Internal load calculation device and internal load calculation method

Abstract

This invention provides an internal load calculation apparatus and an internal load calculation method. The internal load calculation apparatus includes: a storage unit that stores analytical results of calculating the internal load when the object component is in a healthy state; and a derivation unit that takes at least one of the multiple units constituting the object component as object units, and derives the distribution of the internal load of the object component when the object unit is damaged, based on the distribution of the internal load of the object component when an external load is applied to the object unit and the analytical results stored in the storage unit.

Description

Technical Field

[0001] This invention relates to an internal load calculation device and a method for calculating internal loads. Background Technology

[0002] In order to perform strength analysis of the components that make up an aircraft, the finite element method and the like are sometimes used (for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. WO2018 / 061280 Summary of the Invention

[0006] Technical issues

[0007] In order to derive the internal load of an object component relative to external loads, a computationally intensive process must be performed. There is a desire to develop a technique that can reduce the computational load involved in deriving internal loads.

[0008] In view of such problems, the present invention aims, in particular, to provide an internal load calculation device and an internal load calculation method that can reduce the computational load related to the derivation of internal loads in strength analysis when damage has occurred to the object component.

[0009] Technical Solution

[0010] To address the aforementioned issues, the internal load calculation apparatus of the present invention comprises: a storage unit that stores analytical results of calculating the internal load when the object component is in a healthy state; and a derivation unit that takes at least one of the plurality of units constituting the object component as object units, and derives the distribution of the internal load of the object component when the object unit is damaged, based on the distribution of the internal load of the object component when an external load is applied to the object unit and the analytical results stored in the storage unit.

[0011] In addition, the internal load calculation method of the present invention may include the following steps: taking at least one or more of the multiple units constituting the object component as the object unit, and deriving the distribution of the internal load of the object component under the condition that the object unit is damaged, based on the distribution of the internal load of the object component when the object unit is subjected to an external load and the analytical result of the internal load when the object component is in good condition. Attached Figure Description

[0012] Figure 1 This is a block diagram showing the internal load calculation device.

[0013] Figure 2 This is a schematic diagram showing the object components.

[0014] Figure 3 This is a schematic diagram showing the first result of the pre-analysis.

[0015] Figure 4 This is a schematic diagram showing the second result of the prior analysis.

[0016] Figure 5 This is a flowchart illustrating the process of deriving internal loads.

[0017] Figure 6 It is a graph summarizing the measurement results based on prior analysis.

[0018] Figure 7 The first figure shows a variation example.

[0019] Figure 8 The second figure shows a variation example.

[0020] Figure 9 The third figure shows a variation.

[0021] Figure 10 The fourth figure shows a variation.

[0022] Symbol Explanation

[0023] 100 Internal Load Calculation Device

[0024] 102 Damage Detection Unit

[0025] 104 Export Department

[0026] 200 object components

[0027] Unit 204a

[0028] 204b Object Unit Detailed Implementation

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in these embodiments are merely examples to facilitate understanding of the invention and are not intended to limit the invention unless specifically indicated. It should be noted that in this specification and the accompanying drawings, elements having substantially the same function or structure are labeled with the same symbols, and repeated descriptions are omitted. Furthermore, elements not directly related to the present invention are omitted from the illustrations.

[0030] As described above, in order to derive the internal load of an object component relative to external loads, computationally intensive processing must be performed. In this embodiment, the computational load related to the derivation of internal loads is reduced. More specifically, the computational load related to the derivation of internal loads of the object component in the event of damage to the object component is reduced.

[0031] Figure 1 This is a block diagram showing the internal load calculation device 100. (As shown) Figure 1 As shown, the internal load calculation device 100 is configured to include a damage detection unit 102, an output unit 104, and a storage unit 106. The internal load calculation device 100 is a personal computer equipped with a semiconductor integrated circuit. By executing a program, it functions as the damage detection unit 102 and the output unit 104. This semiconductor integrated circuit includes, for example, a central processing unit (CPU), a ROM storing programs, and RAM serving as a working area. Furthermore, the storage unit 106 is, for example, a hard disk drive and / or flash memory, and includes non-volatile storage elements. The storage unit 106 can store the analysis results of the target component 200 exported using the pre-analysis device 300.

[0032] In addition, a damage sensor 202 and a pre-analysis device 300 are connected to the internal load calculation device 100. The damage sensor 202 can detect damage to the object component 200 that is the object from which the internal load is derived.

[0033] Damage sensor 202 is a device that detects physical quantities of an object component constituting an aircraft during flight, for example. The physical quantity detected by damage sensor 202 is set to a desired physical quantity that changes when damage occurs to the object component. Typical and easily detectable physical quantities that change when damage occurs to the object component include deformation, vibration, and acceleration of the object component. Therefore, damage sensor 202 may also detect at least one of deformation, vibration, and acceleration of the object component.

[0034] The pre-analysis device 300 pre-analyzes the target component 200 and calculates the internal load of the target component 200 in its healthy state. Then, the analysis result of the target component 200 is stored in the storage unit 106. That is, when the internal load is calculated using the internal load calculation device 100, only the analysis result of the target component 200 pre-stored in the storage unit 106 needs to be retrieved.

[0035] Figure 2 This is a schematic diagram showing the object component 200. Figure 2 In the state shown, object component 200 is in a healthy state without any damage. For example... Figure 2As shown, the object component 200 is composed of a plurality of units 204a (here, thirty-six units 204a). It should be noted that, for ease of explanation, in this embodiment, the unit 204a is referred to as a membrane unit.

[0036] In this embodiment, an example is given of the case where the internal load of the object component 200 is derived when the object unit 204b in the plurality of units 204a is damaged.

[0037] Figure 3 This is a schematic diagram showing the first result of the pre-analysis. Additionally, Figure 4 This is a schematic diagram illustrating the second result of the prior analysis. It should be noted that various well-known methods, such as the finite element method, can be used in the prior analysis.

[0038] First, as a preliminary analysis, such as Figure 2 and Figure 3 As shown in (a), the pre-analysis device 300 determines the internal load of the object component 200 in its healthy state. In this embodiment, the distribution of the internal load of the object component 200 is determined when a 100N traction load is applied to each node of the object component 200 along the Y-axis. Here, as... Figure 2 As shown, at one end of the fixed object component 200, a traction load along the Y-axis is applied to each node located at the end opposite to the fixed side. It should be noted that... Figure 3 The values ​​in each cell represent the Y-axis component of the internal load of each unit 204a (or object unit 204b).

[0039] In addition, such as Figure 3 As shown in (b), the pre-analysis device 300 applies a hypothetical load to simulate the situation where damage occurs in the object unit 204b. Specifically, it determines the distribution of the internal load of the object component 200 when a load of 100N is applied to nodes 1 and 4 of the object unit 204b in opposite directions along the Y-axis.

[0040] In addition, such as Figure 3 As shown in (c), the pre-analysis device 300 determines the distribution of the internal load of the object component 200 when a load of 100N is applied to nodes 2 and 3 of the object unit 204b in opposite directions along the Y-axis.

[0041] In addition, such as Figure 3 As shown in (d), the pre-analysis device 300 determines the distribution of the internal load of the object component 200 when a load of 100N is applied to nodes 1 and 2 of the object unit 204b in opposite directions along the X-axis.

[0042] In addition, such as Figure 3 As shown in (e), the pre-analysis device 300 determines the distribution of the internal load of the object component 200 when a load of 100N is applied to nodes 3 and 4 of the object unit 204b in opposite directions along the X-axis.

[0043] In addition, such as Figure 3 As shown in (f), the pre-analysis device 300 determines the distribution of internal loads in the object component 200 when loads are applied to nodes 1 to 4. Specifically, the pre-analysis device 300 determines the distribution of internal loads in the object component 200 when loads of 100N are applied to nodes 1 and 2, and nodes 3 and 4 of the object element 204b respectively, in the opposite direction along the X-axis, and when loads of 100N are applied to nodes 1 and 4, and nodes 2 and 3 respectively, in the opposite direction along the Y-axis.

[0044] Next, as Figure 4 As shown in (a), the pre-analysis device 300 in Figure 3 The results of the prior analysis shown indicate that the load on the object unit 204b supported at nodes 1 to 4 is determined when each node of the object component 200 in a healthy state is subjected to a traction load of 100N along the Y-axis.

[0045] In addition, such as Figure 4 As shown in (b), the pre-analysis device 300 in Figure 3 The results of the prior analysis shown indicate the load on the object element 204b supported at nodes 1 to 4 when a load of 100N is applied to nodes 1 and 4 of the object element 204b to pull in opposite directions along the Y-axis.

[0046] In addition, such as Figure 4 As shown in (c), the pre-analysis device 300 in Figure 3 The results of the prior analysis shown indicate that the load on the object element 204b supported at nodes 1 to 4 is determined when a load of 100N is applied to nodes 2 and 3 of the object element 204b in opposite directions along the Y-axis.

[0047] In addition, such as Figure 4 As shown in (d), the pre-analysis device 300 in Figure 3 The results of the prior analysis shown show that the load on the object element 204b supported at nodes 1 to 4 is determined when a load of 100N is applied to nodes 1 and 2 of the object element 204b to pull in opposite directions along the X-axis.

[0048] In addition, such as Figure 4 As shown in (e), the pre-analysis device 300 in Figure 3The results of the prior analysis shown indicate that the load on the object element 204b supported at nodes 1 to 4 is determined when a load of 100N is applied to nodes 3 and 4 of the object element 204b to pull in opposite directions along the X-axis.

[0049] In addition, such as Figure 4 As shown in (f), the pre-analysis device 300 in Figure 3 The results of the prior analysis shown indicate that the loads on the object unit 204b supported by nodes 1 to 4 are determined when loads are applied to nodes 1 to 4. Specifically, the prior analysis device 300 determines the loads on the object unit 204b supported by nodes 1 to 4 when a load of 100N is applied to nodes 1 and 2, and nodes 3 and 4 respectively, in opposite directions along the X-axis, and when a load of 100N is applied to nodes 1 and 4, and nodes 2 and 3 respectively, in opposite directions along the Y-axis.

[0050] In this embodiment, although it is shown that the target unit 204b is subjected to Figure 3 and Figure 4 In the case of prior analysis, however, in practice, prior analysis only needs to be performed on all units 204a that may be damaged among all units constituting the object component 200. Units that may be damaged are, for example, exposed parts in an aircraft. Alternatively, prior analysis can be performed on all units 204a constituting the object component 200.

[0051] Furthermore, the pre-analysis device 300 stores the pre-analysis results in the storage unit 106 for each unit 204a. Figure 5 This is a flowchart illustrating the process of deriving internal loads.

[0052] The damage detection unit 102 determines whether damage has occurred in any unit 204a constituting the object component 200 based on the detection result of the damage sensor 202 (S101). As a result, if damage to the object component 200 is detected by the damage detection unit 102 (S101 yes), the damage detection unit 102 detects information such as the location and size of the damage in the object component 200 (S103). Here, for ease of explanation, it is assumed that damage is detected at one location in the object unit 204b by the damage detection unit 102.

[0053] The export unit 104 obtains the pre-analysis results stored in the storage unit 106 (S105). Figure 6 This is a diagram summarizing the pre-analysis results of object unit 204b. In this embodiment, the acquisition... Figure 6 The result of the prior analysis is shown in (a).

[0054] The extraction unit 104 extracts a predetermined amount of information from the load information of the units 204a surrounding the object unit 204b in the prior analysis results of the object unit 204b (S107). Specifically, for example, when a total of five components are extracted, at most three components are selected from the Fx components of nodes 1 to 4, and at most three components are selected from the Fy components of nodes 1 to 4. That is, two components can be selected from the Fx components of nodes 1 to 4 and three components can be selected from the Fy components of nodes 1 to 4, or three components can be selected from the Fx components of nodes 1 to 4 and two components can be selected from the Fy components of nodes 1 to 4. It should be noted that although the predetermined number is set to five in this embodiment, as will be described later, the number of components to be extracted varies depending on the number of damaged units, the type of units, etc. Here, as Figure 6 As shown in (b), for (2) to (6), the Fx components of nodes 1 to 3 and the Fy components of nodes 1 to 2 are extracted and represented by a 5×5 matrix.

[0055] The following is a combination Figure 6 The external loads (2) to (6) of (a) reproduce the same state as the damaged object element 204b. Specifically, under the desired load conditions (here, Figure 6 Under the load (1) supported by the object unit (a), the combination of external loads (2) to (6) is derived, which is a load that can make only the same load as the load supported by the object unit 204b act on the peripheral unit of the object unit 204b.

[0056] Furthermore, the derivation unit 104 calculates the inverse matrix of the aforementioned 5×5 matrix (S109). Here, the inverse matrix is ​​calculated as shown in the following mathematical formula (1).

[0057]

Mathematical Formula 1

[0058]

[0059] Next, the derivation unit 104 extracts the information of the load supported by the object unit 204b in the prior analysis result of the object unit 204b (S111). Specifically, in the load supported by the object unit 204b in the healthy state, the Fx components of nodes 1 to 3 and the Fy components of nodes 1 to 2 are extracted for (1) respectively and represented by a 1×5 matrix.

[0060] Furthermore, as shown in the following mathematical formula (2), the product of the above inverse matrix and the above 1×5 matrix is ​​obtained (S113). The right side of the following mathematical formula (2) shows the magnitude (coefficient) of the nodal loads necessary to derive (simulate) the damage state.

[0061]

Mathematical Formula 2

[0062]

[0063] Furthermore, the derivation unit 104 compares the internal load under external load conditions with the internal load under healthy conditions obtained in the prior analysis using the coefficients derived from the above mathematical formula (2). Figure 3 The internal loads of the object component 200 under the damaged state of the object unit 204b are derived (S115). When adding, the value obtained from the above mathematical formula (2) is used as a coefficient.

[0064] Specifically, as shown in the following mathematical formula (3), the internal load in the healthy state is derived ( Figure 3 (a) plus Figure 3 The value obtained by multiplying the internal load of (b) by the value (coefficient) in the first row on the right side of the above mathematical formula (2) is: Figure 3 The value obtained by multiplying the internal load of (c) by the value (coefficient) in the second row on the right side of the above mathematical formula (2) is: Figure 3 The value obtained by multiplying the internal load of (d) by the value (coefficient) in the third row on the right side of the above mathematical formula (2) is: Figure 3 The value obtained by multiplying the internal load of (e) by the value (coefficient) in the fourth row on the right side of the above mathematical formula (2), and Figure 3 The value is obtained by multiplying the internal load of (f) by the value (coefficient) in the fifth row on the right side of the above mathematical formula (2).

[0065]

Mathematical Expression 3

[0066]

[0067] The internal load distribution derived from the above mathematical formula (3) is equivalent to the internal load of the object component 200 when the object unit 204b is damaged.

[0068] As described above, in this embodiment, the distribution of internal loads when the object component 200 is in a healthy state is analyzed and stored in advance. In the event that any unit in unit 204a is actually damaged, the internal loads when external loads are applied using coefficients derived from the damaged location are added to the internal distributions when the object component 200 is in a healthy state, thereby deriving the internal loads of the object component 200 in the damaged state of object unit 204b.

[0069] Since the internal load of the object component 200 under the damaged state of object element 204b can be derived as described above, complex calculations such as the finite element method are unnecessary after the damage to element 204a is generated. This reduces the computational burden related to deriving the internal load. Furthermore, when the internal load of the object component 200 under the damaged state is derived using the method of this embodiment, the value is almost identical to that derived entirely using the finite element method without using the above method.

[0070] While preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is by no means limited to these embodiments. Various modifications and alterations will be conceived by those skilled in the art within the scope of the claims, and these naturally fall within the technical scope of the present invention.

[0071] For example, while the above embodiment illustrates a case where only one object element 204b is damaged, the invention is not limited thereto. As described above, in the case of damage to a single object element 204b, the internal load can be derived by analyzing a 5×5 matrix. Even when the damage spans multiple elements 204a, although the matrix dimension increases, the internal load can still be derived in the same manner as described above.

[0072] It should be noted that if it is a membrane element, the dimension of the matrix to be analyzed (i.e., the degree of freedom of the load) can be expressed using a mathematical formula such as "number of damaged elements × 5 - number of edges shared by the damaged elements".

[0073] Figure 7 This is the first diagram showing a variation. For example, in Figure 7 In case (a), two object units 204b are damaged. Since the number of edges shared by unit 204b is 1, the total number becomes 2 × 5 - 1 = 9. Furthermore, in Figure 7 In case (b), two object units 204b are damaged. Since the number of edges shared by object units 204b is 0, the total number of damaged edges is 2 × 5 - 0 = 10. Additionally, in Figure 7 In case (c), there are four damaged object units 204b. Since the number of edges that object units 204b share is 4, the total number of damaged objects is 4 × 5 - 4 = 16.

[0074] Figure 8 This is the second figure showing a variation. For example... Figure 8 As shown, when the damaged object element 204b is located at a corner of the object component 200 (hereinafter also referred to as a corner element), although nodes a, b, and d have load transfer with other elements, node c, located at the corner of the object component 200, does not generate load transfer with other elements. Therefore, in the case of a corner element, the load degree of freedom becomes... Figure 8 (b) Figure 8 The translational bidirectional equilibrium shown in (c) and Figure 8 The rotational unidirectional balance shown in (d) has a total of 3 degrees of freedom.

[0075] For the corner elements, the 5×5 matrix can be analyzed in the same way as in the case of damage to object element 204b. In this case, simply setting the Fx and Fy components of the load at node c to 0N is sufficient. By doing so, it is not necessary to specially modify the processing only for the corner elements, thus preventing the program from becoming too complex.

[0076] Furthermore, although the above embodiment shows the case where unit 204a is a membrane unit, this embodiment is not limited to this. Figure 9 The third figure illustrates a modified example. For example, the invention can also be applied to... Figure 9 The plate element shown has both in-plane and out-of-plane rigidity. In the case of a plate element, the degree of freedom of the load becomes... Figure 9 In-plane stretching as shown in (a) (four modes), Figure 9 Out-of-plane shearing, bending (eight modes) as shown in (b), and Figure 9 As shown in (c), there are a total of 14 degrees of freedom, including in-plane shear and torsion.

[0077] Figure 10 Figure 4 shows a modified example. For example, the invention can also be applied to... Figure 10 The bar element shown has axial force, bending, and torsional rigidity. In the case of the bar element, the degree of freedom of the load becomes... Figure 10 Axial force, torsion, and as shown in (a) Figure 10 As shown in (b), there are a total of 6 degrees of freedom, including shearing and bending (four modes).

[0078] Industrial availability

[0079] This invention can be used in internal load calculation devices.

Claims

1. An internal load calculation device, characterized in that, have: The storage unit stores the results of prior analysis of the internal loads when the object component is in a healthy state; and The derivation unit takes at least one of the multiple units constituting the object component as the object unit, and derives the distribution of the internal load of the object component under the condition that the object unit is damaged, based on the distribution of the internal load of the object component when an external load is applied to the object unit and the result of the prior analysis stored in the storage unit. The results of the prior analysis include: The first distribution of the internal load of the object component under the condition that the object unit is undamaged and a predetermined load is applied to the object component; and the first load of the object unit at the node support; and The second distribution of the internal load of the object component under the condition that the object unit is undamaged and a predetermined load is applied to the node, and the second load of the object unit supported at the node. The derivation unit is configured to extract from the results of the prior analysis a predetermined number of first loads on the object unit at the node support when the object unit is undamaged and a predetermined load is applied to the object component, and second loads on the object unit at the node support when the object unit is undamaged and a predetermined load is applied to the node. The product of the inverse matrix of the loads acting on the peripheral units of the object unit (obtained by adding the extracted second loads and the external loads) and the extracted first load matrix is ​​used as a coefficient for the node loads necessary to derive the damage state. Using the coefficients, the first distribution of the internal load of the object component when a predetermined load is applied to the object component without damage to the object unit, and the second distribution of the internal load of the object component when a predetermined load is applied to the node without damage to the object unit, the product of the second distribution and the coefficients is added to the matrix of the first distribution, thereby deriving the distribution of the internal load of the object component when the object unit is damaged.

2. A method for calculating internal loads, characterized in that, The internal load calculation method includes the following steps: taking at least one of the multiple units constituting the object component as the object unit, and deriving the distribution of the internal load of the object component under the condition that the object unit is subjected to an external load, and the result of a prior analysis of the internal load when the object component is in a healthy state. The results of the prior analysis include: The first distribution of the internal load of the object component under the condition that the object unit is undamaged and a predetermined load is applied to the object component; and the first load of the object unit at the node support; and The second distribution of the internal load of the object component under the condition that the object unit is undamaged and a predetermined load is applied to the node, and the second load of the object unit supported at the node. In this step, a predetermined number of loads are extracted from the results of the prior analysis. These loads represent the first load on the object unit at the node support when the object unit is undamaged and a predetermined load is applied to the object component. The second load on the object unit at the node support when the object unit is undamaged and a predetermined load is applied to the node is then calculated. The product of the inverse matrix of the loads acting on the peripheral units of the object unit (obtained by adding the extracted second loads and the external loads) and the extracted first load matrix is ​​used as the coefficient for the node loads necessary to derive the damage state. Using the coefficients, the first distribution of the internal load of the object component when a predetermined load is applied to the object component without damage to the object unit, and the second distribution of the internal load of the object component when a predetermined load is applied to the node without damage to the object unit, the product of the second distribution and the coefficients is added to the matrix of the first distribution, thereby deriving the distribution of the internal load of the object component when the object unit is damaged.

Images