CN109357851B - Four-point bending test loading method for curved frame structure of machine body - Google Patents
Four-point bending test loading method for curved frame structure of machine body Download PDFInfo
- Publication number
- CN109357851B CN109357851B CN201811208788.XA CN201811208788A CN109357851B CN 109357851 B CN109357851 B CN 109357851B CN 201811208788 A CN201811208788 A CN 201811208788A CN 109357851 B CN109357851 B CN 109357851B
- Authority
- CN
- China
- Prior art keywords
- loading
- frame
- test
- fuselage
- supporting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a four-point bending test loading method of a curved frame structure of a machine body, which comprises the following steps of 1: reinforcing the rigidity and the strength of loading sections at two ends of a fuselage bent frame test piece by adopting a reinforcing component; step 2: connecting the loading cushion block and the supporting cushion block; and step 3: the test piece is placed on the test platform, the upper surface of the loading cushion block and the lower surface of the supporting cushion block are both parallel to the test platform and perpendicular to the loading load, the loading load and the supporting load can be guaranteed to be a pair of parallel loads, and therefore pure bending load is formed. The four-point bending test loading device can be used for four-point bending test loading of a curved frame of a fuselage, a wallboard of the fuselage or a similar structure, can effectively prevent the instability, damage or inclination of a loading point part in advance by connecting the reinforcing parts to weak parts such as a frame, a corner piece, a skin and the like at a loading end, realizes pure bending loading and damage in a check section of the wallboard of the fuselage, and provides reliable test basis for the structural design of the curved frame of the fuselage.
Description
Technical Field
The invention relates to the technical field of airplane structure strength tests, in particular to a four-point bending test loading method for a fuselage curved frame structure. The device is used for a four-point bending test of a curved frame, a wall plate or a partition frame structure of a machine body so as to examine the mechanical characteristics of the curved frame or the wall plate structure of the machine body when the curved frame or the wall plate structure of the machine body is subjected to pure bending load.
Background
In the actual use process of the airplane body, the concentrated load of the joint, the airtight load of the airplane body and deformation can generate annular bending moment on the airplane body, and the bending load is jointly borne by the airplane body frame and the skin. In the verification test of the fuselage structure, the loading of the fuselage curved frame structure under the pure bending working condition is very necessary, and the design of the fuselage curved frame structure can be guided and verified. A certain section of the fuselage is intercepted and used as a curved frame structure for test verification, and the structure comprises skin, stringers, frames, corner pieces and other components which are all in curved surface configuration.
The four-point bending loading of the curved frame of the fuselage is a more conventional loading method and aims to examine the mechanical characteristics of the fuselage structure under the pure-bending working condition. However, in a verification test of a curved frame structure of a fuselage, it is obviously impossible to directly use a conventional four-point bending loading method, because parts such as skins, frames, corner pieces and the like are locally weak, and cannot bear concentrated loads during four-point bending loading, local parts are damaged in advance, and the true strength of the structure cannot be verified.
In the conventional verification test, a four-point bending test of a bulkhead without a skin (only comprising a corner piece and a frame) is carried out, but a test piece is locally damaged at a loading point, the bulkhead is inclined, and the bearing capacity of the structure cannot be obtained. When the four-point bending test of the curved frame structure of the fuselage, the technical problem that exists has: local rigidity and strength of corner pieces at the inner edge of a frame and the supporting point at the loading point are weak, stress concentration occurs, the structure is damaged in advance, and the integral bearing capacity cannot be obtained; the rigidity of the frame is weak, the frame can be unstable in advance and even incline when directly bearing concentrated load, and the test cannot continue to load; and thirdly, when the frame inner edge and the skin of the curved frame structure of the fuselage are curved surfaces, the frame inner edge is directly used as a loading surface, and the skin is used as a supporting surface, the loading load is not parallel to the supporting load, so that non-pure bending load is generated.
Disclosure of Invention
Object of the Invention
The invention relates to a four-point bending test loading method for a curved frame structure of a machine body, in particular to a method for reinforcing a loading section of a test piece, bearing concentrated load without damaging the loading section in advance, realizing that an examination section of the test piece bears pure bending load and obtaining the final bearing capacity of the curved frame structure of the machine body.
Technical solution of the invention
In order to achieve the purpose, the invention adopts the following technical scheme:
a four-point bending test loading method of a fuselage curved frame structure comprises the following steps of 1: connecting reinforcing components to loading sections at two ends of a fuselage bent frame test piece so as to enhance the rigidity and strength of the loading sections and prevent local inclination and early damage of loading points; the reinforcing assembly comprises reinforcing frames, a frame edge base plate and a skin base plate, wherein the reinforcing frames are connected to two sides of a frame and a corner piece of the fuselage curved frame test piece; step 2: the surface of the rim backing plate is connected with a wedge-shaped loading cushion block, the surface of the skin backing plate is connected with a wedge-shaped supporting cushion block, and the upper surface of the loading cushion block is parallel to the lower surface of the supporting cushion block; and step 3: the test piece is placed on the test platform, the upper surface of the loading cushion block and the lower surface of the supporting cushion block are both parallel to the test platform and perpendicular to the loading load, the loading load and the supporting load can be guaranteed to be a pair of parallel loads, and therefore pure bending load is formed.
Preferably, the reinforcing frame comprises a C-shaped reinforcing frame, an L-shaped reinforcing frame and an angle-shaped reinforcing frame.
Preferably, the C-shaped reinforcing frame is connected to one side of the corner piece of the test piece, and the frame edge base plate is respectively connected with the upper edge of the C-shaped reinforcing frame and the upper edge of the frame of the test piece; the L-shaped reinforcing frame is connected to the inner side of a web plate of the frame of the test piece; the angle-shaped reinforcing frame is connected between the frame of the test piece and the skin, one side of the angle-shaped reinforcing frame is connected with the angle sheet, and the other side of the angle-shaped reinforcing frame is connected with the skin. The connection modes are all curved surface contact and mechanical connection modes so as to ensure enough connection strength.
Preferably, the inner edge of the C-shaped reinforcing frame is as high as the inner edge of the frame of the test piece.
Preferably, in the step 2, the lower surface of the loading cushion block is in curved surface contact with and fixedly connected with the frame edge cushion plate, the upper surface is a loading surface, and the upper surface is ensured to be horizontal after connection; the upper surface of the supporting cushion block is in contact with and fixedly connected with the curved surface of the skin cushion plate, and the lower surface is a supporting surface and ensures that the lower surface is horizontal after connection. When the loading cushion block and the supporting cushion block are both fixed with the curved frame test piece, and the supporting surface and the loading surface are both horizontal, the supporting load and the loading load can be ensured to be a pair of vertical parallel loads, and a pure bending load is formed. Therefore, the non-pure bending load caused by the fact that the direction of the supporting load is not consistent with that of the loading load when the curved surface is supported and loaded is eliminated.
Preferably, the test platform comprises an upper platform and a lower platform, wherein the two ends of the lower platform are symmetrically provided with supporting seats, and the two ends of the upper platform are symmetrically provided with loading seats.
Preferably, the bottoms of the loading seat and the supporting seat are arc-shaped and symmetrical left and right, and the horizontal distance between the supporting seat and the arc surface vertex of the loading seat which are positioned on the same side of the test platform is a loading force arm L.
THE ADVANTAGES OF THE PRESENT INVENTION
The invention has the advantages that:
the loading surface and the supporting surface are both horizontal surfaces, so that the loading load and the supporting load can be ensured to be a pair of parallel loads, and the pure bending load is formed. The method can avoid the non-pure bending load caused by the inconsistent direction of the supporting load and the loading load when the curved surface of the curved frame test piece is directly supported and loaded. The four-point bending test loading device can be used for four-point bending test loading of a curved frame of a fuselage, a wallboard of the fuselage or a similar structure, can effectively prevent the instability, damage or inclination of a loading point part in advance by connecting the reinforcing parts to weak parts such as a frame, a corner piece, a skin and the like at a loading end, realizes pure bending loading and damage in a check section of the wallboard of the fuselage, and provides reliable test basis for the structural design of the curved frame of the fuselage.
Drawings
Fig. 1 is a front view of the structure and position of each component in the four-point bending test loading method of the fuselage curved frame structure of the invention.
FIG. 2 is a side view of the structure and position of each component in the four-point bending test loading method of the curved frame structure of the fuselage.
Fig. 3 is a sectional view taken along line a-a of fig. 1.
In the drawings: 1-a loading seat; 2, loading a cushion block; 3-a frame edge backing plate; 4-an L-shaped reinforcing frame; 5-frame; 6-angle type reinforcement frame; 7-covering backing plate; 8-a support base; 9-supporting cushion blocks; 10-corner pieces; 11-covering; 12-stringer; 13-C type reinforcing frame.
Detailed Description
Taking the loading of the four-point bending positive bending test of the curved frame of the body as an example, the implementation steps are explained as follows:
the fuselage curved frame test piece mainly comprises a skin 11, corner pieces 10, a frame 5 and stringers 12. The test piece of the curved frame of the machine body is of a bilaterally symmetrical structure, and the left part and the right part of the test piece are connected and installed by all the following components.
Step 1: reinforcing the rigidity and the strength of loading sections at two ends of a fuselage curved frame test piece by adopting a reinforcing component, wherein the reinforcing component comprises reinforcing frames connected to two sides of a frame and a corner piece of the fuselage curved frame test piece, a frame edge base plate connected to the inner edge of the frame and a skin base plate connected to the outer surface of a skin; the reinforcing frame comprises a C-shaped reinforcing frame, an L-shaped reinforcing frame and an angle-shaped reinforcing frame. As shown in fig. 3. The lower surface of the skin 11 is connected with a skin cushion plate 7, the corner piece 10 is connected with a C-shaped reinforcing frame 13, the height of the upper edge of the C-shaped reinforcing frame 13 is equal to that of the upper edge of the frame 5, and two sides of the C-shaped reinforcing frame are tightly attached to the corner piece 10. The frame 5 is connected with the L-shaped reinforcing frame 4, the short edge of the L-shaped reinforcing frame 4 is tightly attached to the upper edge of the frame 5, and the long edge of the L-shaped reinforcing frame 4 is tightly attached to the web plate of the frame 5. The part of the corner piece 10 positioned below the frame 5 is connected with the corner type reinforcing frame 6, one side of the corner type reinforcing frame 6 is connected with the corner piece 10, and the other side is connected with the skin 11. The upper edge of the C-shaped reinforcing frame 13 and the upper edge of the frame 5 are connected with the rim liner plate 3. All the connection modes are mechanical connection so as to ensure enough connection strength.
Step 2: the load and support components are connected. The end parts of two frame edge base plates 3 at two ends of the machine body curved frame test piece are connected with wedge-shaped loading cushion blocks 2, the lower surfaces of the loading cushion blocks 2 are fixedly connected with the frame edge base plates 3, and the upper surfaces of the loading cushion blocks are required to be horizontal after connection. The end parts of the skin backing plates 7 at the two ends of the fuselage curved frame test piece are connected with wedge-shaped supporting cushion blocks 9, the upper surfaces of the supporting cushion blocks 9 are fixedly connected with the skin backing plates 7, and the lower surfaces of the supporting cushion blocks 9 are required to be horizontal after connection.
And step 3: the whole body bent frame test piece which completes the loading and the installation of the supporting part is placed on the supporting seats 8 which are arranged in bilateral symmetry, the bottoms of the supporting seats 8 are in bilateral symmetry arc shapes, the supporting cushion blocks 9 are in contact with the arc surfaces of the supporting seats 8, and the supporting cushion blocks and the supporting seats are in line contact. The loading seat 1 which is arranged in bilateral symmetry applies a load F to the loading cushion block 2, the bottom of the loading seat 1 is in a bilateral symmetry arc shape, the arc surface of the loading seat 1 is in contact with the loading cushion block 2, and the arc surface and the loading cushion block are in line contact. The horizontal distance between the arc surface vertex of the supporting seat 8 positioned on the same side and the arc surface vertex of the loading seat 2 is L, namely the loading force arm, and the bending moment M borne by the machine body bent frame test piece can be calculated according to the formula M which is F.L.
The four-point bending test loading device can be used for four-point bending test loading of a curved frame of a fuselage, a wallboard of the fuselage or a similar structure, can effectively prevent the instability, damage or inclination of a loading point part in advance by connecting the reinforcing parts to weak parts such as a frame, a corner piece, a skin and the like at a loading end, realizes pure bending loading and damage in a check section of the wallboard of the fuselage, and provides reliable test basis for the structural design of the curved frame of the fuselage.
Claims (5)
1. A four-point bending test loading method of a fuselage curved frame structure is characterized by comprising the following steps:
step 1: connecting reinforcing components to loading sections at two ends of a fuselage curved frame test piece, wherein the reinforcing components comprise reinforcing frames at two sides of a frame (5) and a corner piece (10) which are connected to the fuselage curved frame test piece, a frame edge base plate (3) which is connected to the inner edge of the frame (5) and is in a shape matched with that of the inner edge of the frame (5), and a skin base plate (7) which is connected to the outer surface of a skin (11) and is in a shape matched with that of the outer surface of the skin;
step 2: the surface of the rim cushion plate (3) is connected with a wedge-shaped loading cushion block (2), the surface of the skin cushion plate (7) is connected with a wedge-shaped supporting cushion block (9), and the upper surface of the loading cushion block (2) is parallel to the lower surface of the supporting cushion block (9);
and step 3: placing the test piece with the bent frame on a test platform, wherein the upper surface of the loading cushion block (2) and the lower surface of the supporting cushion block (9) are both parallel to the test platform and perpendicular to the loading load, so that the loading load and the supporting load can be guaranteed to be a pair of parallel loads, and a pure bending load is formed;
the reinforcing frame comprises a C-shaped reinforcing frame (13), an L-shaped reinforcing frame (4) and an angle-shaped reinforcing frame (6);
the C-shaped reinforcing frame (13) is connected to one side of the corner piece (10) of the test piece, and the frame edge base plate (3) is respectively connected with the upper edge of the C-shaped reinforcing frame (13) and the upper edge of the frame (5) of the test piece; the L-shaped reinforcing frame (4) is connected to the inner side of a web plate of a frame (5) of the test piece; the angle-shaped reinforcing frame (6) is connected between the frame (5) of the test piece and the skin (11), one side of the angle-shaped reinforcing frame is connected with the angle sheet (10), and the other side of the angle-shaped reinforcing frame is connected with the skin (11).
2. The four-point bending test loading method of the fuselage curved frame structure as claimed in claim 1, characterized in that the inner edge of the C-shaped reinforcing frame (13) is as high as the inner edge of the frame (5) of the test piece.
3. The four-point bending test loading method of the fuselage curved frame structure according to claim 1, characterized in that in step 2, the lower surface of the loading cushion block (2) is in curved surface contact with and fixedly connected with the rim cushion plate (3), the upper surface is a loading surface, and the upper surface is horizontal after connection; the upper surface of the supporting cushion block (9) is in curved surface contact with and fixedly connected with the skin cushion plate (7), and the lower surface is a supporting surface and ensures that the lower surface is horizontal after connection.
4. The four-point bending test loading method of the curved frame structure of the fuselage according to claim 1, characterized in that the test platform comprises an upper platform and a lower platform, the two ends of the lower platform are symmetrically provided with the supporting seats (8), and the two ends of the upper platform are symmetrically provided with the loading seats (1).
5. The four-point bending test loading method of the fuselage curved frame structure according to claim 4, characterized in that the bottoms of the loading seat (1) and the supporting seat (8) are symmetrical circular arcs, and the horizontal distance between the supporting seat (8) and the arc surface vertex of the loading seat (1) on the same side of the test platform is a loading force arm L.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811208788.XA CN109357851B (en) | 2018-10-17 | 2018-10-17 | Four-point bending test loading method for curved frame structure of machine body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811208788.XA CN109357851B (en) | 2018-10-17 | 2018-10-17 | Four-point bending test loading method for curved frame structure of machine body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109357851A CN109357851A (en) | 2019-02-19 |
| CN109357851B true CN109357851B (en) | 2020-08-11 |
Family
ID=65349538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811208788.XA Active CN109357851B (en) | 2018-10-17 | 2018-10-17 | Four-point bending test loading method for curved frame structure of machine body |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109357851B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201069426Y (en) * | 2007-08-01 | 2008-06-04 | 合肥通用机械研究院 | Load device for external bending torque test of three-pass side |
| CN104062107A (en) * | 2014-04-01 | 2014-09-24 | 中国航空工业集团公司沈阳飞机设计研究所 | Static force/fatigue performance test method for single section of reinforced frame/beam |
| CN104777033A (en) * | 2015-03-26 | 2015-07-15 | 西北工业大学 | Four-point bending fatigue test clamp |
| CN106240842A (en) * | 2016-07-11 | 2016-12-21 | 中国飞机强度研究所 | A kind of asymmetric fuselage bulkhead four-point bending test method and device |
-
2018
- 2018-10-17 CN CN201811208788.XA patent/CN109357851B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201069426Y (en) * | 2007-08-01 | 2008-06-04 | 合肥通用机械研究院 | Load device for external bending torque test of three-pass side |
| CN104062107A (en) * | 2014-04-01 | 2014-09-24 | 中国航空工业集团公司沈阳飞机设计研究所 | Static force/fatigue performance test method for single section of reinforced frame/beam |
| CN104777033A (en) * | 2015-03-26 | 2015-07-15 | 西北工业大学 | Four-point bending fatigue test clamp |
| CN106240842A (en) * | 2016-07-11 | 2016-12-21 | 中国飞机强度研究所 | A kind of asymmetric fuselage bulkhead four-point bending test method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109357851A (en) | 2019-02-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109765066B (en) | Medium-low speed maglev vehicle suspension frame strength test platform | |
| CN104097005B (en) | The weld jig of automobile rear seat cushion steel-wire carcass | |
| CN108168854B (en) | Static test fixture for outer cylinder stay bar joint of nose landing gear of airplane | |
| JP6345505B2 (en) | Pressure panel | |
| CN105143084B (en) | Elevator car | |
| CN109357851B (en) | Four-point bending test loading method for curved frame structure of machine body | |
| CN105059297A (en) | Aluminum alloy locomotive traction buffering structure | |
| CN110254748B (en) | Connector-wallboard structure static compression test device | |
| CN106240842B (en) | A kind of asymmetric fuselage bulkhead four-point bending test method and device | |
| CN105651616B (en) | A kind of towing hook strength test device | |
| CN106337894A (en) | Air spring | |
| CN214535443U (en) | Assembled shield constructs quick-witted bracket | |
| CN205707151U (en) | A kind of hull flat segmentation bracing frame | |
| CN214472465U (en) | Fatigue test tool | |
| CN203893835U (en) | An assembling detection apparatus used for suspension split type fork truck canopy guard | |
| CN109336004A (en) | A kind of anti-skid protector suitable for mould handling vehicle | |
| CN207345870U (en) | Vehicle glass turns over shipping unit | |
| CN112427874A (en) | Tool for assembling bogie frame | |
| CN211003540U (en) | Heavy-load strip-shaped plate feeding machine | |
| CN219821195U (en) | Electric automobile | |
| CN220751511U (en) | Split type positioner of airtight detection of car aluminum alloy wheel hub | |
| CN220263075U (en) | Helicopter tail boom damage repair equipment | |
| CN114577430B (en) | Pneumatic load test tool and test method thereof | |
| CN106159155A (en) | Battery module and lifting appliance | |
| CN217058745U (en) | Utensil is examined to commercial car floor welding assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |