An equivalent simulation method and device for the boundary stiffness of an aircraft panel impact test

Abstract

The present invention discloses a method and device for equivalent simulation of the boundary stiffness of an aircraft panel impact test, belonging to the technical field of aircraft ground tests. The equivalent simulation device of the present invention uses a local panel test piece to replace the overall fuselage frame for impact tests. A support bench is arranged on the base. Based on the support bench, a vertical stiffness simulation spring assembly and a bending stiffness simulation device are carried. A torsional stiffness simulation spring assembly and a longitudinal stiffness simulation spring assembly are arranged on the bending stiffness simulation device, and a local panel test piece is installed on the bending stiffness simulation device. The simulation device decomposes the boundary stiffness of the aircraft panel when being impacted into torsional stiffness, vertical stiffness and longitudinal stiffness, so that the boundary stiffness is transformed into three groups of linear springs in different directions for stiffness simulation. While ensuring the accurate simulation of the boundary stiffness, the decoupling of the boundary stiffness simulation is also achieved, reducing the design difficulty of the test device.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft ground tests, and particularly relates to a method and device for equivalent simulation of the boundary stiffness of aircraft panel impact tests. Background Art

[0002] Ground service equipment refers to various equipment required to support an aircraft when it is docked at an airport. Such equipment includes, but is not limited to, various ground service vehicles, boarding bridges, gangways, maintenance gantries, and baggage handling equipment. Since these ground service equipment are usually used when the aircraft is docked on the ground, their accidental collisions with the aircraft fuselage structure have become a common cause of damage to civil aircraft fuselage structures. According to investigations, up to 50% of the serious damage to civil aircraft fuselage structures is caused by accidental collisions during the operation of baggage loading and unloading vehicles, and 60% of the minor damage is related to direct contact with airport ground vehicles or equipment.

[0003] In new-generation aircraft, composite panel structures are widely used. When such structures are impacted, although there may be no obvious visible damage such as structural deformation, dents, or cracks, it may cause serious internal damage to the structure. These internal damages may include damage to the fuselage frame, debonding of ribs or shear bands, shear failure of bolts, and fracture of ribs. These damages will seriously reduce the performance of the aircraft structure and may pose a threat to flight safety.

[0004] To ensure the safety of an aircraft during service, it is essential to conduct low-speed impact tests on the composite structure of the aircraft fuselage by ground service equipment. However, existing aircraft impact research mainly focuses on the impact on the aircraft during landing, such as the patent application with the publication number CN111929019A, which discloses a ground test device for simulating the landing impact process of a carrier-based aircraft landing gear, and the patent application with the publication number CN117109861B, which discloses a patent for simulating the relative movement between the wheels and the ground in a laboratory environment and further measuring the ground impact load of the wheels.

[0005] However, the above-mentioned existing technologies lack relevant research on the collision situation between ground service equipment and aircraft, and it is difficult to estimate the impact on the aircraft panel when the ground service equipment collides with the aircraft. Summary of the Invention

[0006] The object of the present invention is to overcome the above-mentioned shortcomings of the existing technology and provide a method and device for equivalent simulation of the boundary stiffness of aircraft panel impact tests, so as to solve the problem in the existing technology that there is a lack of relevant research on the collision between ground service equipment and aircraft, and it is difficult to estimate and judge the damage caused to the aircraft panel during relevant impacts.

[0007] To achieve the above object, the present invention is implemented by the following technical solutions:

[0008] An aircraft panel impact test boundary stiffness equivalent simulation device, comprising a base, and a support frame is arranged on the base;

[0009] The front end of the support frame is connected with a vertical support plate through a plurality of vertical stiffness simulation spring assemblies;

[0010] At the front end of the vertical support plate, there are arranged a plurality of bending stiffness simulation devices in the upper row and a plurality of bending stiffness simulation devices in the lower row which are opposite up and down; the plurality of bending stiffness simulation devices in the upper row are fixedly connected with the vertical support plate, and the plurality of bending stiffness simulation devices in the lower row are slidably connected with the vertical support plate;

[0011] The bending stiffness simulation device comprises a longitudinal connecting plate arranged at the front end of the vertical support plate, the front end of the longitudinal connecting plate is connected with two longitudinal fixing plates, two longitudinal fixing plates jointly rotatably connect a connecting plate, two longitudinal fixing plates jointly connect a torsional stiffness simulation spring assembly, and the front end of the connecting plate abuts against the rear end of the torsional stiffness simulation spring assembly;

[0012] The lower ends of the two longitudinal fixing plates in the bending stiffness simulation device in the lower row are jointly connected with a longitudinal stiffness simulation spring assembly, and the longitudinal stiffness simulation spring assembly is arranged on the vertical support plate;

[0013] The connecting plates in the bending stiffness simulation devices in the upper row and the connecting plates in the bending stiffness simulation devices in the lower row jointly connect a local panel test piece.

[0014] A further improvement of the present invention lies in:

[0015] Preferably, the vertical stiffness simulation spring assembly comprises a connecting support column and a vertical compression spring, the rear end of the connecting support column is connected with the support frame, the front end of the connecting support column is slidably connected with the vertical support plate, and the vertical compression spring is sleeved on the connecting support column between the vertical support plate and the support frame.

[0016] Preferably, four vertical stiffness simulation spring assemblies are provided, and are respectively arranged at the four top corners of the rear end face of the vertical support plate.

[0017] Preferably, a longitudinal slider is arranged on the rear end face of the longitudinal connecting plate of the bending stiffness simulation device in the lower row, and a longitudinal slide rail is arranged at the front end of the vertical support plate, and the longitudinal slide rail is slidably connected with the longitudinal slider.

[0018] Preferably, the bottom end of the longitudinal fixing plate of the bending stiffness simulation device in the lower row is connected with a horizontal fixing plate, and the bottom of the horizontal fixing plate is connected with the longitudinal stiffness simulation spring assembly.

[0019] Preferably, the longitudinal stiffness simulation spring assembly includes a horizontal support plate disposed at the front end of the vertical support plate. A limit ring is provided on the horizontal support plate, and the limit ring is sleeved outside the longitudinal support spring. The upper end of the longitudinal support spring is connected to the horizontal fixing plate, and the lower end of the longitudinal support spring is connected to the horizontal support plate.

[0020] Preferably, a rotating shaft is provided between the protruding portions of the two longitudinal fixing plates; the concave portions of the longitudinal fixing plates are connected to the torsional stiffness simulation spring assembly through U-shaped connectors.

[0021] Preferably, the torsional stiffness simulation spring assembly includes two connecting screws. The inner end of each connecting screw is connected to the U-shaped connector. A push plate is slidably connected to the two connecting screws together. A limiting plate is connected to the outer ends of the two connecting screws together. A torsional compression spring is sleeved on the connecting screw between the push plate and the limiting plate; the connecting plate abuts against the rear end of the push plate.

[0022] Preferably, the connecting plate includes a rotatably connecting portion and a supporting connecting portion which are integrally connected. The width of the rotatably connecting portion is greater than the width of the supporting connecting portion; the front end of the rotatably connecting portion abuts against the rear end of the torsional stiffness simulation spring assembly, and the supporting connecting portion is connected to the local wall panel test piece.

[0023] An aircraft panel impact test boundary stiffness equivalent simulation method based on the above simulation device includes the following steps:

[0024] S1, respectively connect the upper and lower ends of the frames of the local wall panel test piece to the connecting plates in two rows of bending stiffness simulation devices;

[0025] S2, perform an impact test on the local wall panel test piece. During the impact test, disperse the vertical stiffness through the vertical stiffness simulation spring assembly, disperse the torsional stiffness through the torsional stiffness simulation spring assembly, and disperse the longitudinal stiffness through the longitudinal stiffness simulation spring assembly.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention discloses an equivalent simulation device for the boundary stiffness of an aircraft panel impact test. In this equivalent simulation device, a support bench is arranged on a base. Based on the support bench, a vertical stiffness simulation spring assembly and a bending stiffness simulation device are connected in front of the support bench. A torsional stiffness simulation spring assembly and a longitudinal stiffness simulation spring assembly are arranged on the bending stiffness simulation device. The boundary stiffness of the aircraft panel when subjected to impact is decomposed into torsional stiffness, vertical stiffness, and longitudinal stiffness, and the three decomposed stiffnesses are transformed into three groups of linear springs in different directions for stiffness simulation. This method ignores the influence of lateral stiffness, ensuring accurate simulation of the boundary stiffness while also achieving decoupling of the boundary stiffness simulation and reducing the design difficulty of the test device. During the test process, a test piece in the form of a local panel is used to replace the overall fuselage frame, simulating the scenario of accidental impact of airport ground equipment on the aircraft fuselage structure in a laboratory environment, making the deformation mode and failure behavior of the test piece in the form of a local panel consistent with those of the overall fuselage barrel section, and ensuring the consistency of the boundary stiffness, thereby ensuring the authenticity and reliability of the impact resistance characteristics of the fuselage composite material structure, and significantly reducing the test cost and test difficulty.

[0028] Further, the vertical stiffness simulation spring assembly is stressed by a vertically compressed spring, so that when the entire vertical support plate is subjected to an impact force, it can simulate the vertical stiffness.

[0029] Further, four vertical stiffness simulation spring assemblies are provided, which are respectively arranged at the four top corners of the vertical support plate. When subjected to an impact force, the entire vertical support plate is uniformly stressed.

[0030] Further, in the lower row of bending stiffness simulation devices, the longitudinal connecting plate enables the lower row of bending stiffness simulation devices to move downward through the cooperation of a longitudinal slider and a longitudinal slide rail during the process of deformation of the local panel test piece caused by an impact force.

[0031] Further, the bottom end of the longitudinal fixing plate is connected to the longitudinal stiffness simulation spring assembly through a horizontal fixing plate, while the connecting plate is connected to the local panel test piece, so that when the local panel test piece is impacted, the longitudinal stiffness simulation spring assembly can give a certain supporting force to the entire bending stiffness simulation device and can simulate the dispersed longitudinal stiffness.

[0032] Further, the longitudinal stiffness simulation spring assembly includes a longitudinal support spring and a limit ring sleeved outside the longitudinal support spring. Through the cooperation of the longitudinal support spring, the longitudinal slide rail, and the longitudinal slider, when all the lower row of bending stiffness simulation devices move downward, the longitudinal support spring can give a certain buffer to the bending stiffness simulation device.

[0033] Furthermore, there are two longitudinal fixing plates. A rotating shaft is arranged between the two longitudinal fixing plates. Through the rotational connection between the rotating shaft and the connecting plate, the connection between the local panel test piece and the equivalent simulation device is realized.

[0034] Furthermore, the torsional stiffness simulation spring assembly is provided with a pushing plate, a limiting plate, and a torsional compression spring arranged between the pushing plate and the limiting plate. When the connecting plate is deformed by an external force, the bottom of the connecting plate will push the pushing plate forward to realize the transmission of the torsional force. The torsional stiffness simulation spring assembly can simulate the distributed torsional stiffness.

[0035] Furthermore, the structure of the connecting plate is that the rotational connection part is wide and the supporting connection part is narrow, so as to enhance the connection strength of the entire connecting plate. At the same time, the wider rotational connection part can better disperse the torsional stiffness.

[0036] The present invention also discloses a method for equivalently simulating the boundary stiffness of an aircraft panel impact test. In this method, the upper and lower ends of the frames of the local panel test piece are respectively connected to the connecting plate, so that the local panel test piece is installed on the entire equivalent simulation device for simulation tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a three-dimensional structural schematic diagram of the boundary stiffness simulation device of the present invention;

[0038] Figure 2 is a side view of the three-dimensional structure of the boundary stiffness simulation device of the present invention;

[0039] Figure 3 is a structural schematic diagram of the support stand and the base of the present invention;

[0040] Figure 4 is a detailed three-dimensional structure diagram of the boundary stiffness simulation device of the present invention;

[0041] Figure 5 of the present invention Figure 4 is an enlarged view of area A;

[0042] Figure 6 of the present invention Figure 4 is an enlarged view of area B;

[0043] Figure 7 is a structural schematic diagram of the torsional stiffness simulation spring assembly and the longitudinal stiffness simulation spring assembly of the present invention.

[0044] Wherein: 1. Local panel test piece; 2. Bending stiffness simulation device; 3. Vertical compression stiffness simulation device; 4. Support stand; 5. Base; 101. Skin; 102. Longeron; 103. Frame; 201. Connecting plate; 202. Rotating shaft; 203. Torsional stiffness simulation spring assembly; 204. Longitudinal slide rail; 205. Longitudinal stiffness simulation spring assembly; 206. Longitudinal slider; 207. Longitudinal connecting plate; 208. Longitudinal fixing plate; 209. Horizontal fixing plate; 301. Vertical support plate; 302. Vertical stiffness simulation spring assembly; 2010. U-shaped connecting piece; 2011. Rotating connection part; 2012. Support connection part; 2031. Pushing plate; 2032. Connecting screw; 2033. Torsional compression spring; 2034. Limiting plate; 2051. Horizontal support plate; 2052. Limiting ring; 2053. Longitudinal support spring; 2081. Protrusion; 2082. Depression; 3011. Observation plate; 3021. Connecting support column; 3022. Vertical compression spring. Detailed implementation manners

[0045] The present invention will be further described in detail below with reference to the accompanying drawings:

[0046] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0047] See Figure 1 and Figure 5 As shown in and, a boundary stiffness equivalent simulation device for aircraft panel impact test is disclosed in the first aspect of the present invention. The main structure of the device includes a bending stiffness simulation device 2, a vertical compression stiffness simulation device 3, a support stand 4, a base 5, a torsional stiffness simulation spring assembly 203 and a longitudinal stiffness simulation spring assembly 205. The support stand 4 is arranged on the base 5, the vertical compression stiffness simulation device 3 is arranged on the front side of the support stand 4, and the support stand 4 is on the rear side of the vertical compression stiffness simulation device 3. Taking this as the reference direction, it will not be elaborated hereinafter. The bending stiffness simulation device 2 is arranged on the vertical compression stiffness simulation device 3, the torsional stiffness simulation spring assembly 203 is arranged on the bending stiffness simulation device 2, and the longitudinal stiffness simulation spring assembly 205 is connected to the bending stiffness simulation device 2.

[0048] See Figure 1 and Figure 2, during the test, the local panel test piece 1 of the aircraft is installed in front of the vertical compression stiffness simulation device 3 and connected to the bending and compression stiffness simulation device 2 at the same time. The local panel test piece 1 includes a skin 101, stringers 102 and frames 103. The stringers 102 are arranged along the axis direction of the entire fuselage, and the frames 103 are arranged along the circumferential direction of the entire fuselage. The stringers 102 and the frames 103 are connected by shear bands, and the stringers 102 are perpendicular to the plane where the frames 103 are located. Figure 2 The vertical arc in the local panel test piece 1 shown in Figure 2 is the frame 103, the horizontal one is the stringer 102, and the skin 101 is arranged outside the stringers 102 and the frames 103.

[0049] In the present invention, the direction perpendicular to the center of the outer surface of the local panel test piece 1 and pointing to the center point of the local panel test piece 1 is defined as the vertical direction, that is, the impact direction of the ground service equipment, which is the horizontal direction; the direction passing through the impact point and tangent to the frame 103 is defined as the longitudinal direction, which is the vertical direction; the direction along the stringer 102 is defined as the transverse direction, that is, the axis direction or the heading direction of the aircraft, which is the horizontal direction.

[0050] See Figure 2 and Figure 3 , the base 5 is arranged at the bottom. During the test, the base 5 is fixedly arranged on the ground. The support platform 4 is fixedly arranged on the base 5 through a plurality of fixing bolts. The support platform 4 is a frame structure welded by square steel and is internally provided with a plurality of support frames. Some of the support frames are inserted into the interior of the base 5 and fixedly connected to the interior of the base 5 through bolts to enhance the connection force between the support platform 4 and the base 5.

[0051] Furthermore, a horizontal transverse plate is arranged at the middle position of the support platform 4 to enhance the support capacity of the entire support platform 4.

[0052] See Figure 4, in some embodiments of the present invention, the vertical compression stiffness simulation device 3 includes a vertical support plate 301 and a plurality of vertical stiffness simulation spring assemblies 302. The vertical support plate 301 is fixedly arranged in front of the support frame 4, and the vertical support plate 301 is connected to the support frame 4 through four vertical stiffness simulation spring assemblies 302. Each vertical stiffness simulation spring assembly 302 includes a horizontally arranged connecting support column 3021 and a vertical compression spring 3022. The rear end of the connecting support column 3021 is connected to the support frame 4, and the front end passes through the vertical support plate 301. A limit block is arranged at the front end of the connecting support column 3021. The limit block is at the front end of the vertical support plate 301, and the area of the limit block is larger than the area of the hole opened on the vertical support plate 301 through which the connecting support column 3021 passes, preventing the vertical support plate 301 from slipping off the connecting support column 3021. A vertical compression spring 3022 is sleeved on the connecting support column 3021 between the vertical support plate 301 and the support frame 4. The rear end of the vertical compression spring 3022 is fixedly connected to the front end of the support frame 4, and the front end is a free end and abuts against the vertical support plate 301.

[0053] As a preferred solution, four vertical stiffness simulation spring assemblies 302 are respectively arranged at the four corners of the vertical support plate 301, so that when performing the impact test, the force on the support frame 4 is uniform.

[0054] See Figure 1 and Figure 4 , two rows of bending stiffness simulation devices 2 are arranged at the front end of the vertical support plate 301, namely the upper row of bending stiffness simulation devices 2 and the lower row of bending stiffness simulation devices 2. A plurality of bending stiffness simulation devices 2 are arranged in each row. The number of the upper row of bending stiffness simulation devices 2 and the lower row of bending stiffness simulation devices 2 is equal and vertically aligned, and the bending stiffness simulation devices 2 in each row are horizontally aligned. The upper row of bending stiffness simulation devices 2 is fixedly connected to the vertical support plate 301, and the lower row of bending stiffness simulation devices 2 is slidably connected to the vertical support plate 301.

[0055] See Figure 4 , as a preferred solution, an observation plate 3011 is arranged on the vertical support plate 301. The observation plate 3011 is made of transparent acrylic material, which is convenient for observing the deformation of the local wall panel test piece 1 during the impact process.

[0056] In some specific embodiments of the present invention, the support frame 4 is of a frame structure and an observation plate 3011 is arranged on the vertical support plate 301, which is convenient for observing the deformation of the local wall panel test piece 1 from the rear side of the support frame 4.

[0057] See Figure 5 、 Figure 6 and Figure 7, each bending stiffness simulation device 2 includes a connecting plate 201, a rotating shaft 202, a longitudinal connecting plate 207, a longitudinal fixing plate 208, a horizontal fixing plate 209, and a U-shaped connecting member 2010.

[0058] See Figure 5 , Figure 6 and Figure 7 , the longitudinal connecting plate 207 is parallel to the vertical support plate 301. In the upper row of bending stiffness simulation devices 2, the longitudinal connecting plate 207 and the vertical support plate 301 are fixedly connected by bolts. In the lower row of bending stiffness simulation devices 2, the longitudinal connecting plate 207 and the vertical support plate 301 are slidably connected. The front end of each longitudinal connecting plate 207 is fixedly connected with two longitudinal fixing plates 208 and a horizontal fixing plate 209. The lower ends of the two longitudinal fixing plates 208 are connected to the horizontal fixing plate 209. The longitudinal connecting plate 207, the longitudinal fixing plate 208, and the horizontal fixing plate 209 are perpendicular to each other in pairs.

[0059] See Figure 5 , Figure 6 and Figure 7 , the longitudinal fixing plate 208 is divided into a protruding part 2081 and a recessed part 2082 which are integrally connected. The protruding part 2081 is on the upper side of the recessed part 2082. The width of the protruding part 2081 is greater than that of the recessed part 2082, that is, the protruding part 2081 protrudes more forward relative to the recessed part 2082. A rotating shaft 202 is fixedly connected between the two protruding parts 2081. A connecting plate 201 is rotatably connected to the rotating shaft 202. The recessed part 2082 is connected with a U-shaped connecting member 2010 by bolts. The two sides of each U-shaped connecting member 2010 are connected to the recessed part 2082 by bolts. The middle part of each U-shaped connecting member 2010 is connected with a torsional stiffness simulation spring assembly 203.

[0060] See Figure 5 , in the lower row of bending stiffness simulation devices 2, the rear end of the longitudinal connecting plate 207 is fixedly connected with four longitudinal sliders 206. The four longitudinal sliders 206 are vertically aligned in pairs and horizontally aligned in pairs. Two longitudinal sliders 206 in the same vertical direction and a longitudinal slide rail 204 are slidably connected. Each longitudinal slide rail 204 is fixedly arranged on the vertical support plate 301.

[0061] See Figure 5 , Figure 6 and Figure 7, the torsional stiffness simulation spring assembly 203 includes a push plate 2031, two connecting screws 2032, two torsional compression springs 2033 and a limit plate 2034. The rear end of each connecting screw 2032 passes through the push plate 2031 and is connected to the middle part of a U-shaped connecting piece 2010. The front ends of the two connecting screws 2032 are jointly connected to the limit plate 2034. A torsional compression spring 2033 is sleeved on each connecting screw 2032, and the torsional compression spring 2033 is compressed between the push plate 2031 and the limit plate 2034. The rear end of the push plate 2031 abuts against the lower front end of the connecting plate 201. The design of the torsional stiffness simulation spring assembly 203 is based on the lever principle to convert torsional stiffness into linear stiffness, further reducing the test difficulty of the entire equivalent simulation device.

[0062] See Figure 1 and Figure 5 , a plurality of bolt holes are provided on the connecting plate 201 and are connected to the frame 103 through a plurality of bolts. The upper end of the frame 103 is connected to the connecting plate 201 in the bending stiffness simulation device 2 in the upper row, and the lower end is connected to the connecting plate 201 in the bending stiffness simulation device 2 in the lower row, so that the local wall panel test piece 1 is connected to the boundary stiffness equivalent simulation device.

[0063] As a preferred solution, each frame 103 is connected to a corresponding bending stiffness simulation device 2.

[0064] See Figure 5 and Figure 7 , the connecting plate 201 is divided into a rotation connecting part 2011 and a support connecting part 2012 which are integrally connected. The rotation connecting part 2011 is connected to the rotating shaft 202. The width of the rotation connecting part 2011 is greater than the width of the support connecting part 2012. From the support connecting part 2012 to the rotation connecting part 2011, the width of the entire connecting plate 201 gradually increases. The setting of this structure can enhance the connection strength between the entire connecting plate 201 and the rotating shaft 202. The bottom of the rotation connecting part 2011 extends into the rear end of the push plate 2031, and the front end of the rotation connecting part 2011 abuts against the rear end of the push plate 2031. The support connecting part 2012 is provided with a plurality of bolt holes for bolt connection with the frame 103.

[0065] As a preferred solution, the support connecting part 2012 is arc-shaped, and the arc is the same as that of the frame 103. Since the support connecting part 2012 and the frame 103 have a large area of connection and the same arc is set, the connection strength between the two can be enhanced.

[0066] See 5 and Figure 7, a set of longitudinal stiffness simulation spring assemblies 205 is provided at the lower end of each of the lower row of bending stiffness simulation devices 2, that is, the number of the longitudinal stiffness simulation spring assemblies 205 matches the number of the lower row of bending stiffness simulation devices 2, providing a certain vertical supporting force for the lower row of bending stiffness simulation devices 2 and simulating the longitudinal stiffness at the same time. The longitudinal stiffness simulation spring assembly 205 includes a horizontal support plate 2051, a limit ring 2052 and a longitudinal support spring 2053. The horizontal support plate 2051 is fixedly arranged at the front end of the vertical support plate 301. A plurality of limit rings 2052 are fixedly arranged on the horizontal support plate 2051. The limit rings 2052 are sleeved outside the longitudinal support spring 2053. The limit rings 2052 and the longitudinal support spring 2053 correspond one by one and are coaxial. The upper end of the longitudinal support spring 2053 is connected to the horizontal fixing plate 209, and the lower end is connected to the horizontal support plate 2051. When the longitudinal support spring 2053 is compressed, the limit ring 2052 can prevent the longitudinal support spring 2053 from deviating from the vertical direction. It should be understood that the height of the limit ring 2052 is lower than the height of the longitudinal support spring 2053, so that the longitudinal support spring 2053 has enough compression space.

[0067] See Figure 1 and Figure 4 , the upper row of bending stiffness simulation devices 2 and the lower row of bending stiffness simulation devices 2 are arranged oppositely, that is, the connecting plate 201 in the upper row of bending stiffness simulation devices 2 is arranged downward, and the connecting plate 201 in the lower row of bending stiffness simulation devices 2 is arranged upward. During the test, a bulkhead 103 is respectively connected to the upper connecting plate 201 and the lower connecting plate 201, and both ends are constrained.

[0068] As a preferred solution, the total number of the upper row of bending stiffness simulation devices 2 and the lower row of bending stiffness simulation devices 2 is not less than 6 sets. Each row is provided with three bending stiffness simulation devices 2, and the upper row of bending stiffness simulation devices 2 and the lower row of bending stiffness simulation devices 2 correspond one by one in the vertical direction.

[0069] The present invention adopts a distributed stiffness simulation method, equivalenting the continuous stiffness boundary to the distributed stiffness simulation applied to the bulkhead 103, ensuring the test accuracy while reducing the loading difficulty.

[0070] The local panel test piece 1 is a part of the fuselage frame, such as Figure 2As shown, in the actual aircraft structure, the local panel test piece 1 is a part of the fuselage frame and is elastically supported by other parts of the fuselage frame. Therefore, fixed boundaries are not adopted for the local panel test piece 1 during the test. During the actual test process, for the convenience of the design of the support device, the boundary stiffness of the local panel test piece 1 is decoupled into three components: torsional stiffness, longitudinal stiffness, and vertical stiffness. Since the lateral stiffness (on both sides) has little influence on the impact response, a free boundary is used for equivalence. In contrast, the vertical stiffness is equivalently simulated by the vertical stiffness simulation spring assembly 302, the longitudinal stiffness is equivalently simulated by the longitudinal stiffness simulation spring assembly 205, and the torsional stiffness is equivalently simulated by the torsional stiffness simulation spring assembly 203. The upper and lower ends of the local panel test piece 1 are connected to the bending stiffness simulation device 2, and its outer surface is subjected to a low-speed impact from ground service equipment.

[0071] The second aspect of the present invention discloses a simulation method based on the above-mentioned boundary stiffness equivalent simulation device for aircraft panel impact tests. The simulation method includes the following steps:

[0072] Step 1: Calculate the longitudinal stiffness value, torsional stiffness value, and vertical stiffness value of the panel boundary stiffness simulation device according to the structural form, dimensions, and material of the fuselage barrel section, as well as the dimensions of the local panel test piece 1 and its position in the frame.

[0073] Step 2: Install the torsional stiffness simulation spring assembly 203, longitudinal stiffness simulation spring assembly 205, and vertical stiffness simulation spring assembly 302 that meet the stiffness requirements according to the longitudinal stiffness value, torsional stiffness value, and vertical stiffness value.

[0074] Step 3: Install the local panel test piece 1 on the equivalent simulation device.

[0075] Step 4: Install the soft punch and punch actuator for the impact test, and complete the system debugging of the punch actuator.

[0076] Step 5: Perform small-load actuation loading on the local panel test piece 1, and compare the load-displacement curve of the punch actuator with the simulation results of the barrel section loading.

[0077] Step 6: If the comparison result in Step 5 does not meet the requirements, adjust or replace the longitudinal support spring 2053, torsional compression spring 2033, and vertical compression spring 3022, and re-perform small-load actuation loading until the comparison value between the load-displacement curve of the punch actuator and the simulation results of the barrel section loading is less than the set value.

[0078] Step 7: Start the low-speed impact test of the formal ground service equipment. During the low-speed impact test, the vertical compression stiffness simulation device 3 is subjected to a vertical force. The vertical support plate 301 moves backward under the force, and the vertical compression spring 3022 is compressed to simulate the vertical stiffness. The longitudinal support spring 2053 is subjected to the downward pressure of the bending stiffness simulation device, and the longitudinal support spring 2053 is compressed. When it is compressed to the limit or the horizontal fixing plate 209 contacts the limit ring 2052, the compression limit is reached, and the decomposition simulation of the longitudinal stiffness is realized. At the same time, the connecting plate 201 rotates around the rotating shaft 202, and the rotating connection part 2011 moves forward, pushing the push plate 2031 to move forward, and the torsion compression spring 2033 is compressed to realize the decomposition simulation of the torsional stiffness.

[0079] It should be noted that the impact test analysis in the present invention specifically refers to the low-speed impact test analysis. Low-speed impact generally refers to the impact with a speed range of 0 to 5 m / s.

[0080] The overall fuselage barrel section structure is replaced by a local panel structure, and boundary stiffness simulation is adopted to make the simulated boundary stiffness of the local panel structure consistent with the boundary in the real barrel section structure, so as to ensure the consistency of the overall deformation of the local panel structure and the overall barrel section structure. While ensuring the test accuracy, the test cost and the R & D difficulty of the test device are greatly reduced.

[0081] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In the description of the present invention, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them.

[0082] In the description of the present invention, the first feature being "above", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature.

[0083] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0084] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0085] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

[0086] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An equivalent simulation device for the boundary stiffness of an aircraft panel impact test, characterized in that It includes a base (5), and a support platform (4) is arranged on the base (5); The front end of the support platform (4) is connected to a vertical support plate (301) through a plurality of vertical stiffness simulation spring assemblies (302); At the front end of the vertical support plate (301), there are arranged several bending stiffness simulation devices (2) in the upper row and several bending stiffness simulation devices (2) in the lower row which are opposite to each other up and down; several bending stiffness simulation devices (2) in the upper row are fixedly connected to the vertical support plate (301), and several bending stiffness simulation devices (2) in the lower row are slidably connected to the vertical support plate (301); The bending stiffness simulation device (2) includes a longitudinal connecting plate (207) arranged at the front end of the vertical support plate (301). The front end of the longitudinal connecting plate (207) is connected to two longitudinal fixing plates (208). The two longitudinal fixing plates (208) are jointly rotatably connected to a connecting plate (201). The two longitudinal fixing plates (208) are jointly connected to a torsional stiffness simulation spring assembly (203). The front end of the connecting plate (201) abuts against the rear end of the torsional stiffness simulation spring assembly (203); The lower ends of the two longitudinal fixing plates (208) in the bending stiffness simulation device (2) in the lower row are jointly connected to a longitudinal stiffness simulation spring assembly (205), and the longitudinal stiffness simulation spring assembly (205) is arranged on the vertical support plate (301); The connecting plates (201) in the bending stiffness simulation devices (2) in the upper row and the connecting plates (201) in the bending stiffness simulation devices (2) in the lower row are jointly connected to a local wall panel test piece (1); The vertical stiffness simulation spring assembly (302) includes a connecting support column (3021) and a vertical compression spring (3022). The rear end of the connecting support column (3021) is connected to the support platform (4), the front end of the connecting support column (3021) is slidably connected to the vertical support plate (301), and the vertical compression spring (3022) is sleeved on the connecting support column (3021) between the vertical support plate (301) and the support platform (4); The longitudinal stiffness simulation spring assembly (205) includes a horizontal support plate (2051) arranged at the front end of the vertical support plate (301). A limiting ring (2052) is arranged on the horizontal support plate (2051). The limiting ring (2052) is sleeved outside a longitudinal support spring (2053). The upper end of the longitudinal support spring (2053) is connected to a horizontal fixing plate (209), and the lower end of the longitudinal support spring (2053) is connected to the horizontal support plate (2051); The torsional stiffness simulation spring assembly (203) includes two connecting screws (2032). The inner end of each connecting screw (2032) is connected to the U-shaped connecting piece (2010). A push plate (2031) is slidably connected to the two connecting screws (2032) together. The outer ends of the two connecting screws (2032) are jointly connected to a limiting plate (2034). A torsional compression spring (2033) is sleeved on the connecting screw (2032) between the push plate (2031) and the limiting plate (2034). The connecting plate (201) abuts against the rear end of the push plate (2031).

2. The equivalent simulation device for the boundary stiffness of the aircraft panel impact test according to claim 1, wherein Four vertical stiffness simulation spring assemblies (302) are provided, and are respectively arranged at the four top corners of the rear end face of the vertical support plate (301).

3. The equivalent simulation device for the boundary stiffness of the aircraft panel impact test according to claim 1, wherein A longitudinal slider (206) is arranged on the rear end face of the longitudinal connecting plate (207) of the lower row of bending stiffness simulation devices (2). A longitudinal slide rail (204) is arranged at the front end of the vertical support plate (301). The longitudinal slide rail (204) is slidably connected to the longitudinal slider (206).

4. An equivalent simulation device for the boundary stiffness of an aircraft panel impact test according to claim 1, characterized in that The bottom end of the longitudinal fixing plate (208) of the lower row of bending stiffness simulation devices (2) is connected to a horizontal fixing plate (209), and the bottom of the horizontal fixing plate (209) is connected to the longitudinal stiffness simulation spring assembly (205).

5. An equivalent simulation device for the boundary stiffness of an aircraft panel impact test according to claim 1, characterized in that, A rotating shaft (202) is arranged between the protruding parts (2081) of the two longitudinal fixing plates (208). The concave part (2082) of the longitudinal fixing plate (208) is connected to the torsional stiffness simulation spring assembly (203) through the U-shaped connecting piece (2010).

6. The equivalent simulation device for the boundary stiffness of the aircraft panel impact test according to claim 1, characterized in that The connecting plate (201) includes a rotation connecting part (2011) and a support connecting part (2012) which are integrally connected. The width of the rotation connecting part (2011) is greater than the width of the support connecting part (2012). The front end of the rotation connecting part (2011) abuts against the rear end of the torsional stiffness simulation spring assembly (203), and the support connecting part (2012) is connected to the local panel test piece (1).

7. An equivalent simulation method for the boundary stiffness of the aircraft panel impact test based on the simulation device described in claim 1, characterized in that, It includes the following steps: S1. Connect the upper and lower ends of the frame (103) of the local panel test piece (1) to the connecting plates (201) in the two rows of bending stiffness simulation devices (2) respectively. S2. Conduct an impact test on the local panel test piece (1). During the impact test, disperse the vertical stiffness through the vertical stiffness simulation spring assembly (302), disperse the torsional stiffness through the torsional stiffness simulation spring assembly (203), and disperse the longitudinal stiffness through the longitudinal stiffness simulation spring assembly (205).

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