposed in fluid communication with the circumferential groove, such that superheated gases and particles generated in interfaces between the fastener and the adjacent skin due to lightning strikes are vented harmlessly to the atmosphere through the channels and grooves.

Abstract: Methods of digital communication utilizing entangled qubits are disclosed. The communication methods exploit selective entanglement swapping to transfer an entangled state between a sending device and a receiving device. Each device includes pairs of qubits that are independently entangled with pairs of qubits in the other device. By selectively entangling the qubits within a pair in the sending device, the qubits of the corresponding pair in the receiving device also are selectively entangled. When the qubits are entangled, they are projected onto a particular entangled state type. Though no information may be transferred through selective entanglement of one qubit pair, the disclosed methods determine whether a set of pairs of qubits are entangled by determining whether the distribution of pairs is a correlated or uncorrelated distribution (a probabilistic approach) and transform the distribution type to a classical bit of data to transfer classical bits in a qubit-efficient approach.

Abstract: Digital communication systems utilizing entangled qubits are disclosed. The disclosed systems and component sending devices and receiving devices exploit selective entanglement swapping to transfer an entangled state between the sending device and the receiving device. Each device includes pairs of qubits that are independently entangled with pairs of qubits in the other device. By selectively entangling the qubits within a pair in the sending device, the qubits of the corresponding pair in the receiving device also are selectively entangled. When the qubits are entangled, they are projected onto a particular entangled state type. Though no information may be transferred through selective entanglement of one qubit pair, systems of the present disclosure determine whether a set of pairs of qubits are entangled by determining whether the distribution of pairs is a correlated or uncorrelated distribution (a probabilistic approach) and transform the distribution type to a classical bit of data.

Abstract: A method including receiving a joint parameter for a joint between at least two composite structural components, a ply stackup for each of the at least two composite structural components and an electromagnetic effect parameter in a controller, iteratively processing with the controller, the joint parameter and the ply stackup and outputting an optimized joint parameter based on at least a convergence of an electromagnetic effect resistance of the joint and the at least two composite structural components, and changing, with the controller, a value of one or more of the joint parameters and the ply stackup during the iterative processing to reach the convergence of the electromagnetic effect resistance.

Abstract: A method includes applying a current to a specimen to deposit a material on the specimen. The method also includes determining a quantity of the material deposited at multiple locations of the specimen and determining anisotropic conductive characteristics of the specimen based on the quantity of the material deposited at the multiple locations on the specimen.

Abstract: Digital communication systems utilizing entangled qubits are disclosed. The disclosed systems and component sending devices and receiving devices exploit selective entanglement swapping to transfer an entangled state between the sending device and the receiving device. Each device includes pairs of qubits that are independently entangled with pairs of qubits in the other device. By selectively entangling the qubits within a pair in the sending device, the qubits of the corresponding pair in the receiving device also are selectively entangled. When the qubits are entangled, they are projected onto a particular entangled state type. Though no information may be transferred through selective entanglement of one qubit pair, systems of the present disclosure determine whether a set of pairs of qubits are entangled by determining whether the distribution of pairs is a correlated or uncorrelated distribution (a probabilistic approach) and transform the distribution type to a classical bit of data.

Abstract: A fastener providing protection against damage to an aircraft resulting from lightning strikes includes an elongated shaft having a head disposed at an upper end thereof, one, the other, or both of the shaft and the head containing a circumferential groove disposed proximate an intersection of the shaft and the head, a lower surface of the head including a plurality of grooves extending radially outward from the circumferential groove and terminating at an outer periphery of the lower surface. A tubular sleeve is disposed concentrically about the shaft and has a plurality of through-slots disposed therein. Each through-slot has a lower end disposed above a lower end of the sleeve, and an upper end disposed in fluid communication with the circumferential groove, such that superheated gases and particles generated in interfaces between the fastener and the adjacent skin due to lightning strikes are vented harmlessly to the atmosphere through the channels and grooves.