1. A system for monitoring electrical current passing through a cured bondline of a bonded joint, the system comprising:
a current sensor network embedded in an adhesive layer of a cured bondline of a structural assembly, including:
a plurality of inductive coils; and
a plurality of current sensor nodes electrically interconnecting the inductive coils to form a plurality of current sensor loops generating induced current in response to a magnetic field associated with an electrical current passing through the adhesive layer, the current sensor nodes generating current signals representative of the induced current;
a digital data communications network located external to the cured bondline and receiving the current signals from the current sensor nodes and detecting and monitoring electrical current passing through the cured bondline based on the current signals.
2. The system of claim 1, wherein:
the adhesive layer comprises an epoxy adhesive, a polyurethane adhesive, andor an acrylic adhesive.
3. The system of claim 1, wherein:
the structural assembly comprises a first structure formed of composite material, metallic material, or a combination thereof, bonded at the cured bondline to a second structure made of composite material, metallic material, or a combination thereof.
4. The system of claim 1, wherein:
the current sensor nodes are arranged such that the current sensor loops form a grid pattern in the cured bondline.
5. The system of claim 1, wherein:
at least some of the inductive coils are oriented generally orthogonally relative to one another such that at least one of the current sensor loops has a square shape defined by an inductive coil on each of four sides of the current sensor loop and having a current sensor node at each corner.
6. The system of claim 1, wherein:
the digital data communications network includes a data retrieval system and a data processing system;
the data retrieval system including one or more current integrators electrically connected to the current sensor nodes and integrating the induced current over time and generating one or more output signals; and
the data processing system determining a total electrical charge passing through the cured bondline based on the output signals.
7. The system of claim 1, wherein:
the inductive coils have an inductive coil height of no greater than approximately 0.020 inch, the inductive coil height being less than a bondline thickness of the cured bondline.
8. The system of claim 1, wherein:
the inductive coils have a flattened cross-sectional shape and an inductive coil height that is less than an inductive coil width.
9. The system of claim 8, wherein:
the flattened cross-sectional shape is a rectangular cross-sectional shape or an oval cross-sectional shape when the inductive coil is viewed from an end along a lengthwise direction of the inductive coil.
10. An aircraft, comprising:
a structural assembly including at least one bonded joint having an adhesive layer in a cured bondline bonding a first structure to a second structure;
a current sensor network embedded in an adhesive layer of the cured bondline, including:
a plurality of inductive coils generating induced current in response to a magnetic field associated with an electrical current passing through the adhesive layer; and
a plurality of current sensor nodes electrically interconnecting the inductive coils to form a plurality of current sensor loops, the current sensor nodes generating current signals representative of the induced current; and
a digital data communications network located external to the cured bondline and receiving the current signals from the current sensor network and detecting and monitoring electrical current passing through the cured bondline based on the current signals.
11. A method for monitoring electrical current passing through a cured bondline, comprising:
passing an electrical current through an adhesive layer of a cured bondline of a structural assembly, the electrical current having a magnetic field associated therewith, the adhesive layer containing a current sensor network including a plurality of inductive coils electrically interconnected at a plurality of current sensor nodes and forming a plurality of current sensor loops;
inducing an induced current in the current sensor loops in response to the magnetic field;
generating, at the current sensor nodes, current signals representative of the induced current;
transmitting the current signals to a digital data communications network located external to the cured bondline;
detecting and monitoring the electrical current using the digital data communications network based on the current signals.
12. The method of claim 11, wherein the step of detecting and monitoring the electrical current includes:
determining a relative magnitude of the electrical current passing through the adhesive layer based upon the current signals at the current sensor nodes; and
determining a distribution of the electrical current passing through the adhesive layer based upon the relative magnitude of the current signals.
13. The method of claim 11, wherein:
the electrical current is a result of a lightning strike on an aircraft containing the structural assembly.
14. The method of claim 11, wherein the steps of transmitting the current signals and detecting and monitoring the electrical current include:
transmitting the current signals from the current sensor nodes to one or more current integrators;
integrating, using the current integrators, the induced current over time to form output signals representative of the current signals; and
determining a total electrical charge passing through the cured bondline based on the output signals.
15. The method of claim 11, wherein the step of monitoring the electrical current include:
determining an electrical current profile of the electrical current passing through the adhesive layer.
16. The method of claim 11, wherein:
the adhesive layer comprises an epoxy adhesive, a polyurethane adhesive, andor an acrylic adhesive.
17. The method of claim 11, wherein:
the structural assembly comprises a first structure formed of composite material, metallic material, or a combination thereof, bonded at the cured bondline to a second structure made of composite material, metallic material, or a combination thereof.
18. The method of claim 11, wherein:
the current sensor nodes are arranged such that the current sensor loops form a grid pattern in the cured bondline.
19. The method of claim 11, wherein:
the inductive coils have an inductive coil height of no greater than approximately 0.020 inch, the inductive coil height being less than a bondline thickness of the cured bondline.
20. The method of claim 11, wherein:
the inductive coils have a flattened cross-sectional shape such that an inductive coil height is less than an inductive coil width.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A head chip comprising:
a chamber being defined on a substrate and having an end portion in a longitudinal direction that communicates with a nozzle opening;
an electrode provided on a sidewall of the chamber, in which a driving voltage is applied to the electrode so that a capacity within the chamber is changed to discharge ink filled therein from the nozzle opening; and
an ink chamber plate defining a common ink chamber communicating with said chamber is joined on the substrate, the common ink chamber is provided with a partitioning portion for partitioning the chamber and said common ink chamber;
wherein the partitioning portion is provided with a plurality of communicating holes that evenly divide a chamber longitudinal direction of the partitioning portion using a distance between said nozzle opening and a communicating hole establishing communication between the common ink chamber and the chamber and which is provided in the partitioning portion at a position close to the nozzle opening, and each of the plurality of communicating holes has the same opening ratio to an area of the partitioning portion; and
if a length in the longitudinal direction of the chamber is referred to as Y (mm) and an opening ratio of each communicating hole to the area of the partitioning portion is referred to as X (%), when a size of the communicating hole satisfying a relation of Y4.515.8 is referred to as Smin and a size of a communicating hole obtained by coupling the plurality of communicating holes to each other is referred to as Smax, there is obtained a relation of Smin size of communicating hole<Smax.
2. A head chip according to claim 1, wherein the partitioning portion is formed of a separate member.
3. A head chip according to claim 1, wherein the substrate is formed of a piezoelectric ceramic plate, and the chamber is defined by forming a groove in the piezoelectric ceramic plate.
4. A head chip according to claim 1, wherein the sidewalls are made of piezoelectric ceramic and are arranged on the substrate at a predetermined interval, and the chamber is defined between the sidewalls.
5. A head chip according to claim 4, wherein the common ink chamber is defined on the substrate, and the chamber and the common ink chamber communicate with each other at one end in the longitudinal direction of the chamber.