High load bearing ear tab joint at any angle and design method

Abstract

This invention belongs to the field of aircraft structural design, and specifically relates to a high-load-bearing lug connector with an arbitrary angle and its design method. The lug connector includes: a lug, a base, and bushings; the base includes a transverse base and a longitudinal base; the lug is disposed above the base; two bushings are installed in the lug holes; the lug axis forms an arbitrary angle θ with the longitudinal base; the transverse and longitudinal bases intersect each other in a "+" shape and are distributed on both sides of the lug. The base plates of the longitudinal and transverse bases are designed with stepped thicknesses of different thicknesses. Compared with conventional lug connectors, the connector structure designed using this invention differs in that the lug of the connector is not affected by the direction of the connecting base, resulting in high design flexibility and not affecting the load-bearing performance of the connector.

Description

Technical Field

[0001] This invention belongs to the field of aircraft structural design, specifically relating to a high load-bearing lug joint with an arbitrary angle and its design method. Background Technology

[0002] Generally, the lug joints connecting to the aircraft fuselage structure, especially high-load-bearing joints, have lugs arranged in the same direction as the supporting structure behind the joint. For example, joints installed on transverse frame strips generally have lugs aligned with the frame plane; similarly, joints installed on longitudinal members such as beams have lugs aligned with the beam web. However, in some cases, the joint load direction cannot meet the above requirements due to spatial angles. If conventional lug design is used, it may not be possible to utilize the existing longitudinal and transverse structural members of the fuselage for reinforcement and support. An additional joint support structure needs to be designed on the fuselage, which will result in additional structural weight. Furthermore, the joint load needs to be transferred to the existing longitudinal and transverse members of the fuselage structure through the newly added joint support structure. The force transmission path is not direct, the force transmission path design is complex and indirect, and the assembly process is poor. Summary of the Invention

[0003] The purpose of this invention is to provide a high load-bearing lug connector and method with an arbitrary angled placement, so as to solve at least one problem of the conventional lug connector in the above-mentioned background art.

[0004] The technical solution of the present invention is as follows: On the one hand, the present invention proposes a high load-bearing lug connector with an arbitrary angle of tilt, comprising: Ear piece, the ear piece being disposed above the base; A base, comprising a horizontal base and a vertical base; The ear plate axis is at any angle to the longitudinal base. θ angle; The horizontal and vertical bases intersect each other in a cross shape and are distributed on both sides of the ear piece.

[0005] Furthermore, the ear connector also includes bushings, of which there are two bushings, which are respectively installed in the ear holes at both ends of the ear piece.

[0006] Furthermore, the cross-sectional shape of the horizontal base and the vertical base is U-shaped or L-shaped.

[0007] Furthermore, the horizontal base and the vertical base mounting plate adopt a stepped variable thickness design.

[0008] Furthermore, the transverse base and longitudinal base are each connected to the transverse and longitudinal components of the body structure by four fasteners.

[0009] Furthermore, the fasteners are arranged in two concentric rings, inner and outer, with the inner ring fasteners on both sides of the ear plate axis positioned at a distance from the ear hole axis. a , a On the two straight lines of ′, the outer ring fasteners are respectively arranged at a distance of ′ from the axis of the ear hole. b , b On the two straight lines of ′.

[0010] Furthermore, the intersection of the fastener arrangement lines on the transverse base and the longitudinal base O "Located within the center plane of the ear piece thickness."

[0011] Furthermore, a light-reducing hole may be designed between the ear piece and the base as needed.

[0012] In another aspect, the present invention also proposes a design method for a high-load-bearing lug connector with an arbitrary angle as described above, comprising the following steps: Step 1: Coordinate the position of the connector lugs; Step 2: Select loads and confirm load direction; Step 3: Design of ear plate and bushing parameters; Step 4: Determine the initial dimensions of the base connection fasteners based on the load. Step 5: Base parameter design; Step Six: Detailed Design; Step 7: Verify whether the margin meets the requirements.

[0013] Furthermore, in step two, the load F Includes tensile load F 1 and compressive load F 2.

[0014] Furthermore, in step four, the load estimate required to determine the size of the individual fasteners connecting the base is as follows: Tensile load according to, ; Shear load according to, ; in β The load borne by the high load-bearing lug joint F The angle between the base and the bottom surface.

[0015] Furthermore, in step five, the base parameter design includes the thickness of the base fastener base plate, the height of the base flange, and the transition radius between the flange and the ear piece connector. r 1. r 2, the aforementioned r 1. r 2 should be as large as possible; Furthermore, in step seven, the verification margin includes the tensile and shear strength verification of the base fasteners, the compressive strength verification of the nail holes, and the strength verification of the lugs.

[0016] Compared to conventional lug connectors, the high-load-bearing connector of this invention is unaffected by the orientation of the machine support structure connected to the connector base. It can be reinforced based on the existing layout of the machine structure, offering high design flexibility and allowing for flexible connector design without compromising load-bearing performance. The machine structure connected to the connector requires no additional reinforcement, resulting in high structural utilization, simplified machine support structure, fewer parts, and reduced weight. Attached Figure Description

[0017] Figure 1 A schematic diagram of a high-load-bearing lug joint with an arbitrary angle of inclination; Figure 2 A front view of the geometric dimensions of a high-load-bearing lug joint positioned at an arbitrary angle. Figure 3 for Figure 2 View from direction A; Figure 4 Design process for high load-bearing lug connectors placed at any angle; Wherein: 11-ear piece, 12-base, 12a-lateral base, 12b-vertical base, 13-shoulder. a , a ′- Distance between the inner ring fasteners on both sides of the ear hole axis and the ear hole axis. b , b ′- Distance between the outer ring fasteners on both sides of the ear hole axis and the ear hole axis. F - The joint bears the load ( F 1 represents the tensile load. F 2 represents the compressive load. β -load F Deflection angle θ - Earplate angled O 1-Center of the ear canal, O′ -load F The intersection with the bottom surface of base 12 O″ - The intersection of the longitudinal and transverse fastener arrangement lines is also the center of the ear hole. O 1. Projection on the mounting surface of the base. h - Height of the ear hole from the bottom surface of the base (12mm) L - Earplate thickness. Detailed Implementation

[0018] To better understand the function and purpose of the present invention, and not to be regarded as a limiting solution, the following detailed description of the embodiments of the present invention is given based on the accompanying drawings.

[0019] In the accompanying drawings, the same symbols represent the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without further creative effort are all within the protection scope of the present invention. A detailed description is provided below with reference to the accompanying drawings.

[0020] Figure 1 The diagram shows an axonometric view of a high-load-bearing lug joint with an arbitrary angle, illustrating the main structural shape and component composition of the joint. Figure 2 A front view of the geometric dimensions of a high-load-bearing lug joint positioned at an arbitrary angle. Figure 3 It shows Figure 2 The A-direction view further illustrates the load. F angular relationship; Figure 4 The design flowchart for the ear-shaped connector is shown.

[0021] Specifically, such as Figure 1 As shown, an axonometric schematic diagram of a high load-bearing lug connector with an arbitrary angle is shown, mainly illustrating the main structure of the connector, which includes a lug 11, a base 12, and bushings 13. The lug 11 is positioned above the base 12, which includes a transverse base 12a and a longitudinal base 12b. Two bushings 13 are pressed into the lug holes at both ends of the lug 11.

[0022] Figure 2 This is a front view of the geometry of a high-load-bearing lug joint positioned at an arbitrary angle. Figure 3 for Figure 2 View A shows the key dimensional design relationships of the connector front view.

[0023] Specifically, by Figure 2 It can be seen that the ear piece 11 is not parallel to the transverse base 12a and the longitudinal base 12b arranged laterally and longitudinally, but is at an arbitrary angle to the longitudinal base 12b. θ Angle design: The transverse base 12a and longitudinal base 12b intersect at 90° to form a cross shape and are distributed on both sides of the ear piece 11. To improve the support rigidity of the base, the cross-sectional shape of the transverse base 12a and longitudinal base 12b is designed to be U-shaped or L-shaped, and each base has a mounting hole. The transverse base 12a and longitudinal base 12b are connected to the transverse and longitudinal components of the body structure respectively by four fasteners on the inner and outer rings. The inner ring fasteners on both sides of the ear piece 11 axis are respectively arranged at a distance of [missing information - likely a distance from the ear hole axis]. a , a On the two straight lines of ′, the outer ring fasteners are respectively arranged at a distance of ′ from the axis of the ear hole. b , bOn the two straight lines of ′; considering that the distance between the inner and outer ring fasteners and the ear hole axis is not consistent, the load distribution after the structure is connected is uneven. When the structure is subjected to out-of-plane tensile load, the inner ring fastener bears a larger load, while the in-plane shear load is evenly distributed and borne by all fasteners. Therefore, the transverse base 12a and the longitudinal base 12b adopt a stepped variable thickness design. The thickness of the base plate installed with the four inner ring fasteners is thicker than that of the base plate installed with the four outer ring fasteners, thereby improving the structural rigidity of the inner ring fastener connection and making it more conducive to the inner ring fastener bearing.

[0024] The present invention also provides a design method for a high load-bearing lug connector with an arbitrary angle of inclination, for designing the high load-bearing lug connector as described above, comprising: Step 1: Coordinate the position of the connector lugs; Step 2: Select loads and confirm load direction; Step 3: Design of ear plate and bushing parameters; Step 4: Determine the initial dimensions of the base connection fasteners based on the load. Step 5: Base parameter design; Step Six: Detailed Design; Step 7: Verify whether the margin meets the requirements.

[0025] The design method for a high-load-bearing lug connector with arbitrary angled placement according to the present invention firstly involves coordinating the position of the connector lug holes in step one. The load is transmitted to the body structure through the connector, and ultimately transmitted through the transverse and longitudinal components of the body structure. For example... Figure 3 As shown, the ear piece 11 and the load are displayed more clearly. F The relationship between directions O "It is the center of the ear canal" O 1. The projection point on the bottom surface of base 12, load F Through the center of the ear hole O The intersection of 1 and the bottom surface of base 12 is O′ , load F The angle between the base and the bottom surface of the base 12 is ∠ O 1 O ′ O "The bottom surface of base 12 refers to the lowest surface of base 12 that is in contact with the machine body. Adjusting the position of connector lug 11 is to obtain the ideal load as much as possible." F Direction. For example... Figure 2 When adjusting, it should be done from the direction of the ear axis ( x (towards) and perpendicular to the ear plate direction ( y Consider two directions: adjustment y A favorable load can be obtained by adjusting the position. F skew angle β From the perspective of fastener load-bearing capacity, βThe closer the angle is to 90°, the more purely tensile the fastener bears, and the relatively less shear load, resulting in better fatigue performance. Adjustment x The orientation should be ensured as much as possible. O "Located within the center plane of ear piece 11 (ear piece 11 thickness)" L The bisecting plane of the direction is used to ensure that the load distribution of the fasteners is not too uneven due to additional bending moment when the bolt is under load. It is important to note the ear hole height. h It should not be too large, so as not to incur greater weight costs.

[0026] In step two, loads are screened, and the load direction is confirmed. Within the design load case, the maximum tensile load is selected. F 1 and maximum compressive load F 2 as design load F .

[0027] In step three, the parameters of the ear piece and bushing are designed. The parameter design of the ear piece and bushing includes the ear hole diameter, ear piece width, and ear hole clear edge distance. Since the present invention is a joint designed with an angled ear piece, the end face of the ear piece is located in the angle area where the transverse base 12a and the longitudinal base 12b intersect. The definition of the ear piece width dimension must also take into account the minimum geometric width generated as a result.

[0028] In step four, the initial dimensions of the base connection fasteners are determined based on the load. The size of each fastener connected to the connector base 12 needs to be selected based on the load of that single fastener, choosing an appropriate fastener diameter. The estimated load of a single fastener is as follows: Tensile load according to, ; Shear load according to, ; Step five involves designing the base parameters. This includes the thickness of the base fastener plate, the height of the base flange, and the radius of the transition between the flange and the lug connector. r 1. r 2, the aforementioned r 1. r 2 should be as large as possible to provide the greatest possible stiffness support for the ear plate; In step six, detailed design is performed. After defining the dimensions of the joint, excess material is removed by designing holes to reduce weight, and drainage holes are designed according to actual needs.

[0029] In step seven, the verification margin is checked to ensure it meets the requirements. The verification margin includes checking the tensile and shear strength of the base fasteners, the compressive strength of the nail holes, and the strength of the lugs.

[0030] The base fastener margin is calculated according to the tension-shear coupling equation. Perform failure analysis. Where: tensile load coefficient Shear load factor , The ultimate tensile allowable load under combined loads. This represents the allowable tensile load of the bolt. The ultimate allowable shear load under combined loads. This represents the allowable limit shear load of the bolt.

[0031] Regarding the high-load-bearing lug connector with arbitrary angled placement disclosed in the above embodiments, those skilled in the art will understand that the high-load-bearing lug connector with arbitrary angled placement is typically mounted on the surface of the machine body, and the angled placement angle is... θ This is due to the spatial angle between the load and the transverse and longitudinal elements of the machine body structure.

[0032] For the high load-bearing lug connector with arbitrary angle placement disclosed in the above embodiments, those skilled in the art will understand that the 90° angle between the transverse base 12a and the longitudinal base 12b is not the only possibility; in some alternative embodiments, it can be any angle.

[0033] For the high-load-bearing lug joint with arbitrary angled placement disclosed in the above embodiments, those skilled in the art will understand that the tensile load... F 1 and compressive load F 2 and the bottom surface of the base 12 form an angle β They can be different.

[0034] For the high load-bearing lug joint with arbitrary angled placement disclosed in the above embodiments, those skilled in the art will understand that the 0.75 coefficient used in the calculation of the tensile load of the base fastener in step four of the method takes into account the uneven load of the inner and outer ring fasteners on the base 12, with the inner ring fastener bearing a larger load, which is considered as 75%.

[0035] The high-load-bearing lug connector of the present invention, which is angled at any angle, has the following advantages: Compared with conventional lug connectors, the high-load-bearing connector of the present invention is not affected by the orientation of the body support structure connected to the connector base. It can be reinforced based on the existing arrangement of the body structure, offering high design flexibility and allowing for flexible connector design without affecting the connector's load-bearing performance. The body structure connected to the connector does not require additional reinforcement, resulting in high structural utilization, simplified body support structure, fewer parts, and reduced weight.

[0036] The above description represents preferred embodiments of the present invention, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A high-load-bearing lug connector with an arbitrary angled placement, characterized in that, Include: Ear piece (11), the ear piece (11) is disposed above the base (12); The base (12) includes a horizontal base (12a) and a vertical base (12b). The axis of the ear piece (11) forms an arbitrary angle θ with the longitudinal base (12b); the ear piece (11) is not parallel to the transverse base (12a) and the longitudinal base (12b) arranged laterally and longitudinally. The horizontal base (12a) and the vertical base (12b) intersect each other in a "+" shape and are located on both sides of the ear piece (11); It also includes bushings (13), of which there are two bushings (13), which are respectively installed in the ear holes on both sides of the ear piece (11); The cross-sectional shape of the transverse base (12a) and the longitudinal base (12b) is U-shaped or L-shaped; the mounting base plates of the transverse base (12a) and the longitudinal base (12b) adopt a stepped variable thickness design; the transverse base (12a) and the longitudinal base (12b) are connected to the transverse and longitudinal components of the body structure by four fasteners respectively; the fasteners are arranged in two inner and outer rings, and the inner ring fasteners on both sides of the ear plate (11) axis are arranged on two straight lines with a distance of a and a′ from the ear hole axis respectively, and the outer ring fasteners are arranged on two straight lines with a distance of b and b′ from the ear hole axis respectively.

2. The high load-bearing lug connector according to claim 1, characterized in that, The horizontal base (12a) and the vertical base (12b) intersect each other at 90°.

3. The high load-bearing lug connector according to claim 1, characterized in that, The intersection point O″ of the fastener arrangement lines on the transverse base (12a) and the longitudinal base (12b) is located within the center plane of the ear piece (11) thickness.

4. The high load-bearing lug connector according to claim 1, characterized in that, The ear piece (11) and the base are designed with light-reducing holes as needed.

5. A design method for a high-load-bearing lug connector with an arbitrary angled placement, used to design the lug connector as described in any one of claims 1 to 4, characterized in that, include: Step 1: Coordinate the position of the connector lugs; Step 2: Select loads and confirm load direction; Step 3: Design of ear plate and bushing parameters; Step 4: Determine the initial dimensions of the base connection fasteners based on the load. Step 5: Base parameter design; Step Six: Detailed Design; Step 7: Verify whether the margin meets the requirements.

6. The design method for a high-load-bearing lug joint with an arbitrary angle according to claim 5, characterized in that, In step two, the load includes a tensile load F1 and a compressive load F2.

7. The design method for a high-load-bearing lug joint with an arbitrary angle according to claim 5, characterized in that, In step four, the load estimate required to determine the size of the single fastener connecting the base (12) is as follows: Tensile load according to, ; Shear load according to, ; Where β is the angle between the load F borne by the high load-bearing lug joint and the bottom surface of the base (12).

8. The design method for a high-load-bearing lug joint with an arbitrary angle according to claim 5, characterized in that, In step five, the base parameter design includes the thickness of the base fastener base plate, the height of the base flange, and the transition radii r1 and r2 between the flange and the ear piece joint.

9. The design method for a high-load-bearing lug joint with an arbitrary angle according to claim 5, characterized in that, In step seven, the verification margin includes the tensile and shear strength verification of the base fasteners, the compressive strength verification of the nail holes, and the strength verification of the lugs.

10. A design method for a high-load-bearing lug joint with an arbitrary angle according to claim 9, characterized in that, The verification margin includes the tensile and shear strength verification of the base fasteners, the compressive strength verification of the nail holes, and the strength verification of the lugs; Among them, the base fastener margin is calculated according to the tension-shear joint coupling equation. Perform failure analysis. Where: tensile load coefficient Shear load factor , The ultimate tensile allowable load under combined loads. This represents the allowable tensile load of the bolt. The ultimate allowable shear load under combined loads. This represents the allowable limit shear load of the bolt.

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