Aircraft panel impact test boundary stiffness equivalent simulation method and device

Abstract

The invention discloses an aircraft panel impact test boundary stiffness equivalent simulation method and device, and belongs to the technical field of aircraft ground tests. According to the equivalent simulation device, a local wall plate test piece is adopted to replace an overall fuselage frame to carry out an impact test, a supporting rack is arranged on a base, and a vertical rigidity simulation spring assembly and a bending rigidity simulation device are borne on the basis of the supporting rack; a torsional rigidity simulation spring assembly and a longitudinal rigidity simulation spring assembly are arranged on the bending rigidity simulation device, and a local wallboard test piece is installed on the bending rigidity simulation device. According to the simulation device, the boundary rigidity of the aircraft panel when the aircraft panel is impacted is decomposed into torsional rigidity, vertical rigidity and longitudinal rigidity, so that the boundary rigidity is converted into three groups of linear springs in different directions for rigidity simulation, accurate simulation of the boundary rigidity is ensured, decoupling of boundary rigidity simulation is also realized, and the simulation accuracy is improved. And the design difficulty of the test device is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft ground tests, and in particular relates to a method and a device for simulating boundary stiffness equivalent of an aircraft wall panel impact test. Background Art

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

[0003] In the new generation of aircraft, composite wall panel structures are widely used. Although such structures will not show obvious structural deformation, pits, cracks and other visually visible damage when hit, they may cause serious damage inside the structure. These internal damages may include the destruction of the fuselage frame, debonding of ribs or shear bands, shear failure of bolts and fracture of ribs, etc. These damages will seriously reduce the performance of the aircraft structure and may pose a threat to flight safety.

[0004] In order to ensure the safety of aircraft during service, it is essential to conduct low-speed impact tests on composite structures of aircraft fuselages using ground service equipment. However, existing aircraft impact research focuses on the impact of aircraft landing. For example, the patent application with publication number CN111929019A discloses a ground test device that simulates the impact process of carrier-based aircraft landing gear. The patent application with publication number CN117109861B discloses a patent that simulates the relative movement of wheels and the ground in a laboratory environment and further measures the ground impact load of wheels.

[0005] However, the above-mentioned prior arts lack relevant research on the collision between ground service equipment and aircraft, and it is difficult to estimate the impact of the collision between ground service equipment and aircraft on the aircraft wall panel. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a method and device for simulating the boundary stiffness equivalent of an aircraft wall panel impact test, so as to solve the problem that the prior art lacks ground service equipment and aircraft collision related research, making it difficult to estimate and judge the damage caused to the aircraft wall panel when a related collision occurs.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: An aircraft panel impact test boundary stiffness equivalent simulation device comprises a base, on which a support frame is arranged; The front end of the support frame is connected to a vertical support plate via a plurality of vertical stiffness simulation spring assemblies; The front end of the vertical support plate is provided with a plurality of compression bending stiffness simulation devices in an upper row and a plurality of compression bending stiffness simulation devices in a lower row which are opposite to each other; the plurality of compression bending stiffness simulation devices in the upper row are fixedly connected to the vertical support plate, and the plurality of compression bending stiffness simulation devices in the lower row are slidably connected to the vertical support plate; The bending stiffness simulation device comprises a longitudinal connecting plate arranged at the front end of the vertical supporting plate, the front end of the longitudinal connecting plate is connected to two longitudinal fixing plates, the two longitudinal fixing plates are rotatably connected to the connecting plate together, the two longitudinal fixing plates are commonly connected to a torsional stiffness simulation spring assembly, and the front end of the connecting plate and the rear end of the torsional stiffness simulation spring assembly are against each other; The lower ends of the two longitudinal fixing plates in the lower row of the bending stiffness simulation device are commonly connected with a longitudinal stiffness simulation spring assembly, and the longitudinal stiffness simulation spring assembly is arranged on the vertical support plate; The connecting plates in the upper row of the compression and bending stiffness simulation devices and the connecting plates in the lower row of the compression and bending stiffness simulation devices jointly connect the local wall panel test pieces.

[0008] A further improvement of the present invention is: Preferably, the vertical stiffness simulation spring assembly includes a connecting support column and a vertical compression spring, the rear end of the connecting support column is connected to the support frame, the front end of the connecting support column is slidably connected to 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.

[0009] Preferably, four vertical stiffness simulation spring assemblies are provided, which are respectively arranged at four vertex corners of the rear end surface of the vertical support plate.

[0010] Preferably, a longitudinal slider is provided at the rear end face of the longitudinal connecting plate of the lower row of the compression-bending stiffness simulation device, and a longitudinal slide rail is provided at the front end of the vertical support plate, and the longitudinal slide rail and the longitudinal slider are slidably connected.

[0011] Preferably, the bottom end of the longitudinal fixing plate of the lower row of the bending stiffness simulation device is connected to a horizontal fixing plate, and the bottom of the horizontal fixing plate is connected to the longitudinal stiffness simulation spring assembly.

[0012] Preferably, the longitudinal stiffness simulation spring assembly includes a horizontal support plate arranged at the front end of the vertical support plate, a limiting ring is arranged on the horizontal support plate, the limiting ring is sleeved on the outside of the longitudinal support spring, the upper end of the longitudinal support spring is connected to the horizontal fixed plate, and the lower end of the longitudinal support spring is connected to the horizontal support plate.

[0013] Preferably, a rotation axis is provided between the protruding portions of the two longitudinal fixing plates; and the recessed portions of the longitudinal fixing plates are connected via a U-shaped connecting piece and a torsional stiffness simulation spring assembly.

[0014] Preferably, the torsional stiffness simulation spring assembly includes two connecting screws, the inner end of each connecting screw is connected to a U-shaped connecting piece, the two connecting screws are slidably connected to a push plate, the outer ends of the two connecting screws are connected to a limiting plate, and a torsional compression spring is sleeved on the connecting screw between the push plate and the limiting plate; the rear ends of the connecting plate and the push plate are against each other.

[0015] Preferably, the connecting plate includes a rotating connection part and a supporting connection part which are integrally connected, and the width of the rotating connection part is greater than the width of the supporting connection part; the front end of the rotating connection part and the rear end of the torsional stiffness simulation spring assembly are abutted against each other, and the supporting connection part is connected to the local wall panel test piece.

[0016] An equivalent simulation method for boundary stiffness of an aircraft panel impact test based on the above-mentioned simulation device comprises the following steps: S1, connect the upper and lower ends of the bulkhead of the local wall panel test piece to the connecting plates in the two rows of compression and bending stiffness simulation devices respectively; S2, an impact test is performed on a local wall panel test piece. During the impact test, the vertical stiffness is simulated by simulating the spring assembly to disperse the vertical stiffness, the torsional stiffness is simulated by simulating the spring assembly to disperse the torsional stiffness, and the longitudinal stiffness is simulated by simulating the spring assembly to disperse the longitudinal stiffness.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses an equivalent simulation device for boundary stiffness of impact test of aircraft wall panel. The equivalent simulation device is provided with a support stand on a base, based on the support stand, connected with a bending stiffness simulation device through a vertical stiffness simulation spring assembly in front of the support stand, and a torsional stiffness simulation spring assembly and a longitudinal stiffness simulation spring assembly are provided on the bending stiffness simulation device, and the boundary stiffness of the aircraft wall panel when impacted is decomposed into torsional stiffness, vertical stiffness and longitudinal stiffness, and the decomposed three stiffnesses are converted into three groups of linear springs in different directions for stiffness simulation, and the method ignores the influence of lateral stiffness, ensures accurate simulation of boundary stiffness, and also realizes decoupling of boundary stiffness simulation, thereby reducing the design difficulty of the test device. During the test, a test piece in the form of a local wall panel is used to replace the overall fuselage frame, and the scene of accidental collision of airport ground equipment with the aircraft fuselage structure is simulated in a laboratory environment, so that the deformation mode and failure behavior of the test piece in the form of the local wall panel are consistent with those of the overall fuselage barrel section, and the consistency of boundary stiffness is ensured, thereby ensuring that the impact resistance characteristics of the fuselage composite material structure are true and reliable, and the test cost and test difficulty can be significantly reduced.

[0018] Furthermore, the vertical stiffness simulation spring assembly is stressed by the compressed vertical compression spring, so that when the entire vertical support plate is subjected to impact force, the vertical stiffness can be simulated.

[0019] Furthermore, 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 impact force, the entire vertical support plate is subjected to uniform force.

[0020] Furthermore, the longitudinal connecting plate in the lower row of the bending stiffness simulation device cooperates with the longitudinal slider and the longitudinal slide rail, so that when the local wall panel test piece is deformed due to impact force, the lower row of the bending stiffness simulation device can be pushed to move downward.

[0021] Furthermore, the bottom end of the longitudinal fixed plate is connected to the longitudinal stiffness simulation spring assembly through the horizontal fixed plate, and the connecting plate is connected to the local wall panel test piece, so that when the local wall 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.

[0022] Furthermore, the longitudinal stiffness simulation spring assembly includes a longitudinal support spring and a limiting ring mounted 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 provide a certain buffer to the bending stiffness simulation device.

[0023] Furthermore, two longitudinal fixing plates are provided, and a rotating shaft is provided between the two longitudinal fixing plates. The connection between the rotating shaft and the connecting plate is realized through the rotation connection between the rotating shaft and the connecting plate, so as to realize the connection between the local wall panel test piece and the equivalent simulation device.

[0024] Furthermore, the torsional stiffness simulation spring assembly is configured with a push plate and a limit plate, and a torsional compression spring is configured between the push plate and the limit plate, so that when the connecting plate is deformed by an external force, the bottom of the connecting plate pushes the push plate forward to achieve the transmission of the torsional force. The torsional stiffness simulation spring assembly can simulate the dispersed torsional stiffness.

[0025] Furthermore, the structure of the connecting plate is that the rotating connecting portion is wide and the supporting connecting portion is narrow, so as to enhance the connection strength of the entire connecting plate, and at the same time, the wider rotating connecting portion can better disperse the torsional stiffness.

[0026] The present invention also discloses an equivalent simulation method for boundary stiffness of aircraft wall panel impact test, in which the upper and lower ends of the bulkhead of the local wall panel test piece are respectively connected to the connecting plates, so that the local wall panel test piece is installed on the entire equivalent simulation device for simulation test. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of the boundary stiffness simulation device of the present invention; Figure 2 It is a side view of the three-dimensional structure of the boundary stiffness simulation device of the present invention; Figure 3 It is a structural schematic diagram of the support frame and the base of the present invention; Figure 4 A three-dimensional structural detail diagram of the boundary stiffness simulation device of the present invention; Figure 5 For the present invention Figure 4 Enlarged view of area A in the middle; Figure 6 For the present invention Figure 4 Enlarged view of area B in the middle; Figure 7 It is a schematic structural diagram of the torsional stiffness simulation spring assembly and the longitudinal stiffness simulation spring assembly of the present invention.

[0028] Among them: 1. Local wall panel test piece; 2. Bending stiffness simulation device; 3. Vertical compression stiffness simulation device; 4. Support stand; 5. Base; 101. Skin; 102. Long girder; 103. Bulkhead; 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 connector; 2011, rotating connection; 2012, supporting connection; 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, recess; 3011, observation plate; 3021, connecting support column; 3022, vertical compression spring. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings: Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout 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 are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] See also Figure 1 and Figure 5 In the first aspect, the present invention discloses a boundary stiffness equivalent simulation device for an aircraft wall panel impact test, 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; wherein 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, which is used as a reference direction, and will not be repeated later. 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.

[0031] See also Figure 1 and Figure 2During the test, the local panel test specimen 1 of the aircraft is installed in front of the vertical compression stiffness simulation device 3 and connected to the bending stiffness simulation device 2. The local panel test specimen 1 includes a skin 101, a long stringer 102 and a bulkhead 103. The long stringer 102 is arranged along the axial direction of the entire fuselage, and the bulkhead 103 is arranged along the circumferential direction of the entire fuselage. The long stringer 102 and the bulkhead 103 are connected by a shear band, and the long stringer 102 is perpendicular to the plane where the bulkhead 103 is located. Figure 2 The vertical arc in the partial wall panel test piece 1 shown in the figure is the bulkhead 103 , the transverse arc is the long stringer 102 , and the skin 101 is arranged on the outside of the long stringer 102 and the bulkhead 103 .

[0032] The present invention defines the direction perpendicular to the center of the outer surface of the local wall panel test piece 1 and pointing to the center point of the local wall panel test piece 1 as the vertical direction, that is, the impact direction of the ground service equipment, which is the horizontal direction; defines the direction passing through the impact point and tangent to the bulkhead 103 as the longitudinal direction, which is the vertical direction; defines the direction along the long stringer 102 as the transverse direction, that is, the axial direction or heading of the aircraft, which is the horizontal direction.

[0033] See also Figure 2 and Figure 3 The base 5 is set at the bottom. During the test, the base 5 is fixed on the ground. The support frame 4 is fixed on the base 5 by multiple fixing bolts. The support frame 4 is a frame structure welded from square steel. Multiple support frames are arranged inside. Some of the support frames are inserted into the inside of the base 5 and fixedly connected with the inside of the base 5 by bolts to enhance the connection force between the support frame 4 and the base 5.

[0034] Furthermore, a horizontal transverse plate is provided at the middle position of the support frame 4 to enhance the supporting capacity of the entire support frame 4 .

[0035] See also Figure 4In 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. 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 connecting support column 3021 and a vertical compression spring 3022 arranged in a horizontal direction. 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 limiting block is arranged at the front end of the connecting support column 3021. The limiting block is at the front end of the vertical support plate 301. The area of ​​the limiting block is larger than the area of ​​the hole opened on the vertical support plate 301 through which the connecting support column 3021 passes, so as to prevent the vertical support plate 301 from slipping off the connecting support column 3021. A vertical compression spring 3022 is mounted on the connecting support column 3021 between the vertical support plate 301 and the support stand 4 . The rear end of the vertical compression spring 3022 is fixedly connected to the front end of the support stand 4 , and the front end is a free end that abuts against the vertical support plate 301 .

[0036] As a preferred solution, four vertical stiffness simulation spring components 302 are respectively arranged at the four corners of the vertical support plate 301, so that the support stand 4 is subjected to uniform force during the impact test.

[0037] See also 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. Each row is provided with a plurality of bending stiffness simulation devices 2, 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 are fixedly connected to the vertical support plate 301, and the lower row of bending stiffness simulation devices 2 are slidably connected to the vertical support plate 301.

[0038] See also Figure 4 As a preferred solution, an observation plate 3011 is provided on the vertical support plate 301. The observation plate 3011 is made of a transparent acrylic material, which is convenient for observing the deformation of the local wall panel test piece 1 during the impact process.

[0039] In some specific embodiments of the present invention, the support stand 4 is a frame structure and an observation plate 3011 is provided on the vertical support plate 301 to facilitate observation of the deformation of the local wall panel test piece 1 from the rear side of the support stand 4 .

[0040] See also Figure 5 , Figure 6 and Figure 7Each 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 .

[0041] See also Figure 5 , Figure 6 and Figure 7 The longitudinal connecting plate 207 and the vertical supporting plate 301 are parallel. The longitudinal connecting plate 207 and the vertical supporting plate 301 in the upper row of the bending stiffness simulation device 2 are fixedly connected by bolts, and the longitudinal connecting plate 207 and the vertical supporting plate 301 in the lower row of the bending stiffness simulation device 2 are slidingly connected. The front end of each longitudinal connecting plate 207 is fixedly connected to two longitudinal fixing plates 208 and a horizontal fixing plate 209, and the lower ends of the two longitudinal fixing plates 208 are connected to the horizontal fixing plate 209. The longitudinal connecting plates 207, the longitudinal fixing plates 208 and the horizontal fixing plates 209 are perpendicular to each other.

[0042] See also Figure 5 , Figure 6 and Figure 7 The longitudinal fixing plate 208 is divided into a protruding portion 2081 and a recessed portion 2082 which are connected in one piece. The protruding portion 2081 is on the upper side of the recessed portion 2082. The width of the protruding portion 2081 is greater than that of the recessed portion 2082, that is, the protruding portion 2081 protrudes further forward than the recessed portion 2082. A rotating shaft 202 is fixedly connected between the two protruding portions 2081, and a connecting plate 201 is rotatably connected to the rotating shaft 202. The recessed portion 2082 is connected to a U-shaped connecting piece 2010 by bolts. Both sides of each U-shaped connecting piece 2010 are connected to the recessed portion 2082 by bolts. A torsional stiffness simulating spring assembly 203 is connected to the middle part of each U-shaped connecting piece 2010.

[0043] See also Figure 5 The rear end of the longitudinal connecting plate 207 in the lower row of the bending stiffness simulation device 2 is fixedly connected to 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 are slidably connected to a longitudinal slide rail 204. Each longitudinal slide rail 204 is fixedly set on the vertical support plate 301.

[0044] See also Figure 5 , Figure 6 and Figure 7The 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 connector 2010, and the front ends of the two connecting screws 2032 are 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 and the front end of the lower part of the connecting plate 201 are against each other. The design of the torsional stiffness simulation spring assembly 203 is based on the lever principle to convert torsional stiffness into linear stiffness, which further reduces the test difficulty of the entire equivalent simulation device.

[0045] See also Figure 1 and Figure 5 A plurality of bolt holes are provided on the connecting plate 201, which is connected to the bulkhead 103 by a plurality of bolts. The upper end of the bulkhead 103 is connected to the connecting plate 201 in the upper row of the compression and bending stiffness simulation device 2, and the lower end is connected to the connecting plate 201 in the lower row of the compression and bending stiffness simulation device 2, so that the local wall panel test piece 1 is connected to the boundary stiffness equivalent simulation device.

[0046] As a preferred solution, each bulkhead 103 is connected with a corresponding compression-bending stiffness simulation device 2 .

[0047] See also Figure 5 and Figure 7 The connecting plate 201 is divided into a rotating connecting part 2011 and a supporting connecting part 2012 which are connected in one piece. The rotating connecting part 2011 is connected to the rotating shaft 202. The width of the rotating connecting part 2011 is greater than the width of the supporting connecting part 2012. From the supporting connecting part 2012 to the rotating 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 rotating connecting part 2011 extends into the rear end of the pushing plate 2031, and the front end of the rotating connecting part 2011 and the rear end of the pushing plate 2031 are against each other. The supporting connecting part 2012 is provided with a plurality of bolt holes for bolting with the bulkhead 103.

[0048] As a preferred solution, the support connection part 2012 is arc-shaped, and the curvature is the same as the curvature of the bulkhead 103. Since the support connection part 2012 and the bulkhead 103 are connected over a large area, the same curvature is set in combination, which can enhance the connection strength between the two.

[0049] See 5 and Figure 7A set of longitudinal stiffness simulation spring components 205 is arranged at the lower end of each lower row of bending stiffness simulation devices 2, that is, the number of longitudinal stiffness simulation spring components 205 matches the number of lower row of bending stiffness simulation devices 2, providing a certain vertical support force for the lower row of bending stiffness simulation devices 2 and simulating longitudinal stiffness at the same time. The longitudinal stiffness simulation spring components 205 include 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, and a plurality of limiting rings 2052 are fixedly arranged on the horizontal support plate 2051. The limiting rings 2052 are sleeved outside the longitudinal support spring 2053. The limiting rings 2052 and the longitudinal support spring 2053 correspond to each other and are coaxial. The upper end of the longitudinal support spring 2053 is connected to the horizontal fixed plate 209, and the lower end is connected to the horizontal support plate 2051. When the longitudinal support spring 2053 is compressed, the limiting ring 2052 can prevent the longitudinal support spring 2053 from deviating from the vertical direction. It should be understood that the height of the limiting ring 2052 is lower than the height of the longitudinal support spring 2053, so that the longitudinal support spring 2053 has enough compression space.

[0050] See also Figure 1 and Figure 4 The upper row of compression bending stiffness simulation devices 2 and the lower row of compression bending stiffness simulation devices 2 are arranged opposite to each other, that is, the connection plates 201 in the upper row of compression bending stiffness simulation devices 2 are arranged downward, and the connection plates 201 in the lower row of compression bending stiffness simulation devices 2 are arranged upward. During the test, a bulkhead 103 is connected to the upper connection plate 201 and the lower connection plate 201, respectively, and both ends are constrained.

[0051] As a preferred solution, the total number of the bending stiffness simulation devices 2 in the upper row and the bending stiffness simulation devices 2 in the lower row is not less than 6 sets, each row is provided with three bending stiffness simulation devices 2, and the bending stiffness simulation devices 2 in the upper row and the bending stiffness simulation devices 2 in the lower row correspond one to one in the vertical direction.

[0052] The present invention adopts a distributed stiffness simulation method, and equates the continuous stiffness boundary to a distributed stiffness simulation applied to the bulkhead 103, thereby ensuring the test accuracy and reducing the difficulty of loading.

[0053] 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, during the test, no fixed boundary is used for the local panel test piece 1. In the actual test process, in order to facilitate 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 (both sides) has little effect on the impact response, the free boundary equivalence is adopted. 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 the low-speed impact of the ground service equipment.

[0054] The second aspect of the present invention discloses a simulation method based on the above-mentioned aircraft panel impact test boundary stiffness equivalent simulation device, and the simulation method comprises the following steps: Step 1, according to the fuselage barrel section structure, size and material, as well as the size and position of the local panel test piece 1 on the frame, calculate the longitudinal stiffness value, torsional stiffness value and vertical stiffness value of the panel boundary stiffness simulation device; Step 2, according to the longitudinal stiffness value, the torsional stiffness value and the vertical stiffness value, install the torsional stiffness simulation spring assembly 203, the longitudinal stiffness simulation spring assembly 205 and the vertical stiffness simulation spring assembly 302 that meet the stiffness requirements; Step 3, installing the local wall panel test piece 1 on the equivalent simulation device; Step 4, installing the soft punch and punch actuator for the impact test, and completing the system debugging of the punch actuator; Step 5, performing a small load actuation loading on the local wall panel test piece 1, and comparing the load displacement curve of the punch actuator with the simulation result of the barrel section loading; Step 6: If the comparison result in step 5 does not meet the requirements, adjust or replace the longitudinal support spring 2053, the torsion compression spring 2033 and the vertical compression spring 3022, and re-load with a small load until the comparison value between the load displacement curve of the punch actuator and the simulation result of the barrel loading is less than the set value; Step 7, start the formal low-speed impact test of the 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 is forced to move backward, and the vertical compression spring 3022 is compressed to realize the simulation of 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 fixed plate 209 and the limit ring 2052 are in contact, 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 connecting part 2011 moves forward, pushing the push plate 2031 to move forward, and the torsional compression spring 2033 is compressed to realize the decomposition simulation of the torsional stiffness.

[0055] It should be noted that the impact test analysis in the present invention specifically refers to low-speed impact test analysis, and low-speed impact generally refers to impact with a speed range of 0-5 m / s.

[0056] A local wall panel structure is used to replace the overall fuselage barrel section structure, and boundary stiffness simulation is used to ensure that the simulated boundary stiffness of the local wall panel structure is consistent with the boundary in the actual barrel section structure, thereby ensuring the consistency of the overall deformation of the local wall panel structure with the overall barrel section structure. While ensuring the test accuracy, the test cost and the difficulty of developing the test equipment are greatly reduced.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are 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 on the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, the first feature "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact but being in contact through another feature between them.

[0058] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An equivalent simulation device for boundary stiffness of aircraft panel impact test, characterized in that: It comprises a base (5), on which a supporting frame (4) is arranged; The front end of the support frame (4) is connected to a vertical support plate (301) via a plurality of vertical stiffness simulation spring assemblies (302); The front end of the vertical support plate (301) is provided with a plurality of compression bending stiffness simulation devices (2) in an upper row and a plurality of compression bending stiffness simulation devices (2) in a lower row, which are opposed to each other in an upper and lower direction; the plurality of compression bending stiffness simulation devices (2) in the upper row are fixedly connected to the vertical support plate (301), and the plurality of compression bending stiffness simulation devices (2) in the lower row are slidably connected to the vertical support plate (301); The compression bending stiffness simulation device (2) comprises 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) being connected to two longitudinal fixing plates (208), the two longitudinal fixing plates (208) being rotatably connected to the connecting plate (201), the two longitudinal fixing plates (208) being connected to a torsional stiffness simulation spring assembly (203), the front end of the connecting plate (201) and the rear end of the torsional stiffness simulation spring assembly (203) being abutted against each other; The lower ends of the two longitudinal fixing plates (208) in the lower row of the compression bending stiffness simulation device (2) are commonly 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 plate (201) in the upper row of the compression and bending stiffness simulation device (2) and the connecting plate (201) in the lower row of the compression and bending stiffness simulation device (2) are connected together to the local wall panel test piece (1).

2. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: The vertical stiffness simulation spring assembly (302) comprises 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 stand (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 stand (4).

3. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: Four vertical stiffness simulation spring assemblies (302) are provided, and are respectively arranged at four top corners of the rear end surface of the vertical support plate (301).

4. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: A longitudinal slide block (206) is provided at the rear end surface of the longitudinal connection plate (207) of the lower row of compression bending stiffness simulation devices (2), and a longitudinal slide rail (204) is provided at the front end of the vertical support plate (301), and the longitudinal slide rail (204) and the longitudinal slide block (206) are slidably connected.

5. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: The bottom end of the longitudinal fixing plate (208) of the lower row of the compression bending stiffness simulation device (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).

6. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 5, characterized in that: The longitudinal stiffness simulation spring assembly (205) comprises a horizontal support plate (2051) arranged at the front end of the vertical support plate (301), a limit ring (2052) being arranged on the horizontal support plate (2051), the limit ring (2052) being sleeved on the outside of the longitudinal support spring (2053), the upper end of the longitudinal support spring (2053) being connected to the horizontal fixing plate (209), and the lower end of the longitudinal support spring (2053) being connected to the horizontal support plate (2051).

7. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: A rotating shaft (202) is provided between the protruding portions (2081) of the two longitudinal fixing plates (208); the recessed portions (2082) of the longitudinal fixing plates (208) are connected via a U-shaped connecting piece (2010) and a torsional stiffness simulation spring assembly (203).

8. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 7, characterized in that: The torsional stiffness simulation spring assembly (203) comprises two connecting screws (2032), the inner end of each connecting screw (2032) being connected to a U-shaped connecting piece (2010), the two connecting screws (2032) being slidably connected to a push plate (2031), the outer ends of the two connecting screws (2032) being connected to a limit plate (2034), and a torsional compression spring (2033) being sleeved on the connecting screw (2032) between the push plate (2031) and the limit plate (2034); the rear ends of the connecting plate (201) and the push plate (2031) are against each other.

9. The aircraft panel impact test boundary stiffness equivalent simulation device according to claim 1, characterized in that: The connecting plate (201) comprises a rotating connecting portion (2011) and a supporting connecting portion (2012) connected in one piece, the width of the rotating connecting portion (2011) being greater than the width of the supporting connecting portion (2012); the front end of the rotating connecting portion (2011) and the rear end of the torsional stiffness simulation spring assembly (203) are against each other, and the supporting connecting portion (2012) is connected to a local wall panel test piece (1).

10. A method for simulating the boundary stiffness equivalent of an aircraft panel impact test based on the simulation device of claim 1, characterized in that: The following steps are involved: S1, connecting the upper and lower ends of the bulkhead (103) of the local wall panel test piece (1) to the connecting plates (201) in two rows of the compression bending stiffness simulation device (2); S2, an impact test is performed on the local wall panel test piece (1). During the impact test, the vertical stiffness is dispersed by the vertical stiffness simulation spring assembly (302), the torsional stiffness is dispersed by the torsional stiffness simulation spring assembly (203), and the longitudinal stiffness is dispersed by the longitudinal stiffness simulation spring assembly (205).

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