A structural health monitoring method and device, electronic equipment and storage medium

Abstract

This invention discloses a structural health monitoring method, device, electronic device, and storage medium. The method includes: determining a first parameter value for a health condition corresponding to a structural unit in a target structure, and determining a second parameter value for a damage condition corresponding to the structural unit; determining a damage index of the structural unit based on the first and second parameter values; generating a damage index histogram corresponding to the target structure based on the damage indices of each structural unit; and identifying structural units in the target structure that are damaged based on the damage index histogram. The technical solution provided by this invention can achieve rapid, reliable, and highly sensitive capture of instantaneous dynamic impact responses during aircraft operation, thereby enabling high-precision and high-sensitivity detection of multiple potential defects and damages in aircraft structures.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of structural damage diagnosis technology, and in particular to a structural health monitoring method, device, electronic device and storage medium. Background Technology

[0002] Online monitoring of aircraft structural health is a damage diagnosis method based on dynamic response testing. It includes signal extraction and acquisition as well as signal processing, and boasts numerous advantages such as relative simplicity, low cost, and the ability to achieve real-time structural monitoring. Its basic principle is to utilize measured data of structural dynamic response and, through system parameter identification technology, determine changes in structural parameters to ascertain whether damage exists, its location, and its extent. Based on structural damage monitoring, this includes five levels: first, determining the presence of damage; second, determining the location of damage; third, determining the degree and type of damage; fourth, estimating the remaining structural life; and fifth, assessing the overall structural integrity.

[0003] In related technologies, structural damage health monitoring methods for aircraft structures involve using instruments such as eddy current, ultrasound, and X-rays when the aircraft is grounded, and some structures even require disassembly for testing. Alternatively, related technologies can perform structural health monitoring while the aircraft is in operation, but this can only detect one location of damage. Summary of the Invention

[0004] This invention provides a structural health monitoring method, device, electronic device, and storage medium, which can quickly, reliably, and sensitively capture instantaneous dynamic impact responses during aircraft operation, thereby enabling high-precision and high-sensitivity detection of multiple potential defects and damages in the aircraft structure.

[0005] In a first aspect, embodiments of the present invention provide a structural health monitoring method, the method comprising: determining a first parameter value of a health condition corresponding to a structural unit in a target structure, and determining a second parameter value of a damage condition corresponding to the structural unit;

[0006] The damage index of the structural unit is determined based on the first parameter value and the second parameter value;

[0007] Based on the damage index of each structural unit, a damage index bar chart corresponding to the target structure is generated.

[0008] Based on the damage index histogram, structural units with damage in the target structure are identified.

[0009] Secondly, embodiments of the present invention also provide a structural health monitoring device, the device comprising: a parameter value determination module, configured to determine a first parameter value of a health condition corresponding to a structural unit in a target structure, and to determine a second parameter value of a damage condition corresponding to the structural unit;

[0010] The damage index determination module is used to determine the damage index of the structural unit based on the first parameter value and the second parameter value;

[0011] The damage index histogram generation module is used to generate a damage index histogram corresponding to the target structure based on the damage index of each structural unit.

[0012] The damaged structural unit determination module is used to determine the structural units with damage in the target structure based on the damage index histogram.

[0013] Thirdly, embodiments of the present invention also provide an electronic device, the device comprising:

[0014] One or more processors;

[0015] Storage device for storing one or more programs.

[0016] When the one or more programs are executed by the one or more processors, the one or more processors implement the structural health monitoring method as described in any one of the embodiments of the present invention.

[0017] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the structural health monitoring method as described in any one of the embodiments of the present invention.

[0018] The technical solution provided by this invention determines a first parameter value for the healthy operating condition corresponding to a structural unit in a target structure, and a second parameter value for the damaged operating condition corresponding to the structural unit; determines the damage index of the structural unit based on the first and second parameter values; generates a damage index histogram corresponding to the target structure based on the damage index of each structural unit; and identifies the structural units in the target structure that have damage based on the damage index histogram. By implementing this solution, it is possible to quickly, reliably, and sensitively capture instantaneous dynamic impact responses during aircraft operation, thereby enabling high-precision and high-sensitivity detection of multiple potential defects and damages in the aircraft structure. Attached Figure Description

[0019] Figure 1a This is a flowchart of a structural health monitoring method provided in an embodiment of the present invention;

[0020] Figure 1b This is a schematic diagram of a planar truss structure provided in an embodiment of the present invention;

[0021] Figure 1c This is a bar chart of the damage index of the target structure under damage condition two, considering damping, provided in an embodiment of the present invention.

[0022] Figure 1d This is a bar chart of the damage index of the target structure under damage condition two without considering damping, provided by an embodiment of the present invention.

[0023] Figure 2a This is a damage index histogram of the target structure under damage conditions without considering damping, provided by an embodiment of the present invention.

[0024] Figure 2b This is a damage index histogram of the target structure under damage conditions, considering damping, provided in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of a structural health monitoring device provided in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of an electronic device structure provided in an embodiment of the present invention. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0028] Figure 1a This is a flowchart of a structural health monitoring method provided in an embodiment of the present invention. The method can be executed by a structural health monitoring device, which can be implemented in software and / or hardware and can be configured in an electronic device for structural health monitoring. The method is applied to scenarios where damaged structural units are identified. Figure 1a As shown, the technical solution provided by the embodiments of the present invention specifically includes:

[0029] S110: Determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and determine the second parameter value of the damaged working condition corresponding to the structural unit.

[0030] The target structure can be an aircraft truss structure or other truss structures. The target structure can be composed of structural elements, such as Timoshenko beam elements. A healthy operating condition is one where no structural element in the target structure is damaged and its stiffness is not reduced. A damaged operating condition is one where at least one structural element in the target structure is damaged, resulting in a reduction in stiffness. The strain value can indirectly reflect the degree of stiffness reduction of the corresponding structural element. The first parameter value can be the vibration response result of the structural element under the healthy operating condition, and the second parameter value can be the vibration response result of the structural element under the damaged operating condition.

[0031] In one feasible implementation, optionally, before determining the first parameter value of the healthy operating condition corresponding to the structural unit in the target structure and the second parameter value of the damage operating condition corresponding to the structural unit, the method further includes: constructing a healthy finite element model corresponding to the target structure under the healthy operating condition and constructing a damage finite element model corresponding to the target structure under the damage operating condition; correspondingly, determining the first parameter value of the healthy operating condition corresponding to the structural unit in the target structure and determining the second parameter value of the damage operating condition corresponding to the structural unit includes: determining the first parameter value of the healthy operating condition corresponding to the structural unit in the target structure based on the healthy finite element model and determining the second parameter value of the damage operating condition corresponding to the structural unit based on the damage finite element model.

[0032] Specifically, the target structure can be a planar truss structure. A healthy finite element model corresponding to the target structure under healthy operating conditions and a damaged finite element model corresponding to the target structure under damaged operating conditions can be constructed. Based on the healthy and damaged finite element models, the first parameter values ​​for the healthy operating conditions and the second parameter values ​​for the damaged operating conditions corresponding to the structural elements in the target structure are determined respectively. For example... Figure 1b As shown, taking a target structure comprising 21 structural elements as an example, a finite element model corresponding to the target structure is constructed in a planar coordinate system. The direction along the rod is the X-axis, the direction perpendicular to the rod is the Y-axis, and a structural element is defined between two nodes; for example, structural element S3 is located between node 3 and node 4. First, the damage index of the first structural element in the target structure is determined based on the damage index formula. Then, subroutines are called to perform iterative calculations until the damage indices of all structural elements in the target structure are calculated.

[0033] Taking the healthy finite element model of the target structure under healthy operating conditions as an example, the modal vector Φ of the target structure under healthy operating conditions can be obtained using ground resonance tests. Simultaneously, the natural frequency vector Ω of the target structure under healthy operating conditions can be determined using ground resonance tests. M', D', K', and B are then determined through calculations using the healthy finite element model. o , q and w. Among them, B o Let be the impact vector of the target structure under healthy operating conditions, w be the load amplification factor of the target structure under healthy operating conditions, and q be the displacement vector corresponding to the target structure under healthy operating conditions. M', D', and K' are the mass vector, damping vector, and stiffness vector respectively calculated using the healthy finite element model of the target structure under healthy operating conditions. For the equations of motion... The solution is performed to determine the eigenvalues, thus obtaining the natural frequency vector Ω' of the target structure under healthy operating conditions. Simultaneously, the equations can be calculated... The eigenvalues ​​are used to obtain the modal vector Φ' of the target structure under healthy conditions. By correcting Φ' with Φ and Ω' with Ω respectively, a healthy finite element model that is completely consistent with the target structure under healthy conditions is obtained, and the final mass vector M, final stiffness vector K, and final damping vector D of the target structure under healthy conditions are determined. The specific solution methods for each variable can refer to the solution process of the impact response equation of the finite element model in related technical dynamics. The construction process of the damage finite element model corresponding to the target structure under damaged conditions can refer to the construction process of the healthy finite element model corresponding to the target structure under healthy conditions.

[0034] S120: Determine the damage index of the structural unit based on the first parameter value and the second parameter value.

[0035] The damage index characterizes the degree of damage to structural units within the target structure. The damage index of a structural unit can be determined by extracting the difference between its first and second parameter values. Furthermore, by calling subroutines, the damage indices of other structural units within the target structure are calculated, thereby pinpointing the location of damage within the target structure.

[0036] In one feasible implementation, optionally, determining the damage index of the structural unit based on the first parameter value and the second parameter value includes:

[0037] The damage index of the structural unit is determined based on the following formula:

[0038]

[0039] Among them, DI k The damage index is the k-th structural unit in the target structure. The first parameter value of the k-th structural unit in the target structure; The second parameter value of the k-th structural unit in the target structure;

[0040] in,

[0041] Where i represents the i-th mode, and n represents the total number of modes of the target structure under healthy operating conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under healthy operating conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under healthy operating conditions. The comprehensive strain value of the k-th structural unit in the target structure under healthy operating conditions in the i-th mode;

[0042] in,

[0043] Wherein, l represents the total number of modes of the target structure under damage conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under damage conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under damage conditions. The comprehensive strain value of the k-th structural unit in the target structure under the damage condition is the i-th mode.

[0044] Specifically, the specific implementation process for determining the damage index of the first structural unit in the target structure based on the damage index formula is as follows: calculate the first parameter value corresponding to the first structural unit, then calculate the second parameter value corresponding to the first structural unit, and then determine the damage index of the first structural unit in the target structure based on the first parameter value and the second parameter value.

[0045] For example, the first parameter value corresponding to the first structural unit is jointly determined by the modal weighting coefficients of each order and the comprehensive strain values ​​of each order corresponding to the first structural unit in the target structure under healthy operating conditions. Figure 1b As shown, each node of each structural unit in the target structure has three degrees of freedom, while node 1 (fixed) and node 7 have only X and Y degrees of freedom, resulting in a total of 31 degrees of freedom for the target structure. By introducing the modal vectors corresponding to the target structure under healthy operating conditions, the number of degrees of freedom can be reduced to obtain the total number of modes. The total number of modes in the target structure under healthy operating conditions can be 10 or 20, depending on actual needs. Specifically, the modal weighting coefficients of each order of the first structural unit in the target structure under healthy operating conditions are jointly determined by the modal vectors of the target structure under healthy operating conditions and the weighting coefficients of the first structural unit in the target structure under healthy operating conditions. The comprehensive strain values ​​of each order corresponding to the first structural unit in the target structure under healthy operating conditions are jointly determined by the impact vectors of each mode, the damping of each mode, the natural frequencies of each mode, and the modal strain corresponding to the first structural unit in the target structure under healthy operating conditions.

[0046] The second parameter value corresponding to the first structural unit is determined by the modal weighting coefficients and the comprehensive strain values ​​of each order of the first structural unit in the target structure under the damage condition. Introducing the modal vectors corresponding to the target structure under the damage condition allows for a reduction in the number of degrees of freedom of the target structure under the damage condition, resulting in the total number of modes. The total number of modes of the target structure under the damage condition can be 10 or 20, depending on actual needs. The total number of modes of the target structure under the damage condition must be consistent with the total number of modes of the target structure under the healthy condition. Specifically, the modal weighting coefficients of the first structural unit in the target structure under the damage condition are determined by the modal vectors of the target structure under the damage condition and the weighting coefficients of the first structural unit in the target structure under the healthy condition. The comprehensive strain values ​​of each order of the first structural unit in the target structure under the damage condition are determined by the impact vectors of each mode, the damping of each mode, the natural frequencies of each mode, and the modal strains of each mode corresponding to the first structural unit in the target structure under the damage condition.

[0047] Therefore, by iteratively calculating the damage index of structural units in the target structure using the damage index formula, the damage index of all structural units in the target structure can be determined, thus providing data preparation for determining structural units with multiple damages in the target structure.

[0048] In one feasible implementation, optionally, the comprehensive strain value of the k-th structural unit in the target structure under the i-th mode under the target working condition is determined based on the following formula:

[0049]

[0050] Among them, G ki Let be the comprehensive strain value of the k-th structural unit in the target structure under the i-th mode of the target working condition. Let ζ be the i-th component of the modal impact vector of the target structure under the target working condition. i Let ω be the damping of the i-th mode of the target structure under the target operating condition. i Let be the natural frequency of the i-th mode of the target structure under the target operating condition. The element in the k-th row and i-th column of the modal displacement-strain transformation vector represents the modal strain of the k-th structural unit in the target structure under the target working condition in the i-th mode; the target working condition includes healthy working condition and damaged working condition.

[0051] Taking the healthy operating condition as an example, by using the modal vector Φ of the target structure under the healthy operating condition to perform modal superposition on the mass vector M, stiffness vector K, and damping vector D of the target structure under the healthy operating condition, the modal mass vector M with n modes of the target structure under the healthy operating condition can be obtained. m Modal stiffness vector K m and modal damping vector D m Among them: M m =Φ T MΦ, D m =Φ T DΦ, K m =Φ T KΦ. Where Φ T This is the transpose matrix of the modal vector Φ. Additionally, it represents the natural frequency vector of the target structure with n modes under healthy operating conditions. Damping vector of the target structure with nth mode under healthy operating conditions Modal impact vector of the target structure with n modes under healthy operating conditions in, For M m The inverse matrix, B o Let be the initial impact vector of the target structure under healthy operating conditions. The solution process for each variable can refer to existing techniques. The solution process for each variable of the target structure under damaged operating conditions can refer to the solution process for each variable under healthy operating conditions.

[0052] by Figure 1b Taking the target structure shown as an example, the mass vector M, stiffness vector K, and damping vector D are all 31×31 dimensional vectors. m K m and D m All are 10×10 dimensional diagonal vectors. Taking the total number of modes n as 10, then B... m It is a 10×1 dimensional column vector. C m The strain is determined by the displacement-strain transformation vector and modal vector Φ of the target structure under healthy conditions. The process for solving the comprehensive strain value of each mode of each structural element of the target structure under damaged conditions can refer to the process for solving the comprehensive strain value of each structural element of the target structure under healthy conditions.

[0053] In related technologies, the effect of damping is not considered when determining the damage index of structural units, resulting in a significant deviation from actual operating conditions. In this solution, if damping is not considered, The value of ζ is 1. i Let ω be the damping of the i-th mode of the target structure under the target operating condition. iLet be the natural frequency of the i-th mode of the target structure under the target operating condition. By incorporating damping factors when determining the damage index of structural elements in the target structure, the simulated finite element model can be made closer to the actual operating condition. This takes into account the influence of damping on the damage index, making the calculated damage index more accurate and avoiding false alarms. Furthermore, using the modal vectors under the target operating condition simplifies the number of degrees of freedom of the target structure, improving computational efficiency.

[0054] In one feasible implementation, the modal displacement-strain conversion vector is optionally determined based on the following formula:

[0055] C m =C q Φ;

[0056] Among them, C m Let C be the modal displacement-strain transformation vector of the target structure under the target working condition. q Φ is the displacement-strain transformation vector of the target structure under the target working condition, and Φ is the modal vector of the target structure under the target working condition;

[0057] Among them, C q =yq - ;

[0058] Among them, the Let y be the strain vector of the target structure under the target working condition. a Let x be the strain value of the a-th structural unit in the target structure, and let x be the strain value in the strain vector, which is obtained by measuring the strain using a strain sensor or a strain patch; x is the maximum number of rows in y.

[0059] Among them, the The q b Let z be the displacement of the b-th node in the target structure, and z be the maximum row number of q; q - Φ is the generalized inverse vector corresponding to the displacement vector of the target structure under the target working condition; Φ is obtained based on the ground vibration test corresponding to the target structure under the target working condition.

[0060] Among them, with Figure 1b Taking the target structure shown as an example, and taking the damage condition as an example, C q The modal displacement-strain transformation vector C of the target structure under damage conditions can be obtained by reducing the order of the modal vectors of the target structure under damage conditions, which is a 21×31 dimensional vector. m C m It is 21 × 10⁻⁶ dimensional. Where, C… qA strain vector, composed of displacement-strain conversion coefficients, is a shape function of an element and can be calculated from the strain and displacement vectors of the target structure under damage conditions. The strain vector of the target structure under damage conditions and the displacement vectors of each node corresponding to the structural element under damage conditions can be directly obtained using existing technologies. For example, strain gauges or strain sensors can be used to obtain the strain vector of the target structure under damage conditions during actual flight. (C) q Vectors link the displacement information of structural elements and nodes of the target structure under the target working condition; two nodes describe one structural element. q Multiplying a vector by a displacement vector reveals the strain value of a structural element. The generalized inverse of the displacement vector q can be found using methods for solving related generalized inverse vectors. The methods for solving the variables of the target structure under healthy conditions can be found using methods for solving the variables of the target structure under damaged conditions.

[0061] Therefore, by determining the displacement-strain transformation vector of the target structure under the target working condition through the strain vector and displacement vector corresponding to the target structure under the target working condition, and then using the modal vector to reduce the order of the displacement-strain transformation vector to determine the modal displacement-strain transformation vector of the target structure under the target working condition, the damage index of the target structure under the target working condition can be determined.

[0062] In one feasible implementation, optionally, the modal weighting coefficient vector of the target structure under the target operating condition is determined based on the following formula:

[0063] λ m =Φ T λΦ;

[0064] Where, λ m λ is the modal weighting coefficient vector of the target structure under the target operating condition, and Φ is the weighting coefficient vector of the target structure under the target operating condition. T This is the transpose of the modal vector of the target structure under the target operating condition;

[0065] in,

[0066] Among them, the Let λ be the weight coefficient of the r-th row and s-th column in the given λ, where u is the maximum number of rows and v is the maximum number of columns;

[0067] Wherein, the C′ qrs Let C be the displacement-strain transformation vector of the target structure under healthy operating conditions. q The displacement-strain conversion coefficient in the r-th row and s-th column; where,

[0068] Among them, with Figure 1b Taking the target structure shown as an example, λ and C q Each of the vectors is a 21×31 dimensional vector, and the non-zero weight coefficients in λ are determined by C. q The corresponding non-zero displacement-strain conversion coefficients in ' are weighted and determined. λ can be based on the displacement-strain conversion vector C of the target structure under healthy conditions. q The modal weighting coefficient vector λ of the target structure under the target condition is determined based on λ and the modal vector under the target condition. Φ is a 31×10-dimensional vector representing the modal vector of the target structure under the target condition, obtained through ground resonance tests under the target condition. m , λ m It is a diagonal vector representing the vector composed of the modal weight coefficients of each mode corresponding to each structural unit in the target structure under the target working condition.

[0069] Since the vibration of different structural units in the target structure is random, λ can be used to reduce the weighting coefficient of weak structural units in the target structure. For example, some structural units have low stiffness and large strain values ​​after being impacted. If no weighting coefficient is added, there will be a problem of poor sensitivity, and the damage index will be very high. However, in reality, the structural unit is not damaged.

[0070] Therefore, by adding a weighting coefficient to each structural unit in the target structure, the problem of random vibration can be avoided, the damage index of the structural unit calculated in the end can be more accurate, the accuracy of positioning can be improved, and false alarms can be avoided.

[0071] S130: Based on the damage index of each structural unit, generate a damage index histogram corresponding to the target structure.

[0072] In this embodiment of the invention, with Figure 1b Taking the target structure shown as an example, if the stiffness reduction rate of structural element S3 is 70%, the stiffness reduction rate of structural element S11 is 30%, and the stiffness reduction rate of structural element S18 is 50% under the damage condition, then the damage index of each structural element of the target structure under this damage condition is calculated using the damage index formula. Considering damping, the damage index histogram generated based on the damage index of each structural element in the target structure is shown below. Figure 1c As shown. Without considering damping, the damage index histogram generated based on the damage index of each structural unit in the target structure is shown below. Figure 1d As shown. Among them, Figure 1c and Figure 1d The horizontal axis represents the structural units of the target structure, and the vertical axis represents the damage index of each structural unit in the target structure under damage conditions.

[0073] Combination Figure 1c-1dIt can be seen that by taking damping factors into account when determining the damage index of each structural unit in the target structure, the working conditions of the simulated finite element model can be made closer to the actual working conditions, and the loss index determined in this way is more accurate, thus avoiding false alarms.

[0074] S140: Based on the damage index histogram, determine the structural units in the target structure that have damage.

[0075] The damage index histogram can visually identify damaged structural units within the target structure. For example, the relationship between the damage index of a particular structural unit and the damage indices of other structural units can be used to determine damaged structural units, or the relationship between the damage index of a particular structural unit and a preset damage index can be used to determine damaged structural units.

[0076] Specifically, such as Figure 1c As shown, considering damping, the damage indices of structural units S3, S11, and S18 are significantly higher than those of other structural units, indicating that structural units S3, S11, and S18 are damaged under this working condition.

[0077] In one feasible implementation, optionally, determining the damaged structural units in the target structure based on the damage index histogram includes: if the damage index of the target structural unit is higher than a preset damage index in the damage index histogram, then determining that the target structural unit is damaged.

[0078] The system can simultaneously display the preset damage index and the damage index of all structural units in the target structure in a damage index bar chart. If the loss index of a certain structural unit in the target structure is higher than the preset damage index, it indicates that the structural unit corresponding to that damage index is damaged.

[0079] Therefore, by determining that the target structural unit is damaged if the damage index of the target structural unit is higher than the preset damage index in the damage index histogram, it is possible to determine the damaged structural unit based on the damage index histogram and the preset damage index.

[0080] The technical solution provided by this invention determines a first parameter value for the healthy operating condition corresponding to a structural unit in a target structure, and a second parameter value for the damaged operating condition corresponding to the structural unit; determines the damage index of the structural unit based on the first and second parameter values; generates a damage index histogram corresponding to the target structure based on the damage index of each structural unit; and identifies the structural units in the target structure that have damage based on the damage index histogram. By implementing this solution, it is possible to quickly, reliably, and sensitively capture instantaneous dynamic impact responses during aircraft operation, thereby enabling high-precision and high-sensitivity detection of multiple potential defects and damages in the aircraft structure.

[0081] To more clearly illustrate the technical solution of the present invention, the technical solution provided in the embodiments of the present invention may include the following steps:

[0082] Step 1: Establish the damage index formula

[0083]

[0084] If the damage index determined by the strain value obtained by the strain sensor on a certain structural unit is significantly greater than the damage index determined by the strain value obtained by the strain sensor on other structural units, it indicates that there is damage at this location. These are quantities related to the target structure's inherent mode vector, structural stiffness vector, mass vector, and impact response strain vector. The formula also varies depending on whether damping is considered.

[0085] Step 2: In the damage index formula, the comprehensive strain value 2-norm of the target structure under the target working condition ||G ki When superimposing ||2, a weighting coefficient for the target structure under the target working condition is introduced. The definition of this weighting coefficient is as follows:

[0086]

[0087] Wherein, the C′ qrs Let C be the displacement-strain transformation vector of the target structure under healthy operating conditions. q The displacement-strain conversion coefficient in the r-th row and s-th column of '.

[0088] Step 3: Establish one planar truss structure under healthy operating conditions and two planar truss structures under damaged operating conditions. Each structural element has 3 degrees of freedom (DOF(X,Y,θ)). The planar truss structure is as follows: Figure 1b As shown in Table 1, two damage models are used to illustrate the problem.

[0089] Table 1. Description of Damage Models

[0090]

[0091]

[0092] Step 4: Extract the strain values ​​of the impact response of each structural unit in the target structure, substitute them into the parameters in Step 1, calculate the damage index, and try to determine whether the structural unit is damaged.

[0093] Step 5: By establishing a parameterized subroutine, calculate the damage index of a single structural unit. Call the subroutine to calculate the damage index of multiple structural units. The program considers both damped and undamped cases. For example... Figures 2a-2bAs shown, in damage condition one, the damage index of the damaged structural unit S3 is significantly higher than that of other structural units, and this effect is even more pronounced when damping is considered. Figure 2a and Figure 2b The horizontal axis represents the structural elements of the target structure, and the vertical axis represents the damage index of each structural element in the target structure under the damage condition.

[0094] like Figure 1c-1d As shown, in damage condition two, the damage indices of damaged structural units S3, S11, and S18 are significantly higher than those of other structural units, and this effect is even more pronounced when damping is considered. Figure 1c and Figure 1d The horizontal axis represents the structural unit of the target structure, and the vertical axis represents the damage index of each structural unit in the target structure under damage condition two.

[0095] Step 6: Obtain the strain value of the truss structure by attaching strain gauges or other methods to the beams. Under vibration and impact, transmit the strain value. Calculate the damage index using the program developed in Step 1 to finally locate the damaged area.

[0096] The technical solution provided by this invention is a structural health monitoring method based on strain 2-norm. It uses the derived damage index formula as the evaluation index, extracts the strain value of the impact response, establishes a subroutine, and calls the subroutine to accurately locate the positions of multiple damaged structural units in the target structure.

[0097] Figure 3 This is a schematic diagram of a structural health monitoring device provided in an embodiment of the present invention. The device can be configured in an electronic device used for structural health monitoring, such as... Figure 3 As shown, the device includes:

[0098] The parameter value determination module 310 is used to determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and to determine the second parameter value of the damage working condition corresponding to the structural unit.

[0099] The damage index determination module 320 is used to determine the damage index of the structural unit based on the first parameter value and the second parameter value;

[0100] The damage index histogram generation module 330 is used to generate a damage index histogram corresponding to the target structure based on the damage index of each structural unit.

[0101] The damaged structural unit determination module 340 is used to determine the structural units with damage in the target structure based on the damage index histogram.

[0102] Optionally, the damage index determination module 320 is specifically used to determine the damage index of the structural unit based on the following formula:

[0103]

[0104] Among them, DI k The damage index is the k-th structural unit in the target structure. The first parameter value of the k-th structural unit in the target structure; The second parameter value of the k-th structural unit in the target structure;

[0105] in,

[0106] Where i represents the i-th mode, and n represents the total number of modes of the target structure under healthy operating conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under healthy operating conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under healthy operating conditions. The comprehensive strain value of the k-th structural unit in the target structure under healthy operating conditions in the i-th mode;

[0107] in,

[0108] Wherein, l represents the total number of modes of the target structure under damage conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under damage conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under damage conditions. The comprehensive strain value of the k-th structural unit in the target structure under the damage condition is the i-th mode.

[0109] Optionally, the comprehensive strain value of the k-th structural unit in the target structure under the i-th mode under the target working condition is determined based on the following formula:

[0110]

[0111] Among them, G ki Let be the comprehensive strain value of the k-th structural unit in the target structure under the i-th mode of the target working condition. Let ζ be the i-th component of the modal impact vector of the target structure under the target working condition. i Let ω be the damping of the i-th mode of the target structure under the target operating condition. i Let be the natural frequency of the i-th mode of the target structure under the target operating condition. The element in the k-th row and i-th column of the modal displacement-strain transformation vector represents the modal strain of the k-th structural unit in the target structure under the target working condition in the i-th mode; the target working condition includes healthy working condition and damaged working condition.

[0112] Optionally, the modal displacement-strain conversion vector is determined based on the following formula:

[0113] C m =C q Φ;

[0114] Among them, C m Let C be the modal displacement-strain transformation vector of the target structure under the target working condition. q Φ is the displacement-strain transformation vector of the target structure under the target working condition, and Φ is the modal vector of the target structure under the target working condition;

[0115] Among them, C q =yq - ;

[0116] Among them, the Let y be the strain vector of the target structure under the target working condition. a Let x be the strain value of the a-th structural unit in the target structure, and let x be the strain value in the strain vector, which is obtained by measuring the strain using a strain sensor or a strain patch; x is the maximum number of rows in y.

[0117] Among them, the The q b Let z be the displacement of the b-th node in the target structure, and z be the maximum row number of q; q - Φ is the generalized inverse vector corresponding to the displacement vector of the target structure under the target working condition; Φ is obtained based on the ground vibration test corresponding to the target structure under the target working condition.

[0118] Optionally, the damaged structural unit determination module 340 is specifically used to determine that the target structural unit is damaged if the damage index of the target structural unit is higher than the preset damage index in the damage index histogram.

[0119] Optionally, the modal weighting coefficient vector of the target structure under the target operating condition is determined based on the following formula:

[0120] λ m =Φ T λΦ;

[0121] Where, λ m λ is the modal weighting coefficient vector of the target structure under the target operating condition, and Φ is the weighting coefficient vector of the target structure under the target operating condition. TThis is the transpose of the modal vector of the target structure under the target operating condition;

[0122] in,

[0123] Among them, the Let λ be the weight coefficient of the r-th row and s-th column in the given λ, where u is the maximum number of rows and v is the maximum number of columns;

[0124] Wherein, the C′ qrs Let C be the displacement-strain transformation vector of the target structure under healthy operating conditions. q The displacement-strain conversion coefficient in the r-th row and s-th column of '; where,

[0125] Optionally, the device further includes a finite element model construction module, used to construct a healthy finite element model corresponding to the target structure under a healthy condition and a damage finite element model corresponding to the target structure under a damage condition before determining the first parameter value of the healthy condition corresponding to the structural unit in the target structure and the second parameter value of the damage condition corresponding to the structural unit. Correspondingly, determining the first parameter value of the healthy condition corresponding to the structural unit in the target structure and determining the second parameter value of the damage condition corresponding to the structural unit includes: determining the first parameter value of the healthy condition corresponding to the structural unit in the target structure based on the healthy finite element model and determining the second parameter value of the damage condition corresponding to the structural unit based on the damage finite element model.

[0126] The apparatus provided in the above embodiments can execute the structural health monitoring method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0127] Figure 4 This is a schematic diagram of an electronic device structure provided in an embodiment of the present invention, such as... Figure 4 As shown, the device includes:

[0128] One or more processors 410, Figure 4 Taking a processor 410 as an example;

[0129] Memory 420;

[0130] The device may also include an input device 430 and an output device 440.

[0131] The processor 410, memory 420, input device 430, and output device 440 in the device can be connected via a bus or other means. Figure 4 Taking the example of a connection between China and Israel via a bus.

[0132] The memory 420, as a non-transitory computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to a structural health monitoring method in this embodiment of the invention. The processor 410 executes various functional applications and data processing of the computer device by running the software programs, instructions, and modules stored in the memory 420, thereby implementing a structural health monitoring method according to the above embodiment:

[0133] Determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and determine the second parameter value of the damaged working condition corresponding to the structural unit;

[0134] The damage index of the structural unit is determined based on the first parameter value and the second parameter value;

[0135] Based on the damage index of each structural unit, a damage index bar chart corresponding to the target structure is generated.

[0136] Based on the damage index histogram, structural units with damage in the target structure are identified.

[0137] The memory 420 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 420 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 420 may optionally include memory remotely located relative to the processor 410, and these remote memories can be connected to the terminal device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0138] Input device 430 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the computer device. Output device 440 may include display devices such as a display screen.

[0139] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a structural health monitoring method as provided in this invention, namely:

[0140] Determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and determine the second parameter value of the damaged working condition corresponding to the structural unit;

[0141] The damage index of the structural unit is determined based on the first parameter value and the second parameter value;

[0142] Based on the damage index of each structural unit, a damage index bar chart corresponding to the target structure is generated.

[0143] Based on the damage index histogram, structural units with damage in the target structure are identified.

[0144] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0145] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including—but not limited to—electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0146] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0147] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0148] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for monitoring structural health, characterized in that, include: Determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and determine the second parameter value of the damaged working condition corresponding to the structural unit; The damage index of the structural unit is determined based on the first parameter value and the second parameter value; Based on the damage index of each structural unit, a damage index bar chart corresponding to the target structure is generated. Based on the damage index histogram, structural units with damage in the target structure are identified. The step of determining the damage index of the structural unit based on the first parameter value and the second parameter value includes: The damage index of the structural unit is determined based on the following formula: ； in, The damage index is the k-th structural unit in the target structure. The first parameter value of the k-th structural unit in the target structure; The second parameter value of the k-th structural unit in the target structure; in, ; Where i represents the i-th mode, and n represents the total number of modes of the target structure under healthy operating conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under healthy operating conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under healthy operating conditions. The comprehensive strain value of the k-th structural unit in the target structure under healthy operating conditions in the i-th mode; in, ; Wherein, l represents the total number of modes of the target structure under damage conditions. The modal weight coefficient, representing the i-th mode of the k-th structural unit in the target structure under damage conditions, is the element in the k-th row and i-th column of the modal weight coefficient vector of the target structure under damage conditions. The comprehensive strain value of the k-th structural unit in the target structure under the damage condition is the i-th mode. The comprehensive strain value of the k-th structural unit in the target structure under the i-th mode in the target working condition is determined based on the following formula: ； in, Let be the comprehensive strain value of the k-th structural unit in the target structure under the i-th mode of the target working condition. Let i be the i-th component of the modal impact vector of the target structure under the target working condition. The damping of the i-th mode of the target structure under the target operating condition is given by [the damping term]. Let be the natural frequency of the i-th mode of the target structure under the target operating condition. The element in the k-th row and i-th column of the modal displacement-strain conversion vector represents the modal strain of the k-th structural unit in the target structure under the target working condition in the i-th mode. The target operating conditions include healthy operating conditions and damaged operating conditions.

2. The method according to claim 1, characterized in that, The modal displacement-strain conversion vector is determined based on the following formula: ； in, This represents the modal displacement-strain transformation vector of the target structure under the target working condition. This represents the displacement-strain transformation vector of the target structure under the target working condition. The modal vector of the target structure under the target operating conditions; in, ; Among them, the , is the strain vector of the target structure under the target working condition, the Let x be the strain value of the a-th structural unit in the target structure, and let x be the strain value in the strain vector, which is obtained by measuring the strain using a strain sensor or a strain patch; x is the maximum number of rows in y. Among them, the The Let z be the displacement of the b-th node in the target structure, and z be the maximum number of rows in q; This is the generalized inverse vector corresponding to the displacement vector of the target structure under the target working condition; The This information was obtained based on ground vibration tests conducted on the target structure under the target operating conditions.

3. The method according to claim 2, characterized in that, The modal weighting coefficient vector of the target structure under the target operating condition is determined based on the following formula: ； in, This refers to the modal weighting coefficient vector of the target structure under the target operating conditions. This represents the weighting coefficient vector of the target structure under the target operating conditions. This is the transpose of the modal vector of the target structure under the target operating condition; in, ; Among them, the , for the The weight coefficients in the r-th row and s-th column of the table, where u is the maximum number of rows and v is the maximum number of columns; Among them, the The displacement-strain transformation vector of the target structure under healthy operating conditions. The displacement-strain conversion coefficient in the r-th row and s-th column; where, .

4. The method according to claim 1, characterized in that, Based on the damage index histogram, structural units with damage in the target structure are identified, including: In the damage index histogram, if the damage index of the target structural unit is higher than the preset damage index, then the target structural unit is determined to be damaged.

5. The method according to claim 1, characterized in that, Before determining the first parameter value of the healthy operating condition corresponding to the structural unit in the target structure, and before determining the second parameter value of the damaged operating condition corresponding to the structural unit, the method further includes: Construct a healthy finite element model corresponding to the target structure under healthy operating conditions, and construct a damage finite element model corresponding to the target structure under damaged operating conditions; Accordingly, determining the first parameter value of the healthy operating condition corresponding to the structural unit in the target structure, and determining the second parameter value of the damaged operating condition corresponding to the structural unit, including: Based on the health finite element model, the first parameter value of the health condition corresponding to the structural unit in the target structure is determined, and based on the damage finite element model, the second parameter value of the damage condition corresponding to the structural unit is determined.

6. A structural health monitoring device, employing the structural health monitoring method of claim 1, characterized in that, include: The parameter value determination module is used to determine the first parameter value of the healthy working condition corresponding to the structural unit in the target structure, and to determine the second parameter value of the damage working condition corresponding to the structural unit. The damage index determination module is used to determine the damage index of the structural unit based on the first parameter value and the second parameter value; The damage index histogram generation module is used to generate a damage index histogram corresponding to the target structure based on the damage index of each structural unit. The damaged structural unit determination module is used to determine the structural units with damage in the target structure based on the damage index histogram.

7. An electronic device, characterized in that, include: One or more processors; Storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-5.

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