Universal drop hammer for low-speed impact test of composite laminate

Abstract

The utility model discloses a general drop hammer for a low-speed impact test of a composite laminate. The general drop hammer comprises an external frame, a weight column, at least one weight, a hammer head, a positioning nut and four limiting blocks, the weight column is vertically mounted in the center of the bottom in the outer frame; threads are arranged on the side wall of the weight column. A screw hole is formed in the center of the weight which is in threaded fit with the weight column; the hammer head is vertically installed in the center of the bottom of the outer frame. The positioning nut is in threaded fit with the weight column, the positioning nut is arranged above the weight, and the lower surface of the positioning nut is in extrusion contact with the upper surface of the weight; according to the universal drop hammer, the total mass of the universal drop hammer is changed by increasing the number of the weights mounted on the weight column, so that the universal drop hammer can adapt to wide-range impact energy; the external frame, the weight column, the weight and the hammerhead are coaxially arranged, and the limiting block matched with the guide rail of the testing machine is arranged, so that the force loaded by the general drop hammer and the hammerhead are always positioned on the same axis, and the accuracy of the test is finally ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of experimental testing equipment, in particular to a universal drop hammer used for low-speed impact testing of composite material laminates. Background Art

[0002] Composite laminates are susceptible to varying degrees of low-speed impact damage during service, which can significantly reduce their strength and fatigue life. Accurate simulation of low-speed impact conditions of composite laminates is crucial to the structural design of composite materials. In order to adapt to the wide range of impact energy suffered during service, the impact energy of low-speed impact test equipment is required to be adjustable and cover the potential impact energy range. Under the constraint of a certain drop height of the drop hammer, the drop hammer mass is required to be adjustable. At present, the drop hammer mass block setting of drop hammer low-speed impact test equipment at home and abroad is difficult to adapt to the requirements of a wide range of impact energy, and the center of mass of the drop hammer mass assembly block is easy to deviate from the drop hammer axis, which makes it difficult for low-speed impact tests to accurately simulate the impact damage of composite laminates under a wide range of impact energy.

[0003] Therefore, it is necessary to develop a universal drop hammer for low-speed impact testing of composite laminates to solve the above problems. Utility Model Content

[0004] The utility model aims to solve the above problems and designs a universal drop hammer for low-speed impact test of composite material laminates.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0006] A general purpose drop weight for low velocity impact testing of composite laminates comprising:

[0007] External frame;

[0008] The weight column is vertically installed at the bottom center of the external frame; the side wall of the weight column is provided with a thread;

[0009] At least one weight; a screw hole is provided at the center of the weight, and the weight is threadedly matched with the weight column;

[0010] Hammer head; the hammer head is vertically installed at the bottom center of the external frame; the external frame, weight column, weight, and hammer head are arranged coaxially.

[0011] Specifically, the universal drop weight also includes a positioning nut; the positioning nut is threadedly matched with the weight column, the positioning nut is placed above the weight, and the lower surface of the positioning nut is in extrusion contact with the upper surface of the weight.

[0012] Preferably, the weight column is a cylindrical structure.

[0013] Preferably, the weight is a circular columnar structure.

[0014] Preferably, the outer frame is a rectangular frame structure.

[0015] Preferably, the bottom of the hammer head is formed into a spherical surface.

[0016] Furthermore, the universal drop hammer also includes four limit blocks, the first end of the limit block is provided with an arc groove, the second end of the limit block is fixedly connected to the side wall of the external frame, the four limit blocks are respectively installed on two opposite sides of the external frame, and the first end of the limit block is in contact with the guide rail of the testing machine.

[0017] Furthermore, two limit blocks installed on one side of the external frame are respectively placed at the upper and lower ends of one side of the external frame.

[0018] The beneficial effects of the utility model are:

[0019] 1. By increasing the number of weights installed on the weight column, the overall mass of the universal drop weight is changed, so that the universal drop weight can adapt to a wide range of impact energy;

[0020] 2. By arranging the external frame, weight column, weight, and hammer head on the same axis, and setting a limit block that cooperates with the guide rail of the testing machine, the force of the universal drop hammer loading is always on the same axis as the hammer head, ultimately ensuring the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the external framework in this application;

[0022] Figure 2 It is a schematic diagram of the structure of the hammer head in this application;

[0023] Figure 3 It is a schematic diagram of the structure of the weight column in this application;

[0024] Figure 4 It is a schematic diagram of the structure of the weight in this application;

[0025] Figure 5 It is a schematic diagram of the structure of the limit block in this application;

[0026] Figure 6 It is a schematic diagram of the overall structure of this application.

[0027] In the figure: 1-external frame; 2-hammer head; 3-weight column; 4-weight; 5-limiting block; 6-bolt; 7-positioning nut. DETAILED DESCRIPTION

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0033] 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.

[0034] The specific implementation of the utility model is described in detail below in conjunction with the accompanying drawings.

[0035] like Figure 1-6 A general drop weight for low-velocity impact testing of composite laminates is shown, comprising:

[0036] External frame 1; the external frame 1 is a rectangular frame structure;

[0037] The weight column 3 is a cylindrical structure; the weight column 3 is installed vertically, and the lower end of the weight column 3 is threadedly connected to the center of the bottom of the outer frame 1; the side wall of the weight column 3 is provided with a thread; a certain gap is left between the upper end of the weight column 3 and the top of the outer frame 1 to ensure that the weight 4 can be loaded and unloaded through the gap;

[0038] At least one weight 4 (may also include weights 4 of different masses); the weight 4 is a circular columnar structure; a screw hole is provided at the center of the weight 4, and the weight 4 is threadedly matched with the weight column 3;

[0039] Hammer 2; hammer 2 is installed vertically, and hammer 2 is connected to the bottom center of the external frame 1 by thread; the external frame 1, weight column 3, weight 4, and hammer 2 are arranged coaxially; the upper part of hammer 2 is cylindrical, the middle part is a frustum, the bottom of hammer 2 is formed into a spherical surface, and the upper part of hammer 2 has the largest diameter;

[0040] Positioning nut 7; the positioning nut 7 is threadedly matched with the weight column 3, the positioning nut 7 is placed above the weight 4, and the lower surface of the positioning nut 7 is in extrusion contact with the upper surface of the weight 4.

[0041] Four limit blocks 5; the limit blocks 5 are formed into a plate-like structure, the first end of the limit block 5 is provided with an arc groove, the limit block 5 is installed horizontally, four steps are provided at the four corners of the external frame 1 (on the two opposite sides of the external frame 1), the second end of the limit block 5 is vertically provided with two through holes, and two screw holes are provided on the step surface. The bolts 6 pass through the through holes on the limit block 5 and are screwed into the screw holes on the step surface to fix the limit block 5 to the external frame 1. The first end of the limit block 5 protrudes outward from the side wall of the external frame 1, the first ends of the two limit blocks 5 on the same side are flush, and the first end of the limit block 5 fits with the guide rail of the testing machine.

[0042] In the present application, the limit block 5 can ensure that the movement axis of the entire drop weight is always perpendicular to the sample, thereby satisfying that the force exerted by the drop weight on the sample during low-speed impact is perpendicular to the sample.

[0043] The setting of the limit block 5 in the present application can ensure that the left and right sides of the entire drop weight device are always parallel during movement, and the impact force acting on the sample is perpendicular to the sample.

[0044] In the present application, the weight 4 can be used to control the mass and energy changes of the entire drop weight device to meet diversified experimental requirements.

[0045] In the present application, the positioning nut 7 is mainly used to position the installed weight 4 to ensure that the weight 4 can be stably fixed on the weight column 3 during the low-speed impact process without any movement due to the vibration caused by the low-speed impact.

[0046] In the present application, the internal thread of the weight 4 enables the weight 4 to be fixedly connected to the weight column 3, and the number and mass of the weight 4 can be flexibly adjusted according to the experimental requirements, ensuring that all loaded forces are always on the same axis as the hammer head 2, thereby ensuring that the final impact force acting on the sample is perpendicular to the sample.

[0047] In the present application, the lower end of the hammer head 2 is set to a spherical structure, which ensures that the loaded force and energy are evenly distributed on the spherical part at the end of the hammer head 2.

[0048] In some embodiments, the screw hole provided at the center of the weight 4 can be replaced by a through hole. With the cooperation of the positioning nut 7, the positioning of the weight 4 can also be ensured to a certain extent.

[0049] The universal drop hammer with adjustable mass for low-speed impact testing of composite material laminates of the present invention realizes adjustable energy and mass of low-speed impact through reasonable and sophisticated coordination and connection among various subsystems. It can be simply and practically used for low-speed impact tests of composite material laminates under a wide range of impact energies, providing technical support and means for low-speed impact testing.

[0050] When the present application is working, the arc groove of the limit block 5 is closely connected with the guide rail of the testing machine. Then, according to the specific test requirements, a certain number of weights 4 are loaded into the weight column 3, and then the positioning nut 7 is installed on the weight column 3 to lock it, and then the low-speed impact test can be carried out.

[0051] 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 drop weight for low-speed impact testing of composite laminates, characterized in that: include: External frame; The weight column is vertically installed at the bottom center of the external frame; the side wall of the weight column is provided with a thread; At least one weight; a screw hole is provided at the center of the weight, and the weight is threadedly matched with the weight column; Hammer head; the hammer head is vertically installed at the bottom center of the external frame; the external frame, weight column, weight, and hammer head are arranged coaxially.

2. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The universal drop weight also includes a positioning nut; the positioning nut is matched with the thread of the weight column, the positioning nut is placed above the weight, and the lower surface of the positioning nut is in extrusion contact with the upper surface of the weight.

3. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The weight column is a cylindrical structure.

4. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The weight is a circular columnar structure.

5. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The outer frame is a rectangular frame structure.

6. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The bottom of the hammer head is formed into a spherical surface.

7. A universal drop weight for low-speed impact testing of composite laminates according to claim 1, characterized in that: The universal drop hammer also includes four limit blocks, the first end of the limit block is provided with an arc groove, the second end of the limit block is fixedly connected to the side wall of the external frame, the four limit blocks are respectively installed on two opposite sides of the external frame, and the first end of the limit block is in contact with the guide rail of the testing machine.

8. A universal drop weight for low-speed impact testing of composite laminates according to claim 7, characterized in that: Two limit blocks installed on one side of the external frame are respectively placed at the upper and lower ends of one side of the external frame.

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