Glass fiber reinforced plastic bonding component vibration fatigue evaluation method and equipment

Abstract

The invention relates to the technical field of glass fiber reinforced plastic bonding fatigue detection, and particularly discloses a glass fiber reinforced plastic bonding component vibration fatigue evaluation method. The method comprises the following steps: applying preset temperature, pressure, amplitude and frequency treatment to a glass fiber reinforced plastic bonding component according to the actual working condition of the glass fiber reinforced plastic pressure container; collecting data values of three-point bending strength, tensile strength and defect degree of the processed glass fiber reinforced plastic bonding component; and evaluating the data, and when any one of the three-point bending strength, the tensile strength and the defect degree is smaller than a specified value, evaluating that the vibration fatigue performance of the glass fiber reinforced plastic bonding component does not meet the requirement. Aiming at the lack of an effective service safety guarantee and evaluation method for an existing glass fiber reinforced plastic bonding component, a vibration fatigue evaluation mechanism and device are established, and long-term safe application of the glass fiber reinforced plastic bonding component is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of glass fiber reinforced plastic bonding fatigue detection, in particular to a method for evaluating vibration fatigue of a glass fiber reinforced plastic bonding component. Background Art

[0002] At present, the types of domestic oilfield pressure vessels are mainly carbon steel, and their internal structures are basically made of metal. During the annual maintenance process, it is found that the internal components, including internal pipelines, partitions, corrugated plates, flange blind plates, etc., are rusted or even corroded and perforated. The use of FRP components will completely solve the corrosion problem, and has obvious advantages in improving its service safety and reducing operation and maintenance costs. FRP components are made of glass fiber impregnated with resin. Its reinforcing materials include alkali-free glass fiber, glass fiber chopped mat, glass fiber stitched mat, glass fiber cloth, etc. Resins include epoxy resin (EP), unsaturated polyester resin (UP), vinyl ester resin (VE), phenolic resin (PF), furan resin (FU), etc. Among them, the most widely used are unsaturated polyester resin (UP) and vinyl ester resin (VE). For internal components, compression molding or hand lay-up molding is generally used, and components and components or components and substrates are generally connected by bonding. The internal components of FRP pressure vessels are made of non-metallic materials, which are much weaker than metal materials. Especially during operation, the medium inside the FRP pressure vessel will experience pressure fluctuations, which will cause vibrations in the bonded components, which will lead to fatigue failure in the long run. However, there is currently no corresponding evaluation method for the vibration fatigue problem of bonded components of FRP pressure vessels. Summary of the invention

[0003] On the one hand, the purpose of the present invention is to provide a vibration fatigue evaluation method for FRP bonded components. In view of the lack of effective service safety protection and evaluation methods for existing FRP bonded components, a vibration fatigue evaluation mechanism and device are established to ensure the long-term safe application of FRP bonded components.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for evaluating vibration fatigue of glass fiber reinforced plastic bonded components, the method comprising:

[0006] Referring to the actual working conditions of FRP pressure vessels, preset temperature, pressure, amplitude and frequency treatments are applied to FRP bonding components;

[0007] Collecting the three-point bending strength, tensile strength and defect degree data values ​​of the fiberglass reinforced plastic bonding component after processing;

[0008] The data are evaluated. When any one of the data values ​​of the three-point bending strength, the tensile strength and the degree of defects is less than the specified value, it is evaluated that the vibration fatigue performance of the FRP bonded component does not meet the requirements.

[0009] In a further embodiment, the method further comprises evaluating the three-point bending strength and tensile strength reduction rate of the FRP bonding component.

[0010] In a further embodiment, the processing method includes placing the FRP bonding component into a container containing a medium, clamping one end of the FRP bonding component by a component clamping device in the container, and clamping the other end of the FRP bonding component by an electromagnetic vibrator;

[0011] The temperature of the medium and the pressure applied to the FRP bonding component are adjusted to preset values ​​by the temperature control device and the pressure control device respectively, and the vibration amplitude and frequency of the FRP bonding component are adjusted to preset values ​​by the electromagnetic vibration control device.

[0012] In a further solution, the preset temperature value is 60° C., the preset medium pressure value is 1.2 MPa, the preset medium vibration amplitude value is 1 mm, and the preset frequency value is 50 Hz.

[0013] In a further embodiment, the medium includes diesel, hydraulic oil or water.

[0014] In a further embodiment, the specified value is determined based on the thickness and bonding range of the FRP bonding component.

[0015] In a further embodiment, the FRP bonding component is prepared by impregnating alkali-free glass fiber with vinyl ester resin.

[0016] Another aspect of the present invention provides a FRP bonding component vibration fatigue evaluation device configured in accordance with the above method, the device comprising a pre-processing module, the pre-processing module being used to apply a preset temperature, pressure, amplitude and frequency treatment to the FRP bonding component;

[0017] A collection module, used to collect the three-point bending strength, tensile strength and defect degree of the fiberglass bonded components within the evaluation period;

[0018] The evaluation module is used to evaluate whether the data values ​​taken by the acquisition module meet the fatigue performance requirements of the FRP bonded components.

[0019] In a further scheme, the pretreatment module includes a container, a component clamping device, an electromagnetic vibrator, an electromagnetic vibration control device, a pressure control device and a temperature control device. The container is a closable shell. The component clamping device is arranged in the container for clamping one end of the fiberglass reinforced plastic bonding component. The electromagnetic vibrator is arranged in the container for clamping the other end of the fiberglass reinforced plastic bonding component. The electromagnetic vibration control device is connected to the electromagnetic vibrator for controlling the vibration frequency and vibration amplitude of the vibration end of the electromagnetic vibrator. The pressure control device is connected to the container for controlling the medium pressure in the container. The temperature control device is connected to the container for controlling the medium temperature in the equipment container.

[0020] In a further embodiment, the acquisition module includes a testing device, which is used for testing three-point bending strength and tensile strength and collecting, storing and transmitting data.

[0021] Beneficial effects of the present invention:

[0022] The present invention simulates the vibration behavior of FRP bonded components under actual service conditions and analyzes the vibration fatigue resistance of FRP components under medium, temperature and pressure conditions, thereby providing an effective way to prevent vibration fatigue failure of FRP components and evaluate the vibration fatigue resistance of in-service components.

[0023] The vibration fatigue test equipment is used, and the vibration frequency is adjustable. Vibration simulation under different frequency conditions can be achieved through the control of the electromagnetic vibrator (6). The mechanical properties of the samples before and after the vibration fatigue test are estimated, and the performance degradation ratio is compared, so as to determine the vibration fatigue resistance of the glass fiber reinforced plastic bonded component and establish a scientific material selection evaluation method for the application of the component. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of a flow chart of a method for evaluating vibration fatigue of a glass fiber reinforced plastic bonding component in an embodiment of the present invention;

[0026] Figure 2 This is a structural block diagram of a preprocessing module of a FRP bonding component vibration fatigue evaluation device according to an embodiment of the present invention;

[0027] In the figure: 1 is a container; 2 is a component clamping device; 3 is one end of the FRP bonding component; 4 is the FRP component bonding part; 5 is the other end of the FRP bonding component; 6 is an electromagnetic vibrator; 7 is a medium; 8 is a test device cover; 9 is a medium filling unit; 10 is an electromagnetic vibration control device; 11 is a pressure control device; 12 is a temperature control device. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0029] Vibration fatigue evaluation method for glass fiber reinforced plastic bonded components, the method includes:

[0030] Referring to the actual working conditions of FRP pressure vessels, preset temperature, pressure, amplitude and frequency treatments are applied to FRP bonding components;

[0031] Collect the three-point bending strength, tensile strength and defect degree data of the FRP bonded components after treatment;

[0032] Evaluation data: when any one of the three-point bending strength, tensile strength and defect degree is less than the specified value, the vibration fatigue performance of the FRP bonded components does not meet the requirements.

[0033] The specific implementation method may be, see Figure 1 As shown, step one: prepare the above-mentioned FRP bonding component as an experimental piece by impregnating vinyl ester resin with alkali-free glass fiber, such as cutting standardized specimens of the components prepared by impregnating vinyl ester resin with ready-made alkali-free glass fiber, and the specimen size is a long strip, length × width × thickness is 100mm × 25mm × 3mm. And two specimens of the same size are bonded, the overlap length is 12.5mm, and the adhesive used is vinyl ester resin. A total of 10 pairs of specimens are prepared according to the same process. Among them, 5 pairs are used for various performance tests of the initial specimens, and 5 pairs are used for performance tests after vibration fatigue tests. The test items are defect degree observation such as morphological defect observation, 3-point bending performance test, and tensile strength test. The average maximum three-point bending failure load is 585N, the average tensile strength is 11.68MPa, and there are no initial defects.

[0034] See also Figure 2As shown, step 2: install a pair of prepared FRP bonding component samples into the container 1, wherein one end 3 of the FRP bonding component sample is fixed on the sample component clamping device 2, and the other end 5 of the FRP bonding component sample is installed with an electromagnetic vibrator 6. After the sample is installed, cover the test device cover 8 and ensure the sealing performance. Then fill the medium 7 through the medium filling unit 9. The medium 7 used this time is 0# diesel. After the filling is completed, the filling unit is sealed to ensure that the medium 7 does not overflow during the test. Debug the pressure control device 11 and the temperature control device 12 to meet the test conditions.

[0035] Step 3: Start the test, set the pressure control device 11 to 1.2 MPa, set the temperature control device 12 to 60°C. Adjust the electromagnetic vibration control device 10 outside the electromagnetic vibrator 6, set the vibration frequency to 50 Hz, the amplitude value to 1 mm, and the entire test cycle duration to 24 hours; the above preset values ​​are consistent with the commonly used values ​​of the components in the glass container 1 in the oil pipe.

[0036] Step 4: After completing the vibration fatigue test of 5 parallel samples in sequence, the tensile properties of the sample are tested. The test items are the same as the initial sample. The test results are as follows: no defects are observed in the morphology; the average maximum three-point bending failure load is 543N, and the average tensile strength is 11.23MPa;

[0037] Step 5: Compare and analyze the changes in the mechanical properties of the samples after the initial test and the vibration fatigue test, characterize the vibration fatigue attenuation of the FRP bonded components, and the overall morphology does not change, indicating that the bonding part of the FRP component has no cracking after experiencing vibration fatigue, the bending load decrease rate is 7.18%, and the tensile strength decrease rate is 3.85%. The overall evaluation results show that the FRP bonded component has good vibration fatigue resistance and can meet the application under this working condition.

[0038] Those skilled in the art should be able to imagine that, step 1: the preparation batches of the fiberglass bonded component samples can be multiple batches, and some batches of samples are subjected to initial mechanical property tests, and other batches are used for vibration fatigue tests;

[0039] In step 2, the pressure control device 1111 may use a pressure control solenoid valve, and the medium filling unit 9 may use a pressure pump to fill the medium, and the pressure control solenoid valve may be used to control the pressure of the medium 7 filled by the pressure pump.

[0040] Step 3: Start the vibration fatigue test and set various test parameters according to the test conditions; the temperature control device 12 can use an existing temperature controller.

[0041] In step 4, after completing a certain cycle of vibration fatigue test, the tensile properties of the sample are tested; the cycle time can be selected according to actual conditions or can be an intermittent time.

[0042] In step 5, the changes in the mechanical properties of the samples after the initial test and the vibration fatigue test are compared and analyzed to characterize the vibration fatigue attenuation of the FRP bonded components. The degree of defects can be observed by a defect magnification instrument.

[0043] Those skilled in the art should be able to conceive that by evaluating the three-point bending strength and tensile strength reduction rate of the FRP bonded components, a relationship between the expected life span of the FRP bonded components can be established, and a replacement schedule for related components can be reasonably arranged to ensure safe use.

[0044] In actual working conditions, the temperature of the FRP pressure vessel ranges from -30°C to 100°C, the pressure of the medium 7 ranges from 0.1MPa to 2MPa, the vibration amplitude of the medium 7 ranges from 0.1 to 2mm, and the frequency ranges from 1 to 10000Hz. Theoretically, the above actual values ​​can be enlarged or further reduced, and the experimental conditions can be set according to actual sudden needs, which will not be described here one by one.

[0045] The medium 7 includes diesel, hydraulic oil or water.

[0046] The specified value is determined based on the thickness of the FRP bonded components and the bonding range, and can also refer to the existing national standards for the pressure resistance, tensile resistance, and fatigue resistance of the relevant components of the FRP container 1.

[0047] FRP bonded components can also be prepared by impregnating other glass fibers with resin.

[0048] Obviously, we can obtain an evaluation device for vibration fatigue of glass fiber reinforced plastic bonding components, the device includes a pretreatment module, the pretreatment module is used to apply preset temperature, pressure, amplitude and frequency treatment to the glass fiber reinforced plastic bonding components;

[0049] The collection module is used to collect the three-point bending strength, tensile strength and defect degree of the FRP bonding components during the evaluation period;

[0050] The evaluation module is used to evaluate whether the data values ​​taken by the acquisition module meet the fatigue performance requirements of the FRP bonded components.

[0051] Specifically, the pretreatment module may include a container 1, a component clamping device 2, an electromagnetic vibrator 6, an electromagnetic vibration control device 10, a pressure control device 11 and a temperature control device 12. The container 1 is a closable shell. The component clamping device 2 is arranged in the container 1 for clamping one end 3 of the fiberglass reinforced plastic bonding component. The electromagnetic vibrator 6 is arranged in the container 1 for clamping the other end 5 of the fiberglass reinforced plastic bonding component. The electromagnetic vibration control device 10 is connected to the electromagnetic vibrator 6 for controlling the vibration frequency and vibration amplitude of the vibration end of the electromagnetic vibrator 6. The pressure control device 11 is connected to the container 1 for controlling the pressure of the medium 7 in the container 1. The temperature control device 12 is connected to the container 1 for controlling the temperature of the medium 7 in the equipment container 1.

[0052] The acquisition module comprises a testing device, which is used for testing three-point bending strength and tensile strength and for collecting, storing and transmitting data.

[0053] The evaluation module can be some existing data processors.

[0054] It should be noted that the terms "first", "second" etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged in appropriate circumstances, so that the embodiments of the present application described here. In the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" etc. are based on the orientation or positional relationship shown in the accompanying drawings.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. 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 can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for evaluating vibration fatigue of glass fiber reinforced plastic bonded components, characterized in that: The method comprises: Referring to the actual working conditions of FRP pressure vessels, preset temperature, pressure, amplitude and frequency treatments are applied to FRP bonding components; Collecting the three-point bending strength, tensile strength and defect degree data values ​​of the fiberglass reinforced plastic bonding component after processing; The data are evaluated. When any one of the data values ​​of the three-point bending strength, the tensile strength and the degree of defects is less than the specified value, it is evaluated that the vibration fatigue performance of the FRP bonded component does not meet the requirements.

2. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 1, characterized in that: The method further comprises evaluating the three-point bending strength and tensile strength reduction rate of the FRP bonding component.

3. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 1, characterized in that: The processing method comprises placing a glass fiber reinforced plastic bonding component into a container (1) containing a medium (7), clamping one end (3) of the glass fiber reinforced plastic bonding component by a component clamping device (2) in the container (1), and clamping the other end (5) of the glass fiber reinforced plastic bonding component by an electromagnetic vibrator (6); The temperature of the medium (7) and the pressure applied to the FRP bonding component are respectively adjusted to preset values ​​by the temperature control device (12) and the pressure control device (11), and the vibration amplitude and frequency of the FRP bonding component are adjusted to preset values ​​by the electromagnetic vibration control device (10).

4. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 3, characterized in that: The preset value of the medium (7) temperature is 60° C., the preset value of the medium (7) pressure is 1.2 MPa, and the preset value of the medium (7) vibration amplitude is 1 mm. The preset value of the frequency is 50 Hz.

5. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 3, characterized in that: The medium (7) includes diesel, hydraulic oil or water.

6. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 1, characterized in that: The specified value is determined based on the thickness and bonding range of the FRP bonding component.

7. The method for evaluating vibration fatigue of glass fiber reinforced plastic bonding components according to claim 1, characterized in that: The glass fiber reinforced plastic bonding component is prepared by impregnating alkali-free glass fiber with vinyl ester resin.

8. Vibration fatigue evaluation equipment for glass fiber reinforced plastic bonding components, characterized in that: The device includes a pre-processing module, which is used to apply preset temperature, pressure, amplitude and frequency treatment to the FRP bonding component; A collection module, used to collect the three-point bending strength, tensile strength and defect degree of the fiberglass bonded components within the evaluation period; The evaluation module is used to evaluate whether the data values ​​taken by the acquisition module meet the fatigue performance requirements of the FRP bonded components.

9. The FRP bonding component vibration fatigue evaluation equipment according to claim 8, characterized in that: The pretreatment module comprises a container (1), a component clamping device (2), an electromagnetic vibrator (6), an electromagnetic vibration control device (10), a pressure control device (11) and a temperature control device (12); the container (1) is a closable shell; the component clamping device (2) is arranged in the container (1) and is used to clamp one end (3) of the glass fiber reinforced plastic bonding component; the electromagnetic vibrator (6) is arranged in the container (1) and is used to clamp the other end (5) of the glass fiber reinforced plastic bonding component; the electromagnetic vibration control device (10) is connected to the electromagnetic vibrator (6) and is used to control the vibration frequency and vibration amplitude of the vibration end of the electromagnetic vibrator (6); the pressure control device (11) is connected to the container (1) and is used to control the pressure of a medium (7) in the container (1); and the temperature control device (12) is connected to the container (1) and is used to control the temperature of the medium (7) in the equipment container (1).

10. The FRP bonding component vibration fatigue evaluation equipment according to claim 9, characterized in that: The acquisition module includes a testing device, which is used for testing three-point bending strength and tensile strength and collecting, storing and transmitting data.

Images