Universal clamp for low-speed impact test of foam buffer composite laminate
By designing a general fixture including a test bench, support column, pad plate and foam buffer block, the problem that the low-speed impact test fixture of composite laminated plates in the prior art cannot simulate the foam filling buffering effect, and the adaptability to samples of different sizes and the accuracy of experimental results are achieved.
Patent Information
- Application Number
- CN202421084964.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-05-17
AI Technical Summary
The existing low-speed impact test fixtures of composite laminates cannot effectively simulate the buffering effect of foam filling inside the skin structure of composite materials, resulting in a large deviation from the actual situation. The fixtures have fixed requirements for the size of the sample and cannot adapt to samples of different sizes.
A universal fixture was designed, including a laboratory bench, support column, pad plate and foam buffer block. Through the cooperation of rectangular positioning holes and rectangular foam buffer blocks, the buffer medium inside the skin structure of the composite material is simulated to achieve adaptability to samples of different sizes.
The fixture can maintain the stability of the specimens during the experiment, simulate a real low-speed impact environment, reduce the deviation of the experimental results, and adapt to samples of different sizes, improving the accuracy and flexibility of the experiment.
Smart Images
Figure CN222689539U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of experimental testing equipment, in particular to a universal clamp used for low-speed impact testing of foam buffer composite material laminates. Background Art
[0002] Composite skin structures are susceptible to low-speed impact loads during service, which reduces their residual strength and fatigue life, posing a potential threat to service safety. The actual composite skin structure is usually composed of composite laminates on the outer surface and special foam fillings inside. The foam filler acts as a buffer block to reduce the low-speed impact of the composite laminates on the outer surface. Therefore, in order to truly simulate the actual service loading conditions, it is necessary to conduct a low-speed impact test on the composite laminate with foam filling at the bottom, and the experimental fixture is a key link. At present, the bottom of the low-speed impact test fixture of composite laminates at home and abroad is usually a circular or rectangular opening, which cannot simulate the buffering effect of the foam filling inside the actual composite skin structure, resulting in a large deviation between the laboratory experimental results and the actual composite skin under the actual impact load. In addition, the existing fixtures have fixed requirements for the size of the specimens and cannot adapt to the changes in the size of the specimens in the actual composite skin structure.
[0003] Therefore, it is necessary to develop a universal fixture for low-speed impact testing of foam-cushioned composite laminates to solve the above problems. Utility Model Content
[0004] The utility model aims to solve the above problems and designs a universal fixture for low-speed impact test of foam cushioning composite material laminates.
[0005] The utility model achieves the above-mentioned purpose through the following technical solutions:
[0006] A universal fixture for low velocity impact testing of foam cushion composite laminates, comprising:
[0007] Experimental table; a rectangular positioning hole is provided in the middle of the experimental table; the sample is placed on the surface of the experimental table, and the center of the sample is aligned with the center of the rectangular positioning hole;
[0008] A plurality of support columns; a first end of the support column is connected to the test bench, and a second end of the support column is connected to the test machine;
[0009] A pad; a third through hole is provided at the center of the pad, the pad is mounted on the lower surface of the experimental table, and the third through hole is aligned with the center of the rectangular positioning hole;
[0010] The foam buffer block is formed into a rectangular parallelepiped, the length and width of the foam buffer block are slightly smaller than the length and width of the rectangular positioning hole, the height of the foam buffer block is equal to the height of the rectangular positioning hole, the foam buffer block is installed in the rectangular positioning hole, and is placed on the pad.
[0011] The beneficial effects of the utility model are:
[0012] 1. The test bench with rectangular through holes is rigidly connected to the drop weight impact test machine through a support column to ensure that the test bench will not be displaced or shaken due to the vibration caused by the impact during the experiment, so that the specimen has good stability during the impact process;
[0013] 2. The bottom pad is connected to the test bench and placed on the lower surface of the test bench, which can provide a certain support to the buffer block so that the buffer block remains in the rectangular through hole during the impact process without falling;
[0014] 3. The buffer block is placed in the rectangular through hole of the test bench, and the lower end is provided with an upward support force by a pad with a through hole. The buffer block can simulate the effect of the buffer medium filling inside the real composite skin structure, and can be used in conjunction with the impact hammer to carry out low-speed impact tests;
[0015] 4. The test bench achieves the purpose of low-speed impact test of foam cushioning composite material laminates through sophisticated coordination and connection with the pad, and can simulate the real low-speed impact environment simply, practically, accurately and realistically. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the structure of the experimental platform in this application;
[0017] Figure 2 This is a schematic diagram of the structure of the pad in this application;
[0018] Figure 3 This is a schematic diagram of the structure of the foam buffer block in this application;
[0019] Figure 4 This is a schematic diagram of the structure of the positioning pin in this application;
[0020] Figure 5 This is a schematic diagram of the structure of the support column in this application;
[0021] Figure 6 This is a schematic diagram of the structure of this application;
[0022] Figure 7 This is a schematic diagram of the scale on the laboratory bench in this application;
[0023] Figure 8 for Figure 7 A magnified schematic diagram of part A in FIG.
[0024] In the figure: 1-laboratory table; 11-rectangular positioning hole; 12-vertical slide groove; 13-horizontal slide groove; 14-first through hole; 15-second through hole; 16-scale; 2-pad; 21-third through hole; 22-fourth through hole; 3-foam buffer block; 4-locating pin; 5-support column; 51-rod; 52-flange; 53-screw hole; 6-first bolt; 7-second bolt. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0028] In the description of the present utility model, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the utility model product is usually placed when in use, or are directions or positional relationships that are usually understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present utility model.
[0029] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.
[0030] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" 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 an indirect connection 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.
[0031] The specific implementation of the utility model is described in detail below in conjunction with the accompanying drawings.
[0032] like Figure 1-6 A universal fixture for low-speed impact testing of foam cushion composite laminates is shown, comprising:
[0033] The test bench 1; a rectangular positioning hole 11 is provided in the middle of the test bench 1; the sample is placed on the upper surface of the test bench 1, and the center of the sample is aligned with the center of the rectangular positioning hole 11;
[0034] Four support columns 5; the four support columns 5 are arranged on the lower surface of the experimental table 1; the support column 5 includes a rod portion 51 and a flange portion 52, the first end of the rod portion 51 is connected to the center of the flange portion 52, the second end of the rod portion 51 is connected to the experimental machine, four screw holes are evenly arranged on the flange portion 52, and four first through holes 14 are correspondingly arranged at each corner of the rectangular experimental table 1, and the second bolt 7 passes through the first through hole 14 and then is screwed into the screw hole 53 on the flange portion 52 to complete the connection between the flange portion 52 and the experimental table 1; in some embodiments, the screw hole 53 on the flange portion 52 can be a through hole, the first bolt 6 passes through the first through hole 14, and then passes through the through hole on the flange portion 52 and is then locked by a nut, so that the installation of the pad 2 can be completed;
[0035] The backing plate 2; a third through hole 21 is provided at the center of the backing plate 2, and the third through hole 21 is aligned with the center of the rectangular positioning hole 11; the backing plate 2 forms a rectangle, and each corner of the backing plate 2 is provided with two fourth through holes 22, and correspondingly, eight second through holes 15 are also provided on the experimental table 1, and the first bolt 6 passes through the second through hole 15, and then passes through the fourth through hole 22 and is locked with a nut, so that the backing plate 2 is installed on the lower surface of the experimental table 1; in some embodiments, the fourth through hole 22 can be a screw hole, and the first bolt 6 passes through the second through hole 15 and is screwed into the fourth through hole 22 to complete the installation of the backing plate 2;
[0036] The foam buffer block 3 (the foam buffer block 3 of different materials can be replaced according to the experiment); the foam buffer block 3 is formed into a rectangular parallelepiped, the length and width of the foam buffer block 3 are slightly smaller than the length and width of the rectangular positioning hole 11, the height of the foam buffer block 3 is equal to the height of the rectangular positioning hole 11, (the foam buffer block 3 is not easy to fall off after being installed in the rectangular positioning hole 11), the foam buffer block 3 is installed in the rectangular positioning hole 11, and is placed on the pad 2. In some embodiments, the size of the foam buffer block 3 can be slightly larger than the rectangular positioning hole 11, and the foam buffer block 3 and the rectangular positioning hole 11 are interference fit.
[0037] Four positioning pins 4; on the test bench 1, two transverse grooves 13 (one at each end) are arranged outside the two ends of the long side of the rectangular positioning hole 11, and the transverse grooves 13 are perpendicular to the long side of the rectangular positioning hole 11; two vertical grooves 12 (one at each end) are arranged outside the two ends of the wide side of the rectangular positioning hole 11, and the vertical grooves 12 are perpendicular to the wide side of the rectangular positioning hole 11; after the center of the specimen is aligned with the center of the rectangular positioning hole 11, the positioning pins 4 are respectively interference fit with the transverse grooves 13 and the vertical grooves 12, The wide side of the sample contacts the positioning pin 4 in the horizontal slide groove 13, and the long side of the sample contacts the positioning pin 4 in the vertical slide groove 12; scales 16 are provided on one side of the horizontal slide groove 13 and one side of the vertical slide groove 12, and the starting value of the scale 16 on one side of the horizontal slide groove 13 is the shortest distance between the horizontal slide groove 13 and the central section of the wide side of the rectangular positioning hole 11, and the starting value of the scale 16 on one side of the vertical slide groove 12 is the shortest distance between the vertical slide groove 12 and the central section of the long side of the rectangular positioning hole 11.
[0038] In the present application, the positioning pin 4 is placed in a slide groove above the test bench 1 with a rectangular through hole, which is used to position the sample and can be flexibly adjusted according to the size of the sample to ensure that the impact hammer can impact the center of the sample during the experiment.
[0039] In the present application, a third through hole 21 is provided at the center of the pad 2 to prevent the impact hammer from directly passing through the pad 2 without causing damage to the pad 2 after the sample is punctured under an overload force, thereby preventing excessive load from causing damage to the bottom pad 2 and the entire experimental device.
[0040] In the present application, since the axis of the impact hammer head is consistent with the axis of the circular through hole at the bottom of the pad 2, as long as the center position of the specimen is determined by the positioning pin, the center of the specimen, the axis of the drop hammer and the center line of the third through hole 21 of the pad 2 are located on the same straight line. This ensures that the impact force applied by the drop hammer during the experiment is located at the center of the specimen.
[0041] like Figure 7 and 8As shown, an embodiment is shown. Among them, the sample is a standard sample (10cm wide × 15cm long), the upper wide side of the sample is aligned with the zero position of the scale 16 on one side of the vertical chute 12 (i.e. 7.5cm), and the right long side of the sample is aligned with the zero position of the scale 16 on one side of the horizontal chute 13 (i.e. 5cm), and then the positioning pin 4 is inserted into the vertical chute 12 and the horizontal chute 13, and is pressed against the sample. When the sample size is 12cm wide × 16cm long (the length and width data of the sample need to be measured before installation and adjustment), the right side of the sample should be aligned with 6cm of the scale 16 on one side of the horizontal chute 13, and the upper side of the sample should be aligned with 8cm of the scale 16 on one side of the vertical chute 12.
[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. A universal fixture for low-speed impact testing of foam cushioning composite laminates, characterized in that: include: Experimental table; a rectangular positioning hole is provided in the middle of the experimental table; the sample is placed on the surface of the experimental table, and the center of the sample is aligned with the center of the rectangular positioning hole; A plurality of support columns; a first end of the support column is connected to the test bench, and a second end of the support column is connected to the test machine; A pad; a third through hole is provided at the center of the pad, the pad is mounted on the lower surface of the experimental table, and the third through hole is aligned with the center of the rectangular positioning hole; The foam buffer block is formed into a rectangular parallelepiped, the length and width of the foam buffer block are slightly smaller than the length and width of the rectangular positioning hole, the height of the foam buffer block is equal to the height of the rectangular positioning hole, the foam buffer block is installed in the rectangular positioning hole, and is placed on the pad.
2. A universal fixture for low-speed impact testing of foam cushioning composite laminates according to claim 1, characterized in that: The universal fixture also includes at least two positioning pins. On the laboratory table, at least one horizontal slide groove is provided on one side of the long side of the rectangular positioning hole, and the horizontal slide groove is perpendicular to the long side of the rectangular positioning hole. At least one vertical slide groove is provided on one side of the wide side of the rectangular positioning hole, and the vertical slide groove is perpendicular to the wide side of the rectangular positioning hole. After the center of the specimen is aligned with the center of the rectangular positioning hole, the positioning pins are respectively interference fit with the horizontal slide groove and the vertical slide groove, the wide side of the specimen contacts the positioning pin in the horizontal slide groove, and the long side of the specimen contacts the positioning pin in the vertical slide groove.
3. A universal fixture for low-speed impact testing of foam cushioning composite laminates according to claim 2, characterized in that: Scales are set on one side of the horizontal slide groove and one side of the vertical slide groove. The starting value of the scale on the horizontal slide groove side is the shortest distance between the horizontal slide groove and the central section of the wide side of the rectangular positioning hole, and the starting value of the scale on the vertical slide groove side is the shortest distance between the vertical slide groove and the central section of the long side of the rectangular positioning hole.
4. A universal fixture for low-speed impact testing of foam cushioning composite laminates according to claim 3, characterized in that: There are at least two transverse chutes and at least two vertical chutes.
5. A universal fixture for low-speed impact testing of foam cushioning composite laminates according to claim 4, characterized in that: There are two transverse slide grooves and two vertical slide grooves, the two transverse slide grooves are placed outside the two ends of the long side of the rectangular positioning hole, and the two vertical slide grooves are placed outside the two ends of the wide side of the rectangular positioning hole.
6. The universal fixture for low-speed impact testing of foam cushioning composite laminates according to claim 1, characterized in that: The support column comprises a rod part and a flange part, the first end of the rod part is connected to the center of the flange part, the second end of the rod part is connected to the testing machine, and the flange part is connected to the lower surface of the test bench through bolts.