Carbon fiber composite panel with integrated fault detection and health monitoring

Abstract

This invention relates to a carbon fiber composite plate with integrated fault detection and health monitoring. One composite plate includes a first carbon fiber layer and a first glass fiber layer. A first carbon fiber sensor includes a first plurality of carbon fiber bundles. The composite plate includes a second glass fiber layer and a second carbon fiber layer. The first carbon fiber sensor is disposed between the first glass fiber layer and the second glass fiber layer. The first carbon fiber layer and the second carbon fiber layer are respectively disposed adjacent to the first glass fiber layer and the second glass fiber layer.

Description

[0001] Government license to use

[0002] This invention was made with government support under patent number DE-EE0009204 granted by the U.S. Department of Energy. The U.S. government holds certain rights in this invention. Technical Field

[0003] introduction

[0004] The information provided in this section is for the purpose of presenting the overall context of this disclosure. The works of the currently attributed inventors, to the extent described in this section, and in all aspects of that description which at the time of filing may not be regarded as prior art, are neither expressly nor implicitly considered prior art to this disclosure.

[0005] This disclosure relates to carbon fiber composite materials, and more particularly to systems and methods for monitoring the failures and health of carbon fiber composite structures. Carbon fiber composite materials refer to any fiber-reinforced polymer composite material containing carbon fibers. Background Technology

[0006] Carbon fiber composites are increasingly being used as structural components in vehicles, aircraft, and other applications. Some composite panels are positioned in locations susceptible to damage during operation. For example, carbon fiber composite panels can be used to construct battery casings for electric vehicles. In some applications, the bottom surface of the battery casing may be exposed beneath the electric vehicle and potentially subject to damage from road debris. In some cases, significant structural damage may occur without significant visible damage, and / or visible damage may occur without significant structural damage. Assessing damage to carbon fiber composite panels to diagnose the need for repair or replacement is difficult, time-consuming, and expensive. Summary of the Invention

[0007] A composite board includes a first carbon fiber layer and a first glass fiber layer. A first carbon fiber sensor includes a first plurality of carbon fiber bundles. The composite board includes a second glass fiber layer and a second carbon fiber layer. The first carbon fiber sensor is disposed between the first glass fiber layer and the second glass fiber layer. The first carbon fiber layer and the second carbon fiber layer are respectively disposed adjacent to the first glass fiber layer and the second glass fiber layer.

[0008] Among other features, the first plurality of carbon fiber bundles are connected in parallel to a first node and a second node extending from the composite plate. Each of the first plurality of carbon fiber bundles of the first carbon fiber sensor has a unique resistance.

[0009] Among other features, the second carbon fiber sensor includes a second plurality of carbon fiber bundles connected in parallel to third and fourth nodes extending from the composite plate. The composite plate includes a third glass fiber layer. The second carbon fiber layer is disposed between the second and third glass fiber layers. Each of the second plurality of carbon fiber bundles of the second carbon fiber sensor has a unique resistance.

[0010] Among other features, the first carbon fiber sensor is arranged to rotate relative to the second carbon fiber sensor. One or more discrete resistors are connected to one or more of the first plurality of carbon fiber bundles to change the resistance of said one or more of the first plurality of carbon fiber bundles.

[0011] A damage monitoring system includes a composite plate. A controller is configured to: measure the equivalent resistance of a first carbon fiber sensor; and based on the equivalent resistance, identify one or more broken carbon fiber bundles among the first plurality of carbon fiber bundles.

[0012] Among other features, the controller is configured to identify the location of a broken carbon fiber bundle within the composite panel. The controller determines the change in the equivalent resistance of a first carbon fiber sensor relative to a predetermined resistance, and selectively identifies one or more broken carbon fibers within the first plurality of carbon fiber bundles in response to the change in equivalent resistance.

[0013] A composite board includes: a first carbon fiber layer; a first carbon fiber sensor comprising N mixed bundles, each bundle including multiple carbon fiber filaments surrounded by multiple glass fiber filaments, where N is an integer greater than or equal to 1; and a second carbon fiber layer. The first carbon fiber sensor is disposed between the first carbon fiber layer and the second carbon fiber layer.

[0014] Among other characteristics, N is greater than 1, and the N hybrid bundles are connected in parallel to the first and second nodes. Each of the N hybrid bundles of the first carbon fiber sensor has a unique resistance.

[0015] Among other features, the second carbon fiber sensor includes M hybrid bundles connected in parallel to the third and fourth nodes, where M is an integer greater than 1. The second carbon fiber sensor is disposed between the first and second carbon fiber layers. The first carbon fiber sensor rotates relative to the second carbon fiber sensor.

[0016] A damage monitoring system includes a composite plate. A controller is configured to: measure the equivalent resistance of a first carbon fiber sensor; and based on the equivalent resistance, identify one or more broken strands among N mixed bundles. The controller is also configured to identify the locations of several broken strands among the N mixed bundles in the composite plate. Furthermore, the controller is configured to: determine the change in the equivalent resistance of the first carbon fiber sensor relative to a predetermined resistance; and selectively identify one or more broken strands among the N mixed bundles in response to the change in equivalent resistance.

[0017] A health monitoring system includes: a composite plate; and a controller configured to: measure the equivalent resistance of N mixed bundles, where N equals 1; determine the change in the equivalent resistance of at least one of the N mixed bundles relative to a predetermined resistance; and calculate the health status of the composite plate in response to the change in equivalent resistance.

[0018] A health monitoring system includes a hybrid composite panel comprising multiple carbon fiber bundles and multiple glass fiber bundles. A controller is configured to: measure the equivalent resistance of at least one of the carbon fiber bundles; determine the change in the equivalent resistance of said at least one carbon fiber bundle relative to a predetermined resistance; and calculate the health status of the hybrid composite panel in response to the change in equivalent resistance.

[0019] Among other features, at least one of the carbon fiber bundles is insulated from the plurality of glass fiber bundles. The controller is further configured to identify when the at least one of the carbon fiber bundles breaks based on equivalent resistance.

[0020] The present invention also discloses the following technical solutions:

[0021] 1. A composite panel comprising:

[0022] First carbon fiber layer;

[0023] First glass fiber layer;

[0024] A first carbon fiber sensor, comprising a first plurality of carbon fiber bundles;

[0025] The second glass fiber layer; and

[0026] Second carbon fiber layer,

[0027] The first carbon fiber sensor is disposed between the first glass fiber layer and the second glass fiber layer, and the first carbon fiber layer and the second carbon fiber layer are respectively disposed adjacent to the first glass fiber layer and the second glass fiber layer.

[0028] 2. The composite board according to technical solution 1, wherein:

[0029] The first plurality of carbon fiber bundles are connected in parallel to a first node and a second node extending from the composite plate; and

[0030] Each of the first plurality of carbon fiber bundles in the first carbon fiber sensor has a unique resistance.

[0031] 3. The composite board according to technical solution 2, further comprising:

[0032] A second carbon fiber sensor, comprising a second plurality of carbon fiber bundles connected in parallel to a third and a fourth node extending from the composite plate; and

[0033] The third glass fiber layer,

[0034] The second carbon fiber layer is disposed between the second glass fiber layer and the third glass fiber layer.

[0035] 4. The composite plate according to technical solution 3, wherein each of the second plurality of carbon fiber bundles of the second carbon fiber sensor has a unique resistance.

[0036] 5. The composite plate according to technical solution 3, wherein the first carbon fiber sensor is arranged to rotate relative to the second carbon fiber sensor.

[0037] 6. The composite plate according to technical solution 1 further includes one or more discrete resistors connected to one or more of the first plurality of carbon fiber bundles to change the resistance of the one or more of the first plurality of carbon fiber bundles.

[0038] 7. A damage monitoring system, comprising:

[0039] The composite plate according to technical solution 1; and

[0040] The controller is constructed as follows:

[0041] Measure the equivalent resistance of the first carbon fiber sensor; and

[0042] The equivalent resistance is used to identify one or more broken carbon fiber bundles in the first plurality of carbon fiber bundles.

[0043] 8. The damage monitoring system according to technical solution 7, wherein the controller is configured to identify the location of a broken strand of the carbon fiber bundle in the composite plate.

[0044] 9. The damage monitoring system according to technical solution 7, wherein the controller is configured to: determine the change in the equivalent resistance of the first carbon fiber sensor relative to a predetermined resistance; and selectively identify one or more of the first plurality of carbon fiber bundles that have broken in response to the change in the equivalent resistance.

[0045] 10. A composite panel comprising:

[0046] First carbon fiber layer;

[0047] A first carbon fiber sensor includes N hybrid bundles, each bundle comprising multiple carbon fiber filaments surrounded by multiple glass fiber filaments, where N is an integer greater than or equal to 1; and

[0048] A second carbon fiber layer, wherein the first carbon fiber sensor is disposed between the first carbon fiber layer and the second carbon fiber layer.

[0049] 11. The composite plate according to technical solution 10, wherein:

[0050] N is greater than 1;

[0051] The N hybrid bundles are connected in parallel to the first node and the second node; and

[0052] Each of the N mixed bundles of the first carbon fiber sensor has a unique resistance.

[0053] 12. The composite plate according to technical solution 10, further comprising:

[0054] The second carbon fiber sensor comprises M hybrid bundles connected in parallel to the third and fourth nodes, where M is an integer greater than 1; and

[0055] The second carbon fiber sensor is disposed between the first carbon fiber layer and the second carbon fiber layer.

[0056] 13. The composite plate according to technical solution 12, wherein the first carbon fiber sensor rotates relative to the second carbon fiber sensor.

[0057] 14. A damage monitoring system, comprising:

[0058] The composite plate according to technical solution 11; and

[0059] The controller is constructed as follows:

[0060] Measure the equivalent resistance of the first carbon fiber sensor; and

[0061] The equivalent resistance is used to identify one or more broken strands among the N mixed bundles.

[0062] 15. The damage monitoring system according to technical solution 14, wherein the controller is configured to identify the locations of several broken strands among the N mixed bundles in the composite plate.

[0063] 16. The damage monitoring system according to technical solution 14, wherein the controller is configured to: determine the change in the equivalent resistance of the first carbon fiber sensor relative to a predetermined resistance; and selectively identify one or more broken strands among the N mixed bundles in response to the change in the equivalent resistance.

[0064] 17. A health monitoring system, comprising:

[0065] The composite plate according to technical solution 10; and

[0066] The controller is constructed as follows:

[0067] Measure the equivalent resistance of the N mixed beams, where N equals 1; and

[0068] Determine the change in the equivalent resistance of at least one of the N mixed bundles relative to a predetermined resistance; and

[0069] The health status of the composite plate is calculated in response to the change in the equivalent resistance.

[0070] 18. A health monitoring system, comprising:

[0071] Hybrid composite panels, comprising:

[0072] Multiple carbon fiber bundles; and

[0073] Multiple glass fiber bundles; and

[0074] The controller is constructed as follows:

[0075] Measure the equivalent resistance of at least one of the carbon fiber bundles;

[0076] Determine the change in the equivalent resistance of at least one of the carbon fiber bundles relative to a predetermined resistance; and

[0077] The health status of the hybrid composite plate is calculated in response to the change in the equivalent resistance.

[0078] 19. The health monitoring system according to technical solution 18, wherein at least one of the carbon fiber bundles is insulated from the plurality of glass fiber bundles.

[0079] 20. The health monitoring system according to claim 18, wherein the controller is further configured to identify when at least one of the carbon fiber bundles breaks based on the equivalent resistance.

[0080] Further applicability of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0081] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0082] Figure 1 and Figure 2 This is a perspective view showing an example of a carbon fiber composite panel according to the present disclosure;

[0083] Figure 3A This is a cross-sectional view of an electrically insulated carbon fiber bundle including a radial inner region and a radial outer region, according to the present disclosure;

[0084] Figure 3B It is a cross-sectional view of a hybrid composite plate comprising carbon fiber bundles and glass fiber bundles according to the present disclosure, wherein one or more of the carbon fiber bundles serve as carbon fiber sensors;

[0085] Figure 4 and Figure 5 This is a perspective view showing an example of a carbon fiber composite panel according to the present disclosure;

[0086] Figure 6A and Figure 6B This is an electrical schematic diagram illustrating an example of parallel-connected carbon fiber bundles according to this disclosure;

[0087] Figure 7A and Figure 7B This is an electrical schematic diagram illustrating examples of carbon fiber sensors according to the present disclosure, which include bundles of carbon fibers connected in parallel and include discrete resistors.

[0088] Figure 8 It is a graph that plots the resistance of a carbon fiber bundle as a function of stress / strain, according to this disclosure;

[0089] Figures 9A to 9D The illustration shows a carbon fiber bundle arranged in a variable number of loops according to the present disclosure;

[0090] Figure 10 It is a graph according to this disclosure that plots the resistance variation of a carbon fiber bundle as a function of stress / strain for different numbers of loops;

[0091] Figure 11This is a functional block diagram of an example vehicle control system according to the present disclosure, which includes a fault location module and / or a health estimation module;

[0092] Figure 12 and Figure 13 This is a flowchart illustrating an example of a method for identifying the location of damage in a composite plate according to this disclosure; and

[0093] Figure 14 This is a perspective view of an electric vehicle battery casing with multiple carbon fiber sensors embedded according to the present disclosure.

[0094] In the accompanying drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Implementation

[0095] This disclosure relates to systems and methods for monitoring the health of composite panels. In some examples, the carbon fiber composite panel includes: a carbon fiber outer layer; a glass fiber layer acting as an insulation layer; and one or more carbon fiber sensors, each comprising a single carbon fiber sensor or multiple bundles of carbon fibers connected in parallel. In other examples, the composite panel includes: a carbon fiber outer layer; and a carbon fiber sensor comprising one or more mixed bundles, said mixed bundles comprising carbon fiber filaments insulated by glass fiber filaments.

[0096] The carbon fiber sensor acts as a structural element and senses stress / strain and / or damage to the composite panel. The equivalent resistance of the carbon fiber sensor is measured periodically or on an event-based basis. In some examples, the resistance of the carbon fiber bundles in the carbon fiber sensor is variable and specific. The controller detects changes in the equivalent resistance, and these changes are used to identify the location of stress / strain, damage, and / or damage, as described further below. The controller identifies faults and their locations based on the equivalent resistance of the carbon fiber sensor.

[0097] In other examples, the hybrid composite panel comprises carbon fiber bundles and glass fiber bundles. The controller estimates the health of the composite panel by comparing the measured equivalent resistance to a predetermined resistance corresponding to an undamaged carbon fiber bundle. Strain in the composite structure is monitored by measuring the resistance of the carbon fiber bundles. The equivalent resistance increases with the strain experienced by the carbon fiber bundles. The increase in resistance due to stress / strain can be instantaneous or permanent. When one of the carbon sensor bundles completely breaks, the carbon sensor bundle becomes an open circuit and its resistance becomes infinite.

[0098] The load cycles and micro-damage experienced by the composite panel during its service life cause a gradual and permanent increase in resistance. Therefore, the residual strength (or life) of the component can be predicted by measuring the changes in resistance relative to the currently measured equivalent resistance of the carbon fiber bundles and the equivalent resistance before damage.

[0099] Now for reference Figure 1 and Figure 2 Examples of composite panels 50 and 78 are shown respectively. Figure 1 In this composite board 50, there are layers stacked together and a resin binding the layers together. The layers stack includes a carbon fiber layer 60. A glass fiber layer 64 is arranged adjacent to the carbon fiber layer 60. A carbon fiber sensor 66, comprising multiple bundles made of carbon fiber bundles, is located between the glass fiber layers 64 and 68.

[0100] The stitch 67 can be used to connect the carbon fiber sensor 66 in the composite panel (e.g., to the glass fiber layer, another part of the carbon fiber sensor, and / or the carbon fiber layer). In some examples, the stitch 67 is made of an insulating material, such as nylon. The carbon fiber layer 70 is arranged adjacent to the glass fiber layer 68.

[0101] The carbon fiber sensor 66 comprises multiple bundles made of carbon fiber bundles and connected in parallel to a first node and a second node. The carbon fiber bundles may extend from the first and second nodes to the edge of the composite plate for connection to a controller. Glass fiber layers 64 and 68 provide insulation between the carbon fiber sensor 66 and the carbon fiber layers 60 and 70. The controller (described further below) measures the equivalent resistance of the carbon fiber sensor 66 and identifies the location of damage based on changes in the equivalent resistance.

[0102] exist Figure 2 In this composite panel 78, carbon fiber layer 60, glass fiber layer 64, carbon fiber sensor 80 (comprising multiple carbon fiber bundles connected in parallel), glass fiber layer 82, carbon fiber sensor 66, glass fiber layer 68, and carbon fiber layer 70 are included. In other words, additional carbon fiber sensors and an insulation layer (glass fiber layer 86) are added. In some examples, carbon fiber sensor 66 is arranged in a position rotated relative to carbon fiber sensor 80 to allow for more precise damage localization at one or more junctions between two or more damaged legs (carbon fiber bundles). In some examples, carbon fiber sensor 66 is arranged laterally relative to carbon fiber sensor 80.

[0103] In the examples described above, the carbon fiber bundles in carbon fiber sensors 66 and 80 are exposed. Glass fiber layers 64, 68, and 82 provide insulation between carbon fiber sensors 66 and 80 and carbon fiber layers 60 and 70. In some examples, carbon fiber sensors 66 and 80 are arranged laterally to each other to allow for the definition of a grid that provides positional information along two orthogonal directions.

[0104] When the bundles of carbon fiber sensors are connected in parallel, the equivalent resistance (R) of the circuit is... eq The reciprocal of ) is equal to the sum of the reciprocals of the resistances in each leg, or If resistors R1, R2, ..., and R... N Sufficiently specific and associated with different locations within the composite plate, the breakage of one strand in a bundle (effectively increasing the resistance from a predetermined value to infinity) will cause a specific change in the measured equivalent resistance relative to the equivalent resistance of an undamaged carbon fiber sensor. These specific changes in resistance can be used to identify the damaged bundle. Since the location of the damaged bundle is known, the location of the damage is also determined. If two carbon fiber sensors are used and their sensor bundles are orthogonally oriented to each other, stress / strain may damage the two orthogonally oriented carbon fiber bundles. The junction between the two damaged carbon fiber bundles may be the location of the damage.

[0105] Now for reference Figure 3A Instead of the exposed carbon fibers described above, an insulated carbon fiber bundle 94 can be used. Since the carbon fiber bundle is insulated, the glass fiber layer can be omitted. The insulated carbon fiber bundle 94 comprises a radially inner region 94-1 and a radially outer region 94-2. Multiple carbon fibers 96 are located in the radially inner region 94-1, and multiple glass fibers 98 are located in the radially outer region 94-2, to insulate the carbon fibers 96 located in the radially inner region 94-1. In some examples, the ratio of carbon fibers to glass fibers is in the range of 10:90 to 50:50.

[0106] Now for reference Figure 4 and Figure 5 This shows the use of Figure 3A An example of an insulated composite plate made of carbon fiber bundles. In Figure 4 In this composite board 100, a carbon fiber layer 104, a carbon fiber sensor 106 (comprising multiple carbon fiber bundles connected in parallel), and a carbon fiber layer 108 are included. The carbon fiber sensor 106 is sandwiched between carbon fiber layers 104 and 108. Figure 5 In this configuration, composite panel 114 includes a second carbon fiber sensor 116, which is disposed between carbon fiber layers 104 and 108 to allow for additional sensing, as will be further described below. Because the carbon fiber bundles are insulated, the glass fiber layer can be omitted without causing a short circuit.

[0107] exist Figure 3B The image shows a cross-sectional view of the hybrid composite plate 91. In some examples of monitoring the health of the composite plate, the equivalent resistance is measured periodically at predetermined time intervals during operation to detect the instantaneous stress / strain experienced by the composite plate. In some cases, the composite plate can recover to a smaller stress / strain state. In other examples, the stress / strain can be permanent. In some examples, the carbon fiber bundle comprises 1,000 to 50,000 carbon fiber filaments.

[0108] The hybrid composite board 91 comprises a mixture of carbon fiber bundles 93 and glass fiber bundles 95. One or more of the carbon fiber bundles 93 (e.g., carbon fiber bundle 93') can be used as a sensor bundle. The glass fiber bundle 95 surrounding the carbon fiber bundle 93' (which acts as the sensor bundle) serves as an electrical insulator. Figure 3B In this system, carbon fiber bundles 93 and 93' and glass fiber bundle 95 serve as load-bearing structural materials and sensor systems, which saves on manufacturing costs.

[0109] When the carbon fiber bundles 93' of the hybrid composite plate 91 experience stress / strain, the resistance of the carbon fiber bundles 93' increases (but does not increase to infinity). As the hybrid composite plate 91 experiences stress / strain, its service life decreases. The measured change in equivalent resistance due to stress / strain can also be used to estimate the service life of the hybrid composite plate 91 based on the increase in resistance (typically less than that of a broken bundle).

[0110] Now for reference Figure 6A and Figure 6B An example of a carbon fiber sensor comprising carbon fiber bundles connected in parallel is shown. Only a single circuit is needed to measure the equivalent resistance of such a multi-bundle sensor. Figure 6A In the composite plate 120, a carbon fiber sensor 122 is included, which comprises components connected in parallel and having different resistances R. C1 R C2 ... and R CN Carbon fiber bundles. The carbon fibers in a carbon fiber bundle typically have a predetermined resistance per unit length. Therefore, longer carbon fiber bundles have a higher resistance compared to shorter carbon fiber bundles. Figure 6B In the diagram, the parallel fiber bundles of the carbon fiber sensor 124 are shown to have different lengths and are connected to a first node and a second node located within the composite plate. These nodes are connected to a controller located outside the composite plate via the carbon fiber bundles.

[0111] exist Figure 7A In the composite plate 120, a carbon fiber sensor 126 is included, which comprises components connected in parallel and having different resistances R. C1 R C2 ... and R CN Carbon fiber bundles. One or more discrete resistors R D1 R D2 ...can be connected in series and / or in parallel to one or more carbon fiber bundles to change the resistance of the bundle / leg. Discrete resistors can be used to increase the separation between the unique equivalent resistances that arise due to damage and increase the possibility of detection.

[0112] In some examples, discrete resistors are embedded in composite board 120. Figure 7B In the composite plate 120, a carbon fiber sensor 128 is included, which comprises components connected in parallel and having different resistances R. C1 R C2 ... and R CN Carbon fiber bundles. One or more discrete resistors R D1 R D2 ...can be connected to one or more carbon fiber bundles, as described above.

[0113] Now for reference Figure 8 The diagram conceptually illustrates the change in resistance R of a carbon fiber bundle as a function of stress / strain S in the composite plate. When the carbon fiber bundle is subjected to stress / strain S, the resistance R of the carbon fiber bundle increases in a predictable manner before fracture. As strain S increases to the point where the carbon fiber filaments in the bundle begin to break, the resistance R of the bundle increases sharply. Once the carbon fiber bundle is completely broken, the resistance R increases to infinity. As will be further described below, the increase in resistance R caused by stress / strain S (before fracture) can be measured and used to predict the health or remaining operational life of the carbon fiber sensor.

[0114] Now for reference Figures 9A to 9D The carbon fiber bundle is shown as comprising a variable number of loops. The carbon fiber bundle can be arranged into one or more loops within the composite plate. More loops will provide an additional resistance value corresponding to the same strain, and as a result, the sensitivity of the carbon fiber sensor increases, as described below.

[0115] Now for reference Figure 10 The graphs conceptually illustrate the change in resistance of a carbon fiber bundle as a function of strain for different numbers of loops. A single, straight carbon fiber bundle is shown at 90. A carbon fiber bundle with two loops is shown at 92. Carbon fiber bundles including three and four loops are shown at 94 and 96, respectively. As can be seen, the change in resistance of the carbon fiber bundle due to strain increases with the number of loops. In other words, carbon fiber bundles with a higher number of loops provide greater sensitivity and allow for more accurate stress / strain measurements, thus allowing for more accurate health estimations.

[0116] In some examples, the equivalent resistance of the carbon fiber bundles is measured at predetermined time intervals (e.g., less than or equal to 1 s, 5 s, 10 s, 60 s, etc.) during the drive cycle, the stress / strain of the carbon fiber sensor is calculated, and stress / strain events at various levels are calculated and stored. The controller assesses the health status of at least corresponding portions of the composite panel based on the number of events at various stress / strain levels. In some examples, stress / strain levels are weighted, and the health status is determined based on a score determined based on the weights and counts at these stress / strain levels.

[0117] Now for reference Figure 11 The vehicle control system 200 includes multiple controllers 210-1, 210-2, ..., and 210-N (collectively referred to as controllers 210). Each of the controllers 210-1, 210-2, ..., and 210-N includes fault location modules 214-1, 214-2, ..., and 214-C (collectively referred to as fault location modules 214) and / or health estimation modules 216-1, 216-2, ..., and 216-N (collectively referred to as health estimation modules 216). Each of the controllers 210 is connected to one or more carbon fiber sensors 220. When a given area of ​​the composite panel is monitored by two or more carbon fiber sensors, some of the controllers 210 may be connected to more than one carbon fiber sensor 220, such as... Figure 2 and Figure 4 As shown in the image.

[0118] The vehicle control system further includes a vehicle controller 234 and a telematics system 240. The vehicle controller 234 can be connected to a display 238 to notify a user of a fault. A controller 210 is connected to the vehicle controller 234 via a bus 221 (such as a Controller Area Network (CAN) bus). In some examples, upon detecting a fault or estimating a health condition, optionally, the vehicle controller 234 sends a message (including a fault or health condition estimate) via the telematics system 240 to a remote server operated by the vehicle manufacturer or other party, enabling service to be scheduled and / or customer contact to be initiated. In some examples, the health estimate also includes an estimate of remaining lifespan.

[0119] The fault location module 214 periodically measures the resistance of the carbon fiber sensor. Each strand in the carbon fiber sensor bundle has a unique resistance value. Due to these unique resistance values, the location of the fault within the composite board can be determined when one or more strands in the carbon fiber bundle of the carbon fiber sensor fail.

[0120] Now for reference Figure 12 and Figure 13 The flowchart illustrates an example of a method for identifying damage locations in a composite plate. Figure 12 Method 300 is illustrated below. At 310, the equivalent resistance of the undamaged carbon fiber sensor is determined. At 314, j damage conditions or arrangements are identified (where j is an integer greater than 1). At 318, for each of the j damage conditions, the equivalent resistance of the carbon fiber sensor is determined. At 322, a damage vector or table is determined, which includes the expected resistance change (relative to the undamaged carbon fiber bundle) for each of the j damage conditions.

[0121] exist Figure 13 Method 330 is shown in the diagram. At 334, the measured resistance value of the equivalent resistance of the carbon fiber sensor is read. At 338, the method determines whether... Where δ is the confidence level of the measured value, and R0 em It is the measured equivalent resistance, and R e This is the predetermined equivalent resistance of the undamaged sensor circuit. If 338 is false, damage is detected at 342. At 344, the method finds the damage vector or table. (And the corresponding location on the composite structure). At 330, the method identifies one or more damage locations based on comparison. If 338 is true (i.e., no damage is detected), the method waits at 340 for a predetermined period of time and then returns to 334.

[0122] In some examples where measurements are taken of continuous carbon fiber bundles rather than parallel circuits, the measured equivalent resistance may exceed the range ( However, it remains within a predetermined threshold (less than infinity). This state corresponds to microscopic damage due to stress / strain, but not fracture. In this case, the measured equivalent resistance can be used to estimate the health condition or remaining lifetime of the composite plate. In some examples, the measured equivalent resistance is used to access an operation lookup table, which outputs the health condition or remaining lifetime of the composite plate. In other examples, the function generates the health condition or remaining lifetime of the composite plate in response to the measured equivalent resistance, a previously stored value, and / or the rate of change of resistance.

[0123] Now for reference Figure 14 The composite panel 408 includes sidewalls 410 and a bottom surface 412, which may be exposed to damage due to road debris or other conditions. A plurality of carbon fiber sensors 420-1, 420-2, ..., and 420-P are arranged along the bottom surface 412. The plurality of carbon fiber sensors 420-1, 420-2, ..., and 420-P are connected to one or more controllers (not shown).

[0124] The foregoing description is merely illustrative in nature and is in no way intended to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, specification, and the following claims. It should be understood that one or more steps within the method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, while each of the embodiments described above is described as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the arrangement of one or more embodiments with each other remains within the scope of this disclosure.

[0125] Spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “joined,” “linked,” “adjacent,” “closely adjacent,” “on top of,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing the relationship between the first and second components in the above disclosure, the relationship can be a direct relationship in which no other intervening components exist between the first and second components, or it can be an indirect relationship (spatially or functionally) between the first and second components. As used herein, at least one of the phrases A, B, and C should be interpreted as referring to the logic (A OR B OR C) using non-exclusive logic OR, and should not be interpreted as referring to “at least one of A, at least one of B, and at least one of C.”

[0126] In the accompanying drawings, the direction of the arrows generally illustrates the flow of information of interest (such as data or instructions). For example, when components A and B exchange various types of information, but the information transmitted from component A to component B is relevant to the illustration, the arrow may point from component A to component B. This unidirectional arrow does not imply that no other information is transmitted from component B to component A. Furthermore, for information sent from component A to component B, component B may send a request for the information to component A or receive acknowledgment of the information.

[0127] In this application (including the definitions below), the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the described functionality; or combinations of some or all of the above, such as in a system-on-a-chip.

[0128] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module of this disclosure may be distributed among multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In further examples, a server (also referred to as a remote or cloud) module may perform a function on behalf of a client module.

[0129] The term "code" as used above can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" covers a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" covers a processor circuit that, in combination with additional processor circuits, executes some or all of the code from one or more modules. The reference to multiple processor circuits covers multiple processor circuits on a discrete die, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term "shared memory circuit" covers a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" covers a memory circuit that, in combination with additional memory, stores some or all of the code from one or more modules.

[0130] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not cover transient electrical or electromagnetic signals propagating through a medium (such as a carrier wave); therefore, the term computer-readable medium can be considered tangible and non-transitory. Non-limiting examples of non-transitory, tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0131] The apparatus and methods described in this application can be implemented, in part or in whole, by a special-purpose computer created by causing a general-purpose computing mechanism to perform one or more specific functions embodied in a computer program. The function blocks, flowchart components, and other elements described above serve as software specifications that can be converted into computer programs through the routine work of skilled technicians or programmers.

[0132] A computer program includes processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. A computer program may also include or depend on stored data. A computer program may encompass a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of a special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0133] Computer programs may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code executed by an interpreter; and (v) source code compiled and executed by a just-in-time (JIT) compiler, etc. As an example only, source code may be written in languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, JavaScript®, HTML5 (Hypertext Markup Language version 5), Ada, ASP (Dynamic Server Web Pages), PHP (PHP: Hypertext Preprocessing Language), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

1. A composite panel, comprising: First carbon fiber layer; First glass fiber layer; A first carbon fiber sensor, comprising a first plurality of carbon fiber bundles; Second glass fiber layer; as well as Second carbon fiber layer, The first carbon fiber sensor is disposed between the first glass fiber layer and the second glass fiber layer, and the first carbon fiber layer and the second carbon fiber layer are respectively disposed adjacent to the first glass fiber layer and the second glass fiber layer.

2. The composite board according to claim 1, wherein: The first plurality of carbon fiber bundles are connected in parallel to a first node and a second node extending from the composite plate; and Each of the first plurality of carbon fiber bundles in the first carbon fiber sensor has a unique resistance.

3. The composite board according to claim 2, further comprising: The second carbon fiber sensor includes a second plurality of carbon fiber bundles connected in parallel to a third node and a fourth node extending from the composite plate. as well as The third glass fiber layer, The second carbon fiber layer is disposed between the second glass fiber layer and the third glass fiber layer.

4. The composite board according to claim 3, wherein, Each of the second plurality of carbon fiber bundles in the second carbon fiber sensor has a unique resistance.

5. The composite board according to claim 3, wherein, The first carbon fiber sensor is arranged to rotate relative to the second carbon fiber sensor.

6. The composite plate according to claim 1, further comprising one or more discrete resistors connected to one or more of the first plurality of carbon fiber bundles to change the resistance of the one or more of the first plurality of carbon fiber bundles.

7. A damage monitoring system, comprising: The composite board according to claim 1; as well as The controller is constructed as follows: Measure the equivalent resistance of the first carbon fiber sensor; as well as The equivalent resistance is used to identify one or more broken carbon fiber bundles in the first plurality of carbon fiber bundles.

8. The damage monitoring system according to claim 7, wherein, The controller is configured to identify the location of a broken strand of the carbon fiber bundle in the composite plate.

9. The damage monitoring system according to claim 7, wherein, The controller is configured to: determine the change in the equivalent resistance of the first carbon fiber sensor relative to a predetermined resistance; And in response to the change in the equivalent resistance, selectively identify one or more of the first plurality of carbon fiber bundles that have broken.

10. A composite panel comprising: First carbon fiber layer; A first carbon fiber sensor includes N mixed bundles, each bundle comprising multiple carbon fiber filaments surrounded by multiple glass fiber filaments, where N is an integer greater than or equal to 1. as well as A second carbon fiber layer, wherein the first carbon fiber sensor is disposed between the first carbon fiber layer and the second carbon fiber layer.

11. The composite panel according to claim 10, wherein: N is greater than 1; The N hybrid bundles are connected in parallel to the first node and the second node; and Each of the N mixed bundles of the first carbon fiber sensor has a unique resistance.

12. The composite panel according to claim 10, further comprising: The second carbon fiber sensor comprises M hybrid bundles connected in parallel to the third and fourth nodes, where M is an integer greater than 1; and The second carbon fiber sensor is disposed between the first carbon fiber layer and the second carbon fiber layer.

13. The composite board according to claim 12, wherein, The first carbon fiber sensor rotates relative to the second carbon fiber sensor.

14. A damage monitoring system, comprising: The composite board according to claim 11; as well as The controller is constructed as follows: Measure the equivalent resistance of the first carbon fiber sensor; as well as The equivalent resistance is used to identify one or more broken strands among the N mixed bundles.

15. The damage monitoring system according to claim 14, wherein, The controller is configured to identify the locations of several broken strands among the N mixed bundles in the composite plate.

16. The damage monitoring system according to claim 14, wherein, The controller is configured to: determine the change in the equivalent resistance of the first carbon fiber sensor relative to a predetermined resistance; And in response to the change in the equivalent resistance, selectively identify one or more of the N mixed bundles that have broken.

17. A health monitoring system, comprising: The composite board according to claim 10; as well as The controller is constructed as follows: Measure the equivalent resistance of the N mixed beams, where N equals 1; as well as Determine the change in the equivalent resistance of at least one of the N mixed bundles relative to a predetermined resistance; as well as The health status of the composite plate is calculated in response to the change in the equivalent resistance.

18. A health monitoring system, comprising: Hybrid composite panels, comprising: Multiple carbon fiber bundles; and Multiple glass fiber bundles; and The controller is constructed as follows: Measure the equivalent resistance of at least one of the carbon fiber bundles, wherein the at least one of the carbon fiber bundles is surrounded by a glass fiber bundle; Determine the change in the equivalent resistance of at least one of the carbon fiber bundles relative to a predetermined resistance; and The health status of the hybrid composite plate is calculated in response to the change in the equivalent resistance.

19. The health monitoring system according to claim 18, wherein, At least one of the carbon fiber bundles is insulated from the plurality of glass fiber bundles.

20. The health monitoring system according to claim 18, wherein, The controller is further configured to identify when at least one of the carbon fiber bundles breaks based on the equivalent resistance.

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