Mechanical bearing measurement system and method of composite bulwark structure

Abstract

The invention provides a mechanical bearing measurement system and method for a composite bulwark structure, and the system comprises a test tool, a bulwark to be measured and a mechanical property measurement mechanism, the test tool comprises a bulwark fixing support, one side of the bulwark to be measured is fixed to the upper part of the side surface of the bulwark fixing support, and the bulwark to be measured is provided with a loading object; the mechanical property measuring mechanism comprises a stress monitoring system and a displacement measuring system which are used for measuring the stress value and the displacement amount of the bulwark to be measured respectively, and by measuring the point displacement, the strain value and the deformation condition of the bulwark after loading, the problem of evaluating the mechanical bearing capacity of the bulwark structure under the action of uniformly distributed loads is effectively solved; the method can be used as a reliable means for checking and verifying the strength and rigidity.

Description

Technical Field

[0001] The invention belongs to the technical field of ship engineering hull structure design, and in particular relates to a mechanical bearing measurement system and method for a composite material bulwark structure. Background Art

[0002] Composite materials structures are widely used in aerospace, automotive, shipbuilding, chemical and other fields due to their excellent specific stiffness, specific strength and designability.

[0003] Composite bulwarks are generally arranged in the open air of the ship's deck. In addition to being affected by environmental factors such as solar radiation, salt spray, humidity, heat, high and low temperatures, they are also subject to wind loads, waves on the deck, and loads such as personnel leaning on them, which require certain mechanical bearing capacity. At present, there are relevant standards and specifications for reference in the measurement methods of material-level properties such as mechanical properties and environmental adaptability of composite structures. However, due to the strong designability of composite structures, various structural types of composite structures, such as spherical, hemispherical, special-shaped, cubic, etc., can be formed by mold pressing. It is impossible to establish a unified standard for the measurement of structural-level properties such as mechanical bearing capacity. How to convert the mechanical bearing capacity of the bulwark into an indicator that can be quantified for evaluation needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mechanical bearing capacity measurement system and method for a composite bulwark structure in view of the above-mentioned problems, which fully considers the structural type and load characteristics of the measurement object, and proves through engineering practice that the mechanical bearing capacity measurement results are authentic and reliable.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a mechanical bearing measurement system of a composite material bulwark structure, characterized in that it comprises a test fixture, a bulwark to be tested and a mechanical property measurement mechanism, the test fixture comprises a bulwark fixing bracket, one side of the bulwark to be tested is fixed to the upper side of the bulwark fixing bracket, a load is arranged on the bulwark to be tested, and the mechanical property measurement mechanism comprises a stress monitoring system and a displacement measurement system, which respectively measure the stress value and displacement of the bulwark to be tested.

[0006] According to the above solution, the test fixture also includes an auxiliary bracket, and the bottom of the auxiliary bracket is connected to a bottom extension section of one side of the bulwark fixing bracket.

[0007] According to the above solution, the bulwark fixing bracket is a triangular frame structure, and a connecting base is provided on the contact surface connected with the bulwark to be tested.

[0008] According to the above scheme, the stress monitoring system includes a strain gauge and a strain gauge. The strain gauge is attached to the surface of the bulwark to be measured, and the strain gauge is electrically connected to the strain gauge through a data transmission line.

[0009] According to the above scheme, the displacement measurement system is a scale or a displacement meter, which measures the height value of the same measurement point relative to the ground before and after loading on the bulwark to be measured.

[0010] According to the above solution, the auxiliary bracket is a rectangular frame structure with openings on the top and inside, and the inside openings are oriented toward the bulwark to be measured to form an enclosing structure.

[0011] According to the above solution, a layer of hard rubber sheet is laid between the top surface of the bulwark to be tested and the load.

[0012] According to the above solution, the loading object is a sandbag.

[0013] A method for measuring a mechanical bearing measurement system of a composite bulwark structure, characterized in that it comprises the following steps:

[0014] Step a, use bolts to fix the bulwark to be tested on the test fixture so that the panel of the bulwark to be tested remains horizontal; connect the stress monitoring system to the bulwark to be tested, distribute the stress measurement points in the areas with large stress levels or areas of key concern, and then select the displacement measurement system according to the accuracy requirements and measurement conditions;

[0015] Step b: select a displacement measurement reference point on the bulwark to be measured, and measure the vertical height value h of the displacement measurement reference point before loading by using the displacement measurement system. 0 , pile the load on the bulwark to be measured, and then measure the vertical height value h of the displacement measurement reference point at this time 1 , the stress monitoring system collects the strain value of the stress measuring point during the loading process and analyzes the stress condition of the bulwark to be tested;

[0016] Step c, remove the sandbags, unload the bulwark to be tested, and measure the vertical height h of the displacement measurement reference point at this time 2 , determine the evaluation criteria for the mechanical properties of the bulwark to be tested, obtain the maximum deformation value of the bulwark after loading and the deformation recovery after unloading through the displacement change value, and evaluate whether the mechanical bearing capacity of the bulwark to be tested meets the technical requirements.

[0017] According to the above scheme, the evaluation standard is that the deformation Δh of the bulwark to be tested does not exceed 1 / 70 of the span length of the bulwark, and the plastic deformation value Δh′ after unloading does not exceed 1 mm; the calculation formulas of the deformation Δh and the plastic deformation value Δh′ are as follows:

[0018] Δh=|h 1 -h 0 |

[0019] Δh′=|h 2 -h 0 |.

[0020] The beneficial effects of the present invention are as follows: 1. A mechanical bearing measurement system and method for a composite bulwark structure are provided, and a test fixture is manufactured to simulate actual constraint conditions and load requirements. By measuring the point displacement, strain value and deformation of the bulwark after loading, the problem of evaluating the mechanical bearing capacity of the bulwark structure under uniformly distributed load is effectively solved, and it can be used as a reliable means to assess and verify its strength and stiffness;

[0021] 2. The measurement system and method can be used to simulate the actual loading environment, convert the mechanical bearing capacity of the composite bulwark structure into easily measurable point displacements, strain values, etc., and evaluate its mechanical properties simply and intuitively. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 Schematic diagram of the structure of the measurement system according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] 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.

[0027] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0032] The mechanical bearing capacity measurement system of composite bulwark structure consists of test fixtures, measuring instruments and loads applied to the structure. According to the specific structural type of the bulwark, special bulwark fixtures are designed or modified; according to the physical quantity to be measured, appropriate measuring equipment is selected; according to the load type, the corresponding load and load application method are selected, and finally the mechanical bearing capacity of the structure is obtained by implementing the test.

[0033] like Figure 1 As shown, the mechanical bearing measurement system of the composite bulwark structure in the embodiment of the present invention comprises a test fixture 1, a bulwark to be tested 2 and a mechanical property measuring mechanism, wherein the test fixture comprises a bulwark fixing bracket, one side of the bulwark to be tested is fixed to the upper part of the side of the bulwark fixing bracket, a load is arranged on the bulwark to be tested, and the mechanical property measuring mechanism comprises a stress monitoring system and a displacement measuring system, which respectively measure the stress value and the displacement of the bulwark to be tested.

[0034] Furthermore, the test fixture also includes an auxiliary bracket 3, the bottom of which is connected to a bottom extension section of one side of the bulwark fixing bracket.

[0035] Example 1

[0036] The auxiliary bracket is a rectangular frame structure with openings on the top and inside, and the inside openings are facing the bulwark to be tested to form an enclosure structure. The length, width and height dimensions of the auxiliary bracket are slightly larger than those of the test fixture, so as to prevent the load from falling and causing safety accidents when the load is stacked on the bulwark to be tested.

[0037] In this embodiment 1, the bulwark fixing bracket is a triangular frame structure, and the triangular structure ensures that no deformation occurs under the test state. A connecting base is provided on the contact surface where the bulwark fixing bracket is connected to the bulwark to be tested. The connecting base is provided with evenly distributed bolt holes and bolts for connecting and fixing the composite material bulwark to simulate actual installation conditions; according to the different bulwark structure types or force directions, different types of connecting bases can be designed and selected to match the object to be tested.

[0038] In this embodiment 1, a layer of hard rubber plate is laid between the top surface of the bulwark to be tested and the load to ensure uniform load distribution.

[0039] Example 2

[0040] In this embodiment, the stress monitoring system includes a strain gauge 4 and a strain gauge, the strain gauge is attached to the surface of the bulwark to be measured, and the strain gauge is electrically connected to the strain gauge through a data transmission line 5. The strain gauge collects the strain of a typical measuring point during the loading process to analyze the stress condition of the bulwark structure.

[0041] Furthermore, the displacement measurement system is a scale or displacement meter, which measures the height of the same measurement point relative to the ground before and after loading of the bulwark to be measured. The displacement measurement system can obtain the displacement change of the bulwark structure during loading, after loading and after unloading by reading the indications multiple times, and the maximum deformation value of the bulwark after loading and the deformation recovery after unloading can be obtained through the displacement change value.

[0042] The technical key points of the measurement system and measurement method for evaluating the mechanical bearing capacity of composite bulwark structures are as follows:

[0043] (1) Design test fixtures for composite bulwark structures, use bolts to fix the bulwark and fixtures to simulate actual installation conditions;

[0044] (2) fixed measuring instruments to measure the deformation of the bulwark under various working conditions;

[0045] (3) Apply load according to the test conditions and record the instrument readings;

[0046] (4) Unloading: Observe the surface quality and deformation of the bulwark after unloading.

[0047] Example 3

[0048] In this embodiment, the mechanical properties of the bulwark structure under uniform load are tested. Therefore, a sandbag with a weight of 20 kg is selected as the load. The load is measured by F = P*S, m = F / g (F-force, N; P-pressure, Pa; S-area, m 2 ; m-mass, kg; g=9.8N / kg) calculate the weight to be loaded.

[0049] 1. Use bolts to fix the bulwark to be tested on the test fixture to keep the panel of the bulwark horizontal; connect the stress monitoring system to the bulwark to be tested, distribute the stress measurement points in the areas with high stress levels or key areas of concern, and then select the displacement measurement system according to the accuracy requirements and measurement conditions.

[0050] 2. Select a displacement measurement reference point on the bulwark to be measured, measure the vertical height value h0 of the displacement measurement reference point before loading through the displacement measurement system, pile the load on the bulwark to be measured, and then measure the vertical height value h1 of the displacement measurement reference point at this time. The stress monitoring system collects the strain value of the stress measurement point during the loading process and analyzes the stress condition of the bulwark to be measured.

[0051] 3. Remove the sandbags, unload the bulwark to be tested, measure the vertical height value h2 of the displacement measurement reference point at this time, determine the evaluation standard of the mechanical properties of the bulwark to be tested, obtain the maximum deformation value of the bulwark after loading and the deformation recovery after unloading through the displacement change value, and evaluate whether the mechanical bearing capacity of the bulwark to be tested meets the technical requirements.

[0052] The standards for evaluating the mechanical properties of composite bulwark structures are that the deformation does not exceed 1 / 70 of the span of the bulwark, there is no obvious plastic deformation after unloading, and the plastic deformation value does not exceed 1mm.

[0053] The calculation formulas for deformation Δh and plastic deformation value Δh′ are as follows:

[0054] Δh=|h 1 -h 0 |

[0055] Δh′=|h 2 -h 0 |.

[0056] The specific evaluation results are shown in Table 1 below:

[0057] Table 1 Loading test results

[0058]

[0059]

[0060] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A mechanical load measurement system for composite bulwark structure, characterized in that: The invention comprises a test tool, a bulwark to be tested and a mechanical property measuring mechanism. The test tool comprises a bulwark fixing bracket. One side of the bulwark to be tested is fixed to the upper side of the bulwark fixing bracket. A load is arranged on the bulwark to be tested. The mechanical property measuring mechanism comprises a stress monitoring system and a displacement measuring system, which respectively measure the stress value and displacement of the bulwark to be tested.

2. A mechanical load measurement system for composite bulwark structure according to claim 1, characterized in that: The test fixture also includes an auxiliary bracket, the bottom of which is connected to a bottom extension section of one side of the bulwark fixing bracket.

3. The mechanical load measurement system of a composite material bulwark structure according to claim 2, characterized in that: The bulwark fixing bracket is a triangular frame structure, and a connecting base is provided on the contact surface connected with the bulwark to be tested.

4. A mechanical load measurement system for a composite bulwark structure according to claim 1 or 3, characterized in that: The stress monitoring system comprises a strain gauge and a strain gauge. The strain gauge is attached to the surface of the bulwark to be measured, and the strain gauge is electrically connected to the strain gauge via a data transmission line.

5. The mechanical load measurement system of a composite material bulwark structure according to claim 4, characterized in that: The displacement measuring system is a scale or a displacement meter, which measures the height of the same measuring point relative to the ground before and after loading on the bulwark to be measured.

6. A mechanical load measurement system for a composite bulwark structure according to claim 2 or 5, characterized in that: The auxiliary bracket is a rectangular frame structure with openings on the top and inside, and the inside openings are oriented toward the bulwark to be measured to form an enclosed structure.

7. A mechanical load measurement system for composite bulwark structure according to claim 6, characterized in that: A layer of hard rubber plate is laid between the top surface of the bulwark to be tested and the load.

8. A mechanical load measurement system for a composite bulwark structure according to claim 1 or 7, characterized in that: The loading object is a sandbag.

9. A measurement method using a mechanical bearing measurement system for a composite bulwark structure as claimed in claim 5, characterized in that: The steps include: Step a, use bolts to fix the bulwark to be tested on the test fixture so that the panel of the bulwark to be tested remains horizontal; connect the stress monitoring system to the bulwark to be tested, distribute the stress measurement points in the areas with large stress levels or areas of key concern, and then select the displacement measurement system according to the accuracy requirements and measurement conditions; Step b, selecting a displacement measurement reference point on the bulwark to be measured, measuring the vertical height value h0 of the displacement measurement reference point before loading by the displacement measurement system, stacking the load on the bulwark to be measured, and then measuring the vertical height value h1 of the displacement measurement reference point at this time, and the stress monitoring system collects the strain value of the stress measurement point during the loading process to analyze the stress condition of the bulwark to be measured; Step c, remove the sandbags, unload the bulwark to be tested, measure the vertical height value h2 of the displacement measurement reference point at this time, determine the evaluation standard of the mechanical performance of the bulwark to be tested, obtain the maximum deformation value of the bulwark after loading and the deformation recovery after unloading through the displacement change value, and evaluate whether the mechanical bearing capacity of the bulwark to be tested meets the technical requirements.

10. The mechanical bearing measurement method of a composite material bulwark structure according to claim 9, characterized in that: The evaluation standard is that the deformation Δh of the bulwark to be tested does not exceed 1 / 70 of the span length of the bulwark, and the plastic deformation value Δh′ after unloading does not exceed 1 mm; the calculation formulas for the deformation Δh and the plastic deformation value Δh′ are as follows: Δh=|h1-h0| Δh′=|h2-h0|.

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