Aircraft structural wire displacement restraint apparatus and method

Abstract

The application provides an aircraft structure line displacement constraint device, and belongs to the technical field of aircraft structure strength test. The constraint device comprises a wall plate, the edge of the wall plate is provided with a plurality of constraint holes, and the continuous structure is simplified into a finite point constraint structure; a supporting plate is provided with mounting holes matched with the constraint holes on the wall plate, and mounting seats are mounted in the mounting holes; constraint pieces are hingedly connected with the constraint holes of the wall plate and the mounting seats of the supporting plate, the pre-tightening force of the supporting plate on the wall plate reaches a predetermined value by adjusting the length of the constraint pieces, and the constraint pieces only constrain the line displacement of the wall plate in the extension direction of the disconnected section, and release the freedom in other directions. The aircraft structure line displacement constraint device and method can better simulate the constraint state of the edge strip or the wall plate, solve the problems of over-constraint, stress concentration, stress distribution distortion and the like caused by the traditional direct fixed support, and meet the requirements of the aircraft structure strength test.

Description

Technical Field

[0001] The present invention relates to the field of aircraft structure strength testing, and in particular to a method for constraining aircraft structure linear displacement. Background Art

[0002] When extracting test pieces through aircraft component testing, it is often necessary to cut off the fuselage or wing structure, and the ribs or frame edges and panels need to be constrained during test support. Figure 1 The schematic diagram of the constraint structure 10 of the corner box direct fixation is shown, and the wall plate 11 and the support plate 12 are connected by bolts 14 passing through the corner box 13 to achieve the fixation of the two, or as shown in FIG. Figure 2 The schematic diagram of the restraint structure 20 with a post-transition plate fixation is shown. Bolts 24 passing through corner boxes 23 transition through strip plates 25, connecting the wall panel 21 and support plate 22 to secure both. However, conventional restraint methods, when located in non-critical areas or with a long transition zone, do not require significant consideration of the impact of overconstraint on stress distribution. However, conventional solutions cannot meet the requirements for obtaining stress distribution near the wall panel cross section, simulating the actual restraint state as accurately as possible, or strictly controlling stress levels in the restraint zone. Summary of the Invention

[0003] The purpose of the present application is to provide an aircraft structure linear displacement restraint device to solve or alleviate at least one problem in the background art.

[0004] The technical solution of this application is: an aircraft structure linear displacement constraint device, comprising:

[0005] A wall panel, wherein the edge of the wall panel is provided with a plurality of constraint holes for simplifying the continuous structure into a finite point constraint structure;

[0006] A supporting plate, wherein the supporting plate is provided with a mounting hole adapted to fit the constraint hole on the wall plate, and a mounting seat is installed in the mounting hole; and

[0007] The restraint member is hinged to the restraint hole of the wall panel and the mounting seat of the supporting plate respectively. By adjusting the length of the restraint member, the pre-tightening force of the supporting plate on the wall panel reaches a predetermined value. The restraint member only constrains the linear displacement in the extension direction of the broken section wall panel, releasing the degrees of freedom in other directions.

[0008] In an optional embodiment of the present application, a reinforcement is further included, which is fixedly arranged at the edge of the wall panel, and a constraint hole is provided on the reinforcement. The constraint member is connected to the constraint hole on the reinforcement to perform preload.

[0009] In an optional embodiment of the present application, the reinforcement is a flat plate structure.

[0010] In an optional embodiment of the present application, the mounting base on the supporting plate is a double-ear mounting base, and the double-ear mounting base is provided with a screw, which is fixed to the supporting plate by a nut after passing through the mounting hole.

[0011] In an optional embodiment of the present application, the restraining member includes a double-ear screw, a single-ear screw and a screw sleeve. One side of the double-ear screw is a double-ear structure and the other side is a screw structure. The double-ear structure is hinged to the restraining hole through bolts. One side of the unit screw is a single-ear structure and the other side is a screw structure. The single-ear structure is hinged to the mounting seat of the supporting plate through bolts. The screw sleeve cooperates with the double-ear screw and the single-ear screw, and the double-ear screw and the single-ear screw are moved closer or farther away by rotating the screw sleeve.

[0012] In an optional embodiment of the present application, the screw portion of the double-ear screw and the screw portion of the single-ear screw have opposite thread rotation directions.

[0013] In an optional embodiment of the present application, the threaded pairs of the double-ear screw and the bolt at the constraint hole, the single-ear screw and the bolt at the mounting seat and the screw sleeve release three degrees of rotational freedom, and the reserved gaps between the double-ear screw and the reinforcement, and the single-ear screw and the mounting seat release two linear displacements, thereby forming a linear displacement that only constrains the axial direction of the screw sleeve.

[0014] In addition, the present application also provides a method for constraining aircraft structure linear displacement using any of the above-mentioned aircraft structure linear displacement constraint devices, comprising:

[0015] Connect the two ends of the restraint member to the restraint hole and the mounting seat on the support plate respectively;

[0016] By adjusting the length of the restraint, the tensile preload or compressive preload on the wall panel can be adjusted, and the preload applied to the wall panel can be obtained at the same time;

[0017] During the test pre-test or loading process, the tightness of the restraints on the wall panels is further adjusted according to the obtained preload force to achieve the goals expected by the test designers.

[0018] In an optional embodiment of the present application, when adjusting the tensile preload or compressive preload on the wall panel by adjusting the length of the restraint, a tightening torque is applied to the restraint according to the designed tightening torque so that the restraint applies a predetermined preload on the wall panel, or a strain gauge is pasted on the test piece and the length of the restraint is adjusted according to the measured value of the strain gauge so that the restraint applies a predetermined preload on the wall panel.

[0019] In an optional embodiment of the present application, the strain gauge is a resistance strain gauge.

[0020] The aircraft structure linear displacement constraint device and method of the present application can better simulate the constraint state of edge strips or wall panels, solve the problems of over-constraint, stress concentration, and stress distribution distortion caused by traditional direct fixturing, and meet the requirements of aircraft structure strength testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0022] Figure 1 Schematic diagram of the constraint structure of the corner box directly fixed in the prior art.

[0023] Figure 2 This is a schematic diagram of the constraint structure of the post-transition fixed support of the strip plate in the prior art.

[0024] Figure 3 This is a schematic diagram of the aircraft structure linear displacement constraint device of this application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0026] The present application provides an aircraft structure linear displacement constraint device and method, which only constrains the linear displacement in the extension direction of the broken cross-section of the aircraft structure while releasing other degrees of freedom. The prestress level in the constrained area can be controlled as needed, solving problems such as over-constraint, stress concentration, and stress distribution distortion caused by traditional clamped structures. By setting adjustable characteristics, the fault tolerance of the test design is improved.

[0027] like Figure 3 As shown, the aircraft structure linear displacement restraint device of the present application includes:

[0028] The wall panel 31 has a plurality of constraint holes 312 on its edge according to the number of constraint points required, thereby simplifying the continuous structure into a finite point constraint structure;

[0029] A support plate 33 is fixed to a tripod 34 via studs 341. The tripod 34 is fixed to the load-bearing floor of the laboratory. The support plate 33 is provided with a plurality of mounting holes 331 adapted to the constraint holes 312 on the wall panel 31. The mounting holes 331 are provided with mounting seats 332. The support plate 33 provides rigid support for the constraint component 32.

[0030] Multiple restraints 32 are hinged to the mounting bases 332 of the wall panel 31 and the supporting plate 33 respectively. By adjusting the length of the restraints 32, the preload force between the wall panel 31 and the supporting plate 33 reaches a predetermined value. The restraints 32 only restrain the linear displacement in the extension direction (tangential direction) of the broken section wall panel, and release (or limitedly release) the degrees of freedom in the other five directions.

[0031] In some embodiments of the present application, after the constraint holes 312 are provided on the wall panel 31, the stress on the wall panel 31 is more concentrated under a constant load. To prevent premature damage to the edge of the wall panel 31, a reinforcement member 311 is provided on the edge of the wall panel 31 for local reinforcement. In some embodiments, the reinforcement member 311 is a flat plate structure, one side of which is fixedly connected to the edge of the wall panel 31 by bolts or welding, and the other side is provided with the constraint hole 312.

[0032] In some embodiments of the present application, the mounting holes 331 on the supporting plate 33 are arranged according to certain rules. For example, multiple rows or columns of mounting holes 331 can be arranged in a straight line on the supporting plate 33 to adapt to the constraint holes on the wall panel 31 or the reinforcement 311.

[0033] In the present application, the mounting seat 332 is a double-ear mounting structure, and a screw is provided on the back side thereof. After the screw passes through the mounting hole 331, the mounting seat 332 can be fixed on the supporting plate 33 by being locked by a nut.

[0034] In one embodiment of the present application, the constraint member 32 includes a double-ear screw 321, a single-ear screw 322, and a screw sleeve 323. The double-ear screw 321 has a double-ear structure at one end and a screw at the other end. The double-ear structure is used to mate with the constraint hole 312 on the wall panel 31 or the reinforcement member 311, and is hinged by bolts. The single-ear screw 322 has a single-ear structure at one end and a screw at the other end. The single-ear structure is used to mate with the mounting base 332 on the support plate 33, and is hinged by bolts. The screw sleeve 323 is threadedly engaged with the screw portions of the double-ear screw 321 and the single-ear screw 322. By rotating the screw sleeve 323, the double-ear screw 321 and the single-ear screw 322 can be moved closer or farther apart, thereby adjusting the length of the constraint member 32. For example, the threads of the screw portions of the double-ear screw 321 and the single-ear screw 322 can be arranged in opposite directions, so that the double-ear screw 321 and the single-ear screw 322 can be moved closer or farther apart. Furthermore, the hinge axis formed by the double-ear screw 321 and the restraining hole 312 of the wall plate 31 or the reinforcement 311 is orthogonal to the hinge axis formed by the single-ear screw 322 and the mounting seat 332 .

[0035] The threaded pairs of the double-ear screw 321 and the bolt at the constraint hole 312 of the wall panel 31 or the reinforcement 311, the single-ear screw 322 and the bolt at the mounting seat 332, and the screw sleeve 323 release three degrees of rotational freedom, and the reserved gaps between the double-ear screw 321 and the reinforcement 311, and the single-ear screw 322 and the mounting seat 332 release two linear displacements, thereby forming a linear displacement that only constrains the axial direction of the screw sleeve 323.

[0036] In addition, the present application also provides a method for constraining aircraft structure linear displacement using the above-mentioned aircraft structure linear displacement constraint device, the method comprising:

[0037] S10, connecting the two ends of the restraining member 32 to the restraining hole 312 and the mounting seat 332 on the supporting plate 33 respectively;

[0038] S20, adjusting the tension / compression preload on the wall panel 31 by rotating and adjusting the length of the restraining member 32;

[0039] Among them, a tightening torque can be applied to the screw sleeve 323 of the constraint 32 according to the designed tightening torque, so that the constraint 32 applies a predetermined tensile / compressive pre-tightening force to the wall panel 31; or a strain gauge 313 can be pasted on the test piece (edge ​​strip, wall panel or other part), and the measurement value of the strain gauge 313 is adjusted to a preset value, so that the constraint 32 applies a predetermined tensile / compressive pre-tightening force to the wall panel 31.

[0040] Preferably, the strain gauge is a resistance strain gauge;

[0041] S30, during the test pre-test or loading process, the tightness of the screw sleeve 323 can be further adjusted according to the strain value measured by the strain gauge 313 to achieve the goal expected by the test designer.

[0042] This application takes the air inlet lip test of an aircraft as an example to provide a more detailed explanation of the constraint structure and method of this application.

[0043] The air intake structure is bilaterally symmetrical, and the left side was selected for testing. Longitudinal and transverse skeletal beams were arranged at the bottom of the test specimen for fixed support. On the right side of the test specimen, the flanges and struts of the end ribs (divided into upper and lower sections) were reinforced at the structural cutoff point, with restraint points installed and linear displacement restraints implemented according to the structure and methods of this application. After strength verification, the flanges were reinforced with two upper and lower 75mm wide, 3mm thick aluminum plates and extended by 50mm (with a 3mm thick aluminum plate in the middle, the same thickness as the flanges as the flanges). These were connected using a 5mm diameter bolt assembly with 25mm spacing. Prefabricated 12mm diameter restraint holes 312 were used at the flange restraint points and connected to the double-lug screws 321 of the restraint member 32 with 12mm diameter bolts. Seven restraint points were provided on each flange. The pillars were reinforced, extended, and restrained in the same manner as the flanges, with three restraint points on the front and middle columns and one on the rear flange. The single-lug screw 322 was bolted to the double-lug mounting bracket of the support plate 33. Support plate 33 is secured to tripod 34 with studs 341, which is then fixed to the laboratory's load-bearing floor. The two-ear mounting bracket is secured to prefabricated mounting holes 331 in support plate 33 with nuts. The linear displacement constraint method and parameters for the upper and lower parts of the disconnect structure are identical.

[0044] Because the left and right intake ducts are structurally symmetrical and loaded symmetrically, and the cutoff point is located near the plane of structural symmetry, it can be assumed that the structural displacement along the outer extension of the cutoff is zero. During the test, the same tightening torque (5 N·m) was applied to the constraint screw 323 at each constraint point to ensure consistent prestress at each constraint point. During the test loading, each constraint point was passively loaded due to structural deformation. Except for the linear displacement of the active constraint, the other five degrees of freedom were released. No binding was observed, and the test was successfully completed.

[0045] The aircraft structure linear displacement constraint device and method of the present application can better simulate the constraint state of edge strips or wall panels, solving the problems of over-constraint, stress concentration, and stress distribution distortion caused by traditional direct fixturing, meeting the requirements of aircraft structure strength testing, and its adjustable constraint method improves the fault tolerance of the test, avoiding the loss of time and benefits caused by inappropriate fixture design and inability to adjust. The structure and method of the present application are simple in principle, the fixture is easy to process, and some fixtures are reusable, with high cost-effectiveness and good feasibility. It also has advantages in improving resource utilization and reducing environmental pollution.

[0046] The structure and method of the present application have been successfully applied in experiments, solving the problem of unidirectional linear displacement constraints, meeting engineering needs, improving test quality, and also having good effects in improving resource utilization and reducing environmental pollution.

[0047] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An aircraft structure linear displacement restraint device, characterized in that: include: A wall panel, wherein the edge of the wall panel is provided with a plurality of constraint holes for simplifying the continuous structure into a finite point constraint structure; A supporting plate, wherein the supporting plate is provided with a mounting hole adapted to fit the constraint hole on the wall plate, and a mounting seat is installed in the mounting hole; and The restraint member is hinged to the restraint hole of the wall panel and the mounting seat of the supporting plate respectively. By adjusting the length of the restraint member, the pre-tightening force of the supporting plate on the wall panel reaches a predetermined value. The restraint member only constrains the linear displacement in the extension direction of the broken section wall panel, releasing the degrees of freedom in other directions.

2. The aircraft structure linear displacement restraint device according to claim 1, characterized in that: It also includes a reinforcement member, which is fixedly arranged at the edge of the wall panel. A constraint hole is arranged on the reinforcement member, and the constraint member is connected to the constraint hole on the reinforcement member to perform preload.

3. The aircraft structure linear displacement restraint device according to claim 2, characterized in that: The reinforcement is a flat plate structure.

4. The aircraft structure linear displacement restraint device according to claim 1 or 2, characterized in that: The mounting base on the support plate is a double-ear mounting base, and the double-ear mounting base is provided with a screw rod, which is fixed on the support plate by a nut after passing through the mounting hole.

5. The aircraft structure linear displacement restraint device according to claim 4, characterized in that: The restraining part includes a double-ear screw, a single-ear screw and a screw sleeve. One side of the double-ear screw is a double-ear structure and the other side is a screw structure. The double-ear structure is hinged to the restraining hole through bolts. One side of the unit screw is a single-ear structure and the other side is a screw structure. The single-ear structure is hinged to the mounting seat of the supporting plate through bolts. The screw sleeve cooperates with the double-ear screw and the single-ear screw. The double-ear screw and the single-ear screw are moved closer or farther away by rotating the screw sleeve.

6. The aircraft structure linear displacement restraint device according to claim 5, characterized in that: The screw portion of the double-ear screw and the screw portion of the single-ear screw have threads that rotate in opposite directions.

7. The aircraft structure linear displacement restraint device according to claim 6, characterized in that: The threaded pairs of the double-ear screw and the bolt at the constraint hole, the single-ear screw and the bolt at the mounting seat and the screw sleeve release three rotational degrees of freedom, and the reserved gaps between the double-ear screw and the reinforcement, and the single-ear screw and the mounting seat release two linear displacements, thereby forming a linear displacement that only constrains the axial direction of the screw sleeve.

8. A method for constraining aircraft structure linear displacement using the aircraft structure linear displacement constraint device according to any one of claims 1 to 7, characterized in that: include: Connect the two ends of the restraint member to the restraint hole and the mounting seat on the support plate respectively; By adjusting the length of the restraint, the tensile preload or compressive preload on the wall panel can be adjusted, and the preload applied to the wall panel can be obtained at the same time; During the test pre-test or loading process, the tightness of the restraints on the wall panels is further adjusted according to the obtained preload force to achieve the goals expected by the test designers.

9. The method according to claim 8, wherein When adjusting the tensile preload or compressive preload on the wall panel by adjusting the length of the restraint, a tightening torque is applied to the restraint according to the designed tightening torque so that the restraint applies a predetermined preload on the wall panel, or a strain gauge is attached to the test piece and the length of the restraint is adjusted according to the measured value of the strain gauge so that the restraint applies a predetermined preload on the wall panel.

10. The method according to claim 9, wherein The strain gauge is a resistance strain gauge.

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