CN109991092B - Natural exposure experimental device, system and method for component under variable amplitude load - Google Patents

Natural exposure experimental device, system and method for component under variable amplitude load Download PDF

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CN109991092B
CN109991092B CN201910202289.8A CN201910202289A CN109991092B CN 109991092 B CN109991092 B CN 109991092B CN 201910202289 A CN201910202289 A CN 201910202289A CN 109991092 B CN109991092 B CN 109991092B
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load
water
loading
water tank
test piece
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CN109991092A (en
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黄培彦
林嘉祥
陈展标
郭馨艳
李稳
郑小红
杨怡
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South China University of Technology SCUT
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/02—Details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
    • G01N3/12—Pressure testing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/0202—Control of the test
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

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Abstract

The invention relates to a natural exposure experimental device, a system and a method for a component under variable amplitude load, wherein the natural exposure experimental device for the component under variable amplitude load comprises a plurality of strip-shaped test pieces, two ground beams arranged in parallel, a loading water tank and a control device, the test pieces are placed on the two ground beams, the distance between the two ground beams is matched with the length of the test pieces, a digital display type strain gauge and a displacement meter are arranged at the middle position of the bottom of each test piece, the loading water tank is arranged above the test pieces, two loading heads arranged in parallel are arranged between the loading water tank and the test pieces, a liquid level sensor is arranged at the bottom of the inner side of the loading water tank, the water tank is provided with a water inlet pipe and a water outlet pipe, and the natural exposure experimental device further comprises a water storage device, a controller, a water supply pump, a water drainage pump, a main water inlet pipe and a main water outlet pipe. The natural exposure experimental device for the component under the variable amplitude load can realize the natural exposure experiment of the component under the coupling/combined action of various environments and the variable amplitude load, and has good universality and wide application range.

Description

Natural exposure experimental device, system and method for component under variable amplitude load
Technical Field
The invention relates to the field of material and structural mechanics experiments, in particular to a natural exposure experimental device, a natural exposure experimental system and a natural exposure experimental method for a component under variable amplitude load.
Background
The external load usually born by the major equipment or the major engineering structure in the fields of aerospace, land traffic, civil construction, ships, ocean engineering, water conservancy and hydropower, ports, wind power generation, engineering machinery and the like is variable-amplitude load or even random load which changes along with time and space. For the fatigue resistance/durability design and safety evaluation of the important equipment and the important engineering structure, the current experimental data are mainly constant amplitude fatigue acceleration experiments from indoor materials (small test pieces) and amplitude variation load acceleration experiments with extremely small quantity. Obviously, the experimental conditions (environment and load) are greatly different from the actual service conditions of the above-mentioned important equipment and important engineering structures, and the equipment and structure design and safety evaluation are performed based on the data obtained from the indoor accelerated experiment, so that potential safety hazards are left or extremely conservative design methods are adopted, thereby increasing the cost and wasting resources.
In order to economically and accurately obtain the anti-fatigue/durability performance of the heavy equipment and the heavy engineering structure under the actual service environment and load, the most ideal method is to develop a small amount of heavy equipment and heavy engineering structure models or important components under variable amplitude load, and combine the natural exposure experiment with a large amount of acceleration experiments simulating the service environment and load coupling/combined action of the heavy equipment and the heavy engineering structure models. However, the following major difficulties are encountered in conducting natural exposure experiments of structures or components under variable amplitude loading: 1) setting, applying and precisely controlling the variable load in long-term exposure experiments are difficult. For long-term, continuous and accurate application and control of variable amplitude load in a natural exposure experiment, no good method exists at present; 2) the natural exposure experimental device and method for the structure or the member under the variable amplitude load are not reported, and the natural exposure experimental device and method which can be applied to the structure or the member under the variable amplitude load in multiple environments and multiple test pieces are unheard of; 3) the long-term continuous accurate test and acquisition of experimental data under the coupling/combined action of the natural exposure environment and the variable amplitude load are difficult. The static deformation of materials or small test pieces in the natural exposure experiment reported at present is tested by a strain gauge and the like, but the test method adopting the strain gauge is difficult to realize long-term continuous test and acquisition due to the short service life, the environmental influence, the difficulty in power and other guarantee measures; 4) long-term operation of experimental sites, experimental conditions and devices, etc. is difficult. The period of the natural exposure experiment generally needs tens of years or even hundreds of years, and the set experiment conditions (environment, stress and the like) are maintained in the long period, the function and the stability of the experiment device are guaranteed, the experiment field is maintained and the like are all extremely difficult; 5) under natural exposure environment, a stress and deformation test method of a structure or a member (test piece) under variable amplitude load needs to be perfected. On one hand, the existing test method cannot adapt to the test of the deformation and stress change rule of the test piece caused by the change of the environment where the test piece is located, cannot completely, real-timely and accurately capture the data of the deformation and stress of the test piece changing along with the change of the environment, and is difficult to accurately measure the deformation of the test piece at the moment of sudden load change. On the other hand, the conventional natural exposure experimental device cannot simultaneously carry out natural exposure experiments under the combined action of the same environment and load on a plurality of or a batch of test pieces, and is not beneficial to carrying out statistical analysis on the long-term mechanical properties of the test pieces.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention aims to provide a natural exposure experimental device for a component under variable amplitude load, which can accurately control the load in a long-term experiment, is suitable for the experiment under multiple environments, is convenient for the long-term continuous test of experimental data, is convenient for data acquisition and is convenient for maintenance.
Aiming at the technical problems in the prior art, the invention also aims to provide a natural exposure experiment system of the component under the variable amplitude load, which can further accurately control the load, can simultaneously test a plurality of test pieces, is suitable for the experiment under multiple environments, is convenient for the long-term continuous test of experiment data, is convenient for data acquisition and is convenient for maintenance.
Aiming at the technical problems in the prior art, the invention also aims to provide a natural exposure experiment method of the component under the variable amplitude load, which can accurately simulate, apply and control the variable amplitude load in a long-term experiment, can completely, real-timely and accurately capture the data of the deformation and the stress of the test piece changing along with the change of the environment and the load, and can simultaneously carry out the natural exposure experiment under the coupling/combined action of the same environment and different environments and the variable amplitude load on a plurality of test pieces.
In order to achieve the purpose, the invention adopts the following technical scheme:
become the natural experimental apparatus that exposes of component under width of cloth load, test piece including a plurality of rectangular shapes, two grade beams of parallel arrangement, loading water tank and controlling means, a plurality of test pieces are placed on two grade beams, distance between two grade beams suits with the length of test piece, the bottom intermediate position of test piece is equipped with digital display strainometer and displacement meter, the top of test piece is equipped with loading water tank, be equipped with two parallel arrangement's loading head between loading water tank and the test piece, loading water tank inboard bottom is equipped with level sensor, loading water tank is equipped with inlet tube and outlet pipe, be equipped with the solenoid valve that intakes on the inlet tube, be equipped with the water solenoid valve on the outlet pipe.
Further, the loading head is a cylindrical loading head, and the loading head is in line contact with the test piece.
Further, one side of the ground beam facing the test piece is a cylindrical surface.
Further, the below of test piece still is equipped with the pond, and the water pump is connected to the pond, injects the salt solution that salt content is the same with the sea water in the pond, and loading water tank, test piece and pond top are equipped with the device that keeps off the rain that can shelter from the rainwater.
Furthermore, the loading head is a solid round steel column and is welded at the bottom of the loading water tank.
Become the nature of width of cloth load down component and expose experimental system, the nature that includes a plurality of becomes the width of cloth load down component exposes experimental apparatus, still include water storage device, a controller, the water supply pump, the drainage water pump, main inlet channel and main outlet conduit, the inlet tube of every loading water tank all connects in main inlet channel, the outlet pipe of every loading water tank all connects in main outlet conduit, main inlet channel and main outlet conduit all communicate with water storage device, the water supply pump sets up on main inlet channel, the drainage water pump sets up on main outlet conduit, the water supply pump, the drainage water pump, inlet solenoid valve and outlet solenoid valve are connected with controlling means electricity.
Furthermore, the natural exposure experimental device of the members under the variable amplitude load is arranged in a rectangular array.
A natural exposure experiment method of a component under variable amplitude load comprises the following steps of firstly setting a variable amplitude load spectrum of a multistage ladder, and adopting a method for measuring deformation and stress of a test piece in stages: in the initial stage of the natural exposure experiment, according to the duration of each load step, a method of ensuring that the test is carried out once within the action time of each load step and continuously measuring for two months is adopted; after two months, according to the change rule of air temperature and humidity, the deformation and stress conditions of the test piece are measured by adopting a method of measuring once at the time point of the lowest air temperature and the time point of the highest air temperature every day, and the physical parameters of stress, strain, displacement, temperature, humidity, salinity and the like at the time of measurement are recorded.
Further, the setting of the variable amplitude load is that load data automatically collected by a manual or detection system is adopted according to the load born by actual equipment or a structure, a damage equivalence principle is applied, a plurality of small loads are equivalent to a large load with equal damage quantity caused to the equipment or the structure to form an equivalent sequence consisting of the large load, then the autocorrelation number or the power spectral density of the equivalent load sequence is calculated by adopting a probability analysis method, the probability distribution is checked, so that a probability distribution function and an autocorrelation function or a power spectral density function of the equivalent load sequence are obtained, then the functions are input into commercial software or a self-programming program with a random process simulation function for numerical simulation, a typical load spectrum which has the same probability distribution and the autocorrelation number or the power spectral density and can reflect the characteristics of the actual load is obtained, and then the maximum sample capacity, the minimum sample capacity, the maximum load data and the maximum load data are obtained according to the variable amplitude load data, And finally, determining the size and frequency of each level of load borne by the test piece by adopting a method that the actual structure is equivalent to the load borne by the test piece (such as bending moment equivalent).
The load applying, monitoring and controlling method includes programming the load to be applied to the test piece, i.e. the variable amplitude load spectrum, into the control software, sending out digital signal by the controller to instruct the water supply pump, the water draining pump, the water inlet solenoid valve and the water outlet solenoid valve to start for loading, monitoring the load by the liquid level sensor and sending out control signal to the controller, and sending out command by the controller to make the water supply pump, the water draining pump, the water inlet solenoid valve and the water outlet solenoid valve work.
In summary, the present invention has the following advantages:
1) the natural exposure experiment device and the system for the component under the variable amplitude load can realize the natural exposure experiment of the component under the coupling/combined action of various environments and the variable amplitude load, and have good universality and wide application range;
2) the natural exposure experiment device and the system for the component under the variable amplitude load can simultaneously carry out natural exposure experiments under the coupling/combined action of the same environment and load on a plurality of test pieces, and can also simultaneously carry out natural exposure experiments under the coupling/combined action of the same environment and different load spectrums on different test pieces, so that the long-term mechanical properties of the test pieces under the interaction of the same or different load spectrums and natural exposure environments can be conveniently analyzed;
3) the natural exposure experimental device and the system for the component under the variable amplitude load have simple and reasonable configuration and layout, and main components and elements have excellent rigidity, strength, stability, reliability and durability, and have the characteristics of convenience in installation and maintenance, low cost and the like.
4) The natural exposure experimental device and the natural exposure experimental system for the component under the variable amplitude load can solve the problems that the variable amplitude load is difficult to control accurately in long-term experiments, and the long-term maintenance of experimental conditions, equipment and sites is difficult and the like.
5) The method for setting the multi-step variable amplitude load is determined by reasonably simplifying the load spectrum borne by equipment, a structure or a member in the actual service process, and has the advantages of same probability statistical characteristics of the load, easiness in simulation and compilation, convenience in continuous measurement, accurate application and control in the long-term experiment process and the like. The variable amplitude load of the invention can reflect the actual bearing condition of important equipment or important engineering structures in the fields of aerospace, land traffic, civil construction, ships, ocean engineering, water conservancy and hydropower, ports, wind power generation, engineering machinery and the like.
6) The natural exposure experimental method of the member under the variable amplitude load has the characteristics of being capable of flexibly changing according to the deformation and stress change rule of the test piece caused by the change of the environment and the load, and is a short-term and long-term combined measuring method, so that the data of the deformation and the stress of the test piece changing along with the change of the environment and the load can be completely, timely, continuously and accurately captured in a long-term manner, and the processing workload of large data can be avoided.
Drawings
FIG. 1 is a schematic structural diagram of an example of a subtropical land environment of a natural exposure experimental device of a component under variable amplitude load;
FIG. 2 is a schematic structural view of another angle of an example of a subtropical land environment of the natural exposure experimental facility for a component under variable amplitude load according to the present invention;
FIG. 3 is a schematic structural diagram of an environment example of a subtropical sea wave splashing zone of the natural exposure experimental device of the component under variable amplitude load;
FIG. 4 is a schematic structural diagram of another angle of an environment example of a subtropical sea wave splashing zone of the natural exposure experimental device of the component under variable amplitude load;
FIG. 5 is a schematic structural diagram of a natural exposure experimental system of a component under variable amplitude load;
FIG. 6 is a step amplitude load spectrum of a natural exposure experiment of a member under variable amplitude load in accordance with an embodiment of the present invention.
Wherein fig. 1 to 5 include:
1-loading a water tank; 2-a loading head; 3-testing a sample; 4-a liquid level sensor; 51-water inlet electromagnetic valve; 52-water outlet electromagnetic valve; 61-water supply pump; 62-a drainage pump; 7-water inlet pipe; 8-water outlet pipe; 9-a water tower; 10-digital strain gauge; 11-a displacement meter; 12-a ground beam; 131-a main water inlet pipe; 132-a main outlet conduit; 14-a controller; 15-a water pool; 16-a rain shield; 17-cable.
Detailed Description
The present invention will be described in further detail below.
Examples 1,
As shown in fig. 1 to 2, the natural exposure experimental device, system and method for the member under variable amplitude load comprises: subtropical zone environment setting, natural exposure experiment device, natural exposure experiment system and natural exposure experiment method. The subtropical environment is a subtropical land environment.
The natural exposure experimental device of the component under the variable amplitude load comprises a plurality of strip-shaped test pieces, two parallel ground beams, a loading water tank and a control device, the test pieces are placed on the two ground beams, the distance between the two ground beams is matched with the length of the test pieces, a digital display type strain gauge and a displacement meter are arranged at the middle position of the bottom of the test piece, the loading water tank is arranged above the test pieces, two parallel loading heads are arranged between the loading water tank and the test pieces, a liquid level sensor is arranged at the bottom of the inner side of the loading water tank, the loading water tank is provided with a water inlet pipe and a water outlet pipe, a water inlet electromagnetic valve is arranged on the water inlet pipe, and a water outlet electromagnetic valve is arranged on the water outlet pipe.
The loading head is a cylindrical loading head, and line contact is formed between the loading head and the test piece.
One side of the ground beam facing the test piece is a cylindrical surface.
The loading head is a solid round steel column and is welded with the loading water tank.
Become the nature of width of cloth load down component and expose experimental system naturally, the nature that includes a plurality of becomes the width of cloth load down component exposes experimental apparatus naturally, still include water storage device (water tower), a controller, the water supply pump, the drainage water pump, main inlet channel and main outlet conduit, every loading water tank's inlet tube all connects in main inlet channel, every loading water tank's outlet pipe all connects in main outlet conduit, main inlet channel and main outlet conduit all communicate with water storage device, the water supply pump sets up on main inlet channel, the drainage water pump sets up on main outlet conduit, the water supply pump, the drainage water pump, inlet solenoid valve and outlet solenoid valve are connected with controlling means electricity.
The natural exposure experimental device of the components under the variable amplitude load is arranged in a rectangular array.
A natural exposure experiment method of a component under variable amplitude load adopts a method for measuring deformation and stress of a test piece in stages: firstly, setting a variable amplitude load spectrum of a plurality of stages of steps, and adopting a method for ensuring that the test is performed once within the action time of each load step and the measurement is performed continuously for two months according to the duration time of each load step at the initial stage of a natural exposure experiment; after two months, according to the change rule of air temperature and humidity, the deformation and stress conditions of the test piece are measured by adopting a method of measuring once at the time point of the lowest air temperature and the time point of the highest air temperature every day, and the physical parameters of stress, strain, displacement, temperature, humidity, salinity and the like at the time of measurement are recorded.
The variable amplitude load is set by adopting load data automatically collected by a manual or detection system according to the load born by actual equipment or a structure and applying a damage equivalent principle to enable a plurality of small loads to be equivalent to a large load with equal damage quantity caused to the equipment or the structure to form an equivalent sequence consisting of the large load, then calculating the autocorrelation number or power spectral density of the equivalent load sequence by adopting a probability analysis method and checking the probability distribution of the equivalent load sequence so as to obtain a probability distribution function and an autocorrelation function or a power spectral density function of the equivalent load sequence, then inputting the probability distribution function and the autocorrelation function or the power spectral density function into commercial software or a self-programming program with a random process simulation function for numerical simulation to obtain a typical load spectrum which has the same probability distribution and the autocorrelation number or the power spectral density and can reflect the characteristics of the actual load, and then testing frequency according to the minimum sample capacity, test piece deformation and stress of the load data, dividing the load simulation spectrum into intervals according to the number of steps to be drawn of the variable amplitude load, taking the average value of each interval as the load amplitude, generating the variable amplitude load spectrum of the multistage steps as shown in fig. 6, and finally determining the size and frequency of each stage of load borne by the test piece by adopting a method that the actual structure is equivalent to the load borne by the test piece (such as bending moment equivalent).
The load applying, monitoring and controlling method includes compiling the load to be applied to the test piece, i.e. the variable amplitude load spectrum, into the control software, and sending out the numerical signal with the controller to command the water supplying pump, the water draining pump, the water inlet solenoid valve and the water outlet solenoid valve to start to realize the loading. The load is monitored by the liquid level sensor and sends a control signal to the controller, and then the controller sends an instruction to enable the water supply pump, the water drainage pump, the water inlet electromagnetic valve and the water outlet electromagnetic valve to work.
The natural exposure experimental device of the component under the variable amplitude load comprises a loading head 2 for loading a test piece 3, a loading water tank 1 and a ground beam 12. Every two test pieces 3 are placed on the ground beam 12 in parallel, and the weight of the loading water tank 1 and the liquid filled in the loading water tank is applied to the test pieces 3 through the loading head 2, so that the force is the same as the gravity direction. The liquid transmission and storage system is used for providing and adjusting the amount of water to the loading water tank and comprises a water inlet pipe 7, a water outlet pipe 8, a water inlet electromagnetic valve 51, a water outlet electromagnetic valve 52, a water supply water pump 61, a drainage water pump 62 and a water tower 9, wherein a main water inlet pipe 131 and a main water outlet pipe 132 are respectively connected with the water inlet pipe 7, the water outlet pipe 8 and the water tower 9 of the loading water tank 1. The testing device comprises a liquid level sensor 4, a displacement meter 11 and a digital display type strain gauge 10, wherein the liquid level sensor 4 is positioned at the bottom of the inner side wall of the loading water tank 1 and used for measuring water pressure, the displacement meter 11 is positioned on the lower surface of the middle part of the test piece 3 and used for testing the deflection (vertical displacement) of the test piece 3, and the digital display type strain gauge 10 is positioned on the lower surface (tension part) of the middle part of the test piece 3 and used for measuring the stress and deformation conditions of the tension part of the test piece 3. The control device comprises a controller 14, and the controller 14 is electrically connected with a water inlet electromagnetic valve 51, a water outlet electromagnetic valve 52, a water supply water pump 61 and a water discharge water pump 62. The water inlet pipe 7 and the water outlet pipe 8 of each loading water tank 1 are respectively provided with 1 water inlet electromagnetic valve 51 and 1 water outlet electromagnetic valve 52 for controlling the water inlet and the water discharge of the loading water tank 1, the water pumps are divided into a water supply water pump 61 and a water discharge water pump 62 which are respectively connected with a main water inlet pipeline 131 and a main water outlet pipeline 132 for the water inlet and the water discharge of each loading water tank 1, and the controller 14 is positioned in an indoor monitoring room and is connected with the liquid level sensor 4, the water inlet electromagnetic valve 51, the water outlet electromagnetic valve 52, the water supply water pump 61 and the water discharge water pump 62 through a cable 17 for controlling the water supply and the water discharge of each loading water tank 1 so as to ensure that the weight of each loading water tank 1 is consistent with the amplitude load spectrum.
As shown in fig. 1, the number of the ground beams 12 is more than two, and the distance between every two ground beams 12 is adapted to the span of the test piece 3. The ground beam 12 is designed into a strip-shaped Reinforced Concrete (RC) component with the top being semicircular, the length being arbitrary (set according to the size of an experimental site), the height being 20-30 cm and the width being 20-30 cm, and the component is arranged on the smooth cement ground, and the test piece 3 can be stably placed. The ground beam 12 plays a role of a support, can prevent accumulated water from soaking the test piece 3, and is convenient for measuring the stress and deformation of the test piece 3. A plurality of groups of test pieces 3 are placed in parallel above the ground beam 12 to form a plurality of loading devices, each loading device is provided with two test pieces 3, two loading heads 2 and one loading water tank 1, and the distance between the two test pieces 3 is matched with the width of the bottom plate of the loading water tank 1 and the length of the loading heads 2.
The loading head 2 is a solid round steel column, the axial direction of the loading head 2 is arranged along the width direction of the test piece 3 and the loading water tank 1, the length of the loading head 2 is the same as the width of the bottom plate of the loading water tank 1, the bottom of the loading head is in line contact with the upper surface of the test piece, and the upper part of the loading head is welded on the outer surface of the bottom plate of the loading water tank 1. Two parallel loading heads 2 are welded at the bottom of each loading water tank 1, the distance between the two loading heads 2 is equal to the trisection of the span of the test piece 3, and a four-point bending loading form is formed.
The loading water tank 1 shown in fig. 1 is a rectangular container, one loading water tank 1 is placed on every two test pieces 3, the volume of the loading water tank 1 is set according to the experimental load, and a bottom plate and side plates of the loading water tank do not deform obviously under the full load and do not turn over under the action of strong wind. The top plate of the loading water tank 1 is set as a cover plate which can be conveniently opened; the bottom plate and the side plate are provided with reinforcing ribs, wherein the distance between the two reinforcing ribs in the middle of the bottom plate is the same as the distance between the two four-point bent loading heads 2, and the two reinforcing ribs are connected with the loading heads 2; the side plate is provided with a water inlet and a water outlet which are respectively connected with a water inlet pipe 7 and a water outlet pipe 8.
The water tower 9 shown in fig. 5 is a rectangular thick-walled container made of weather-resistant structural steel, and the size of the container is set according to the height of each loading water tank 1 (to ensure a certain water supply pressure), the total amount of water required to be adjusted in the experiment and the like. The top of the water inlet pipe is provided with a water inlet and a water outlet which are connected with a main water inlet pipe 131, a main water outlet pipe 132, a water supply pump 61 and a water drainage pump 62, and the bottom plate and the side plates are provided with reinforcing ribs. The water tower 9 is placed on a flat cement site, and does not deform obviously in the operation process.
The main components of the controller 14 include a Central Processing Unit (CPU) for programming and communicating with the touch screen and an output module, a digital output module for controlling the opening and closing of the water inlet solenoid valve 51 and the water outlet solenoid valve 52, a PLC analog acquisition module for acquiring sensor signals, and an ac contactor for controlling the on and off of the water supply pump 61, the water discharge pump 62, and an air switch.
The exposure experiment method of the component under variable amplitude load in the subtropical natural environment comprises the following steps:
1) and setting the amplitude variation load. The method comprises the steps of obtaining a typical load spectrum of a bridge structure which has the same statistical characteristics and can be numerically simulated by adopting load data automatically acquired by a manual or detection system and applying a damage equivalent principle through probability statistical analysis, and simplifying the typical load spectrum into a multilevel step variable amplitude load spectrum. Then, the method that the actual structure is equivalent to the load borne by the test piece 3 is adopted to determine the size and frequency of each level of load borne by the test piece 3.
2) Test piece 3 was designed and fabricated. According to the shape, the size and the stress condition of an actual bearing member and the experimental conditions of a natural exposure experimental field, the test piece 3 is designed according to a certain shrinkage ratio, and a batch of test pieces 3 are manufactured according to relevant standards/regulations.
3) Setting of natural exposure environment. And setting the environment as the subtropical land environment according to the actual service environment of the subtropical zone where the component is located. For subtropical land environment, the reinforced concrete ground beam 12 for placing the test piece 3 is only required to be arranged on an outdoor open-air experimental site of the subtropical zone.
4) And manufacturing a loading device. Firstly, according to the type and the size of a group of two test pieces 3, two loading heads 2 and a loading water tank 1 are made of stainless steel, according to two loading positions of the four-point bending test piece 3, the two loading heads 2 are respectively welded at the loading positions on the bottom surface of the loading water tank 1 in a line contact mode, the loading heads 2 are fixedly connected with the loading water tank 1 to form a group of loading devices, a water inlet and a water outlet are formed in one side wall of the loading water tank 1, and a liquid level sensor 4 is installed below the water outlet. Then, the above process is repeated to make several groups of the same loading devices according to the number of groups of the test pieces 3.
5) A water tower 9 is produced. The size of the water tower 9 is set according to the number and height of the loading water tanks 1, the total water amount required to be adjusted in an experiment and the like, and the water tower 9 is made of a stainless steel plate according to the principle that a bottom plate and side plates of the water tower are not deformed when the water tower is fully loaded and the height of the water tower 9 is higher than that of the loading water tank 1 after installation. The bottom plate and the side plate are provided with reinforcing ribs, and the top plate is provided with a water inlet and a water outlet so as to be connected with a water inlet pipe 7 and a water outlet pipe 8.
6) The test piece 3 is mounted. Firstly, a group of two test pieces 3 are placed on a preset ground beam 12 in parallel, the distance between the two test pieces 3 is set according to the width of the loading water tank 1, and the outer side surface of each test piece 3 is flush with or slightly close to the outer side surface of the loading water tank 1, so that the test pieces 3 can be exposed in the natural environment, and the loading head 2 and the loading water tank 1 can be stably placed on the group of two test pieces 3. Then, the digital display type strain gauge 10 and the mounting displacement gauge 11 are attached to the mid-span bottom of the test piece 3. The above installation procedure was repeated for the other sets of test pieces.
7) And installing a water storage and supply and transmission system. Firstly, the water tower 9 is installed and placed on a flat cement ground with a higher terrain, then a PVC thick-wall main water inlet pipeline 131 and a main water outlet pipeline 132 with proper sizes are selected according to the requirements of water supply, water discharge and water supply and discharge time of an experimental system, and the water outlet and the water inlet of the water tower 9 are respectively connected with the water inlet pipe 7 and the water outlet pipe 8 of each loading water tank 1 through the main water inlet pipeline 131 and the main water outlet pipeline 132.
8) And installing a control device. A CPU, a touch screen, an output module, a collection module, an alternating current contactor and the like are installed and integrated in a control room to form a controller 14, and the controller is connected with an air switch, a pressure transmitter, a water supply pump 61, a water drainage pump 62, a water inlet electromagnetic valve 51, a water outlet electromagnetic valve 52 and a liquid level sensor 4 through a cable 17. Then control, data acquisition and post-processing software is input into a CPU in the controller 14, and finally the variable amplitude load spectrum is input into a control program.
9) And (5) load measurement and control. The load applied to the test piece 3 is measured by the liquid level sensor 4, and the load is controlled by the water level (water pressure) of the loading water tank 1. When the load of a certain step is adjusted to the target load, the liquid level sensor 4 sends a signal to the controller 14, and the control system sends an instruction to the water supply pump 61, the water discharge pump 62, the water inlet electromagnetic valve 51 and the water outlet electromagnetic valve 52, so that the water supply pump 61 and the water discharge pump 62 stop running, and the water inlet electromagnetic valve 51 and the water outlet electromagnetic valve 52 are closed. The target load is load data automatically collected by a manual or detection system according to the stress condition of a member in an actual structure, a damage equivalence principle is applied, a plurality of small loads are equivalent to a large load with equal damage quantity caused to equipment or a structure, an equivalent sequence consisting of the large load is formed, then the autocorrelation number or the power spectral density of the equivalent load sequence is calculated by adopting a probability analysis method, the probability distribution is checked, so that the probability distribution function and the autocorrelation function or the power spectral density function of the equivalent load sequence are obtained, then the functions are input into commercial software or a self-programming program with a random process simulation function for numerical simulation, a typical load spectrum which has the same probability distribution and the autocorrelation number or the power spectral density and can reflect the characteristics of the actual load is obtained, and then the test frequency is tested according to the minimum sample capacity, the deformation and the stress of the load data, dividing the load simulation spectrum into intervals according to the number of steps of the variable amplitude load, taking the average value of each interval as a load amplitude value, generating a variable amplitude load spectrum of multiple steps, finally determining the size and frequency of each level of load borne by the test piece 3 by adopting a method that the actual structure is equivalent to the load borne by the test piece 3 (such as bending moment equivalent), converting the load spectrum of an actual component into the load spectrum of the test piece 3, and compiling the load spectrum of the test piece 3 into the variable amplitude load spectrum (target load spectrum) for the natural exposure experiment.
10) And (5) long-term testing. The test piece 3 can deform under the coupling/combined action of the natural exposure environment and the variable amplitude load, and the deformation of the test piece 3 can cause the stress change of the test piece in turn. Therefore, in order to find out the change rule of the long-term mechanical property of the test piece 3 under the coupling/combined action of the natural exposure environment and the variable amplitude load, the test precision is ensured, and the influence of non-environment and non-external force is reduced as much as possible. For the concrete test piece 3, on one hand, the invention puts the Reinforced Concrete (RC) test piece 3 which is well maintained in a room for one year and then carries out a natural exposure experiment so as to reduce the influence of the shrinkage and creep of the concrete on the long-term mechanical property of the concrete as much as possible. On the other hand, no matter what material the test piece 3 is made of, the method for measuring the deformation and the stress of the test piece 3 by stages is adopted according to the step number of the load spectrum: in the initial stage of the natural exposure experiment, according to the duration time of each load step, a method of ensuring that the test is carried out once within the action time of each load step and continuously measuring for two months is adopted; after two months, the deformation and stress conditions of the test piece 3 are measured by adopting a method of measuring once at the time points of the lowest temperature and the highest temperature every day according to the change rule of the temperature and the humidity. During measurement, the physical parameters of stress, strain, displacement, temperature, humidity, salinity and the like at the time are recorded. The deflection of the test piece 3 is tested by a displacement meter 11 positioned at the middle bottom of the test piece 3, the strain is tested by a digital display strain meter 10 adhered to the tension part of the test piece 3, the stress of the test piece 3 is measured by a liquid level sensor 4, and the temperature, the humidity and the salinity are respectively measured by a temperature hygrometer and a salinity meter.
The natural exposure experiment method and the device can be used for natural exposure experiments of Reinforced Concrete (RC) structural members, steel structural members, composite materials, fiber reinforced composite (FRP) reinforced RC structural members, FRP reinforced steel structural members, steel-concrete combined structural members and load-bearing members consisting of other materials of buildings/structures such as bridges, tunnels, ports, wharfs, roads, dams, venues, ships, deep sea platforms, automobiles, aircrafts and the like.
In general, the present invention has the following advantages:
the natural exposure experimental device and the system for the component under the variable amplitude load have the following advantages:
1) the natural exposure experiment device and the system for the component under the variable amplitude load can realize the natural exposure experiment of the component under the coupling/combined action of various environments and the variable amplitude load, and have good universality and wide application range;
2) the natural exposure experiment device and the system for the component under the variable amplitude load can simultaneously carry out natural exposure experiments under the coupling/combined action of the same environment and load on a plurality of test pieces 3, and can also simultaneously carry out natural exposure experiments under the coupling/combined action of the same environment and different load spectrums on different test pieces 3, so that the long-term mechanical properties of the test pieces under the coupling interaction of the same or different load spectrums and the natural exposure environment can be conveniently analyzed;
3) the natural exposure experimental device and the system for the component under the variable amplitude load have simple and reasonable configuration and layout, and main components and elements have excellent rigidity, strength, stability, reliability and durability, and have the characteristics of convenience in installation and maintenance, low cost and the like.
4) The natural exposure experimental device and the natural exposure experimental system for the component under the variable amplitude load can solve the problems that the variable amplitude load is difficult to measure and control accurately in long-term experiments, and the experimental conditions, equipment and sites are difficult to maintain for a long time.
The natural exposure experimental method of the component under the variable amplitude load has the following advantages:
1) the method for setting the multi-step variable amplitude load in the experimental method is determined after reasonably simplifying the load spectrum borne by the equipment, the structure or the member in the actual service process, and has the advantages of same statistical characteristics of the load, easiness in simulation and compilation, convenience in continuous measurement, accurate application and control in the long-term experimental process and the like. The variable amplitude load of the invention can reflect the actual bearing condition of important equipment or important engineering structures in the fields of aerospace, land traffic, civil construction, ships, ocean engineering, water conservancy and hydropower, ports, wind power generation, engineering machinery and the like.
2) The natural exposure experimental method of the member under the variable amplitude load has the characteristics of being capable of flexibly changing according to the deformation and stress change rule of the test piece 3 caused by the change of the environment and the load, and is a short-term and long-term combined measuring method, so that the data of the deformation and the stress of the test piece 3 changing along with the change of the environment and the load can be completely, real-timely, long-term, continuously and accurately captured, and the processing workload of large data can be avoided.
Example 2
The main apparatus and method of this embodiment are the same as embodiment 1, and the main difference is that:
as shown in fig. 3 and 4, the natural exposure environment in this embodiment is the subtropical ocean wave splash zone environment. The lower part of test piece 3 still is equipped with pond 15, and the water pump is connected to pond 15, pours into in the pond 15 salt solution that salt content is the same with the sea water, and loading water tank 1, test piece 3 and pond 15 top are equipped with the device 16 that keeps off the rain that can shelter from the rainwater. The pool 15 is a rectangular RC structure with any length (set according to the size of an experimental site), the width equal to the distance between the 2 ground beams 12 and the depth of 1500-2000 mm, the surface of the pool needs to be subjected to water seepage prevention treatment, two long sides of the pool are constructed according to the requirements of the ground beams 12, and the pool is provided with a water discharging device such as a water pump. The water pool 15 is used for configuring artificial seawater according to the variation condition of seawater salinity in subtropical coastal areas, and a loading device is arranged above the water pool 15. The discharge of the artificial seawater is completed by a matched water pump. The rain shelter 16 (rain shed) is an overhead pitched roof structure made of weather-proof and light-transmitting PVC and the like, and is erected above the water pool 15 by adopting a stainless steel frame so as to prevent rainwater from flowing into the water pool 15 and reduce the salt concentration of artificial seawater.
In the specific embodiment, the exposure experiment method and the device of the member under the variable amplitude load in the subtropical zone natural environment are adopted, a carbon fiber reinforced composite material (CFRP) Reinforced Concrete (RC) beam is taken as a test piece 3, the environment of a subtropical zone wave splashing area is taken as a typical natural environment of the subtropical zone, and then the natural exposure experiment of the member under the variable amplitude load is carried out according to the following steps:
(1) test piece 3 was designed and fabricated. According to relevant specifications, a test piece 3 is designed by a common reinforcing member 'CFRP reinforced RC simple beam' of an RC bridge in subtropical regions according to a certain shrinkage ratio. Wherein, the RC beam has the size of 1850mm in length, 100mm in width and 200mm in height, and the span is 1600 mm; the concrete is C30; the main reinforcements are phi 10 II-grade reinforcements, the erection reinforcements and the stirrups are phi 8I-grade reinforcements, and the reinforcement ratio is 0.981%; CFRP is CFRP prepreg woven by T700-12k carbon fiber yarns, such as carbon fiber sheets (CFL), with a calculated thickness of 1560mm length × 100mm width × 0.23 mm; and (3) symmetrically sticking the CFL to the bottom of the RC beam by adopting ultrahigh-strength epoxy resin A and B glue.
For the production of the test piece 3, a steel reinforcement cage is first tied, a strain gauge is attached to the lower edge of the main reinforcement, concrete is then poured, the steel reinforcement cage is left for 1 day, then demolded and cured for 28 days, and then left indoors for 1 year, and then a carbon fiber sheet is attached.
(2) Designing and checking a main device.
1) Design of the loading water tank 1: in order to facilitate statistical analysis of long-term mechanical properties and the like of the test piece 3, each loading water tank 1 (containing liquid) is determined as the load of 2 test pieces 3; according to the size of a test piece and the constant load of an actual component, the loading form of the test piece 3 in a natural exposure experiment is determined to be four-point bending, then according to a bending moment equivalent principle, after the stress and deformation of the loading water tank 1 are calculated in a trial mode, the size of the loading water tank 1 is determined as follows: 2000mm long × 800mm wide × 1200mm high; the materials, shapes and dimensions of the constituent parts of the loading reservoir 1 are finally determined as follows:
a frame: in order to ensure the strength and rigidity of the loading water tank 1, a frame type structure is formed by adopting square steel pipes. The frame sizes are respectively: the length l is 2000mm, the width w is 800mm, and the height h is 1200 mm. The square steel tube is made of 201 stainless steel, the section size of the square steel tube is 30mm multiplied by 30mm, and the thickness of the square steel tube is 2 mm.
A bottom plate: is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, and has the size of 2000mm long multiplied by 800mm wide. Two reinforcing ribs are symmetrically arranged at the middle of the bottom surface at a distance of l 1-533.3 mm along the length direction, 1 reinforcing rib is arranged at the middle position along the width direction, and the material and the cross section dimension of the reinforcing ribs are the same as those of the square steel pipe, so that the rigidity of the bottom plate is enhanced and the load is borne.
Side plates: the loading water tank is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, two side plates in the length direction of the loading water tank 1 are 2000mm long and 1200mm high, and the two reinforcing ribs are arranged along the height direction; the two side plates in the width direction of the loading water tank 1 are 800mm wide and 1200mm high, and are provided with 1 reinforcing rib along the width direction. The reinforcing rib adopts the stainless steel square steel pipe, and the material and the section size of the reinforcing rib are the same as those of the square steel pipe.
Cover plate: is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, and the size is 2000mm long multiplied by 800mm wide. 1 reinforcing rib is arranged along the length direction of the loading water tank 1, 2 reinforcing ribs are arranged in the width direction at equal intervals, and the material and the size of the reinforcing ribs are the same as those of the stainless steel square steel pipe.
2) Design of a water tower 9: the water tower 9 is used for supplying water and storing water for the whole experimental system and forming certain water pressure for each loading water tank 1. For the present embodiment, the loading water tanks 1 are provided with 15 loading water tanks according to the amplitude of variation (a)Ladder) load spectrum and considering the dead load of the bridge structure, the maximum water quantity required to be regulated by the whole system is 11.52m 3 . For this purpose, the water tower 9 is dimensioned: 3660mm long by 1500mm wide by 2150mm high, the materials, shapes and dimensions of the constituent parts are determined as follows:
a frame: in order to ensure the strength and rigidity of the water tower 9, a frame type structure is formed by square steel pipes. The frame sizes are respectively: the length l is 3660mm, the width w is 1500mm, and the height h is 2150 mm. The square steel pipe is made of 201 stainless steel, the section size of the square steel pipe is 30mm multiplied by 30mm, and the thickness of the square steel pipe is 2 mm.
A bottom plate: is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, and has the size of 3660mm long multiplied by 1500mm wide. 3 reinforcing ribs are arranged on the bottom surface at equal intervals along the length direction, 2 reinforcing ribs are arranged at equal intervals along the width direction, and the material and the cross section dimension of the reinforcing ribs are the same as those of the square steel pipe so as to enhance the rigidity of the bottom plate.
Side plates: the water tower is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, the two side plates in the length direction of the water tower 9 are 3660mm long and 2150mm high, 2 reinforcing ribs are arranged in the height direction at equal intervals, and 3 reinforcing ribs are arranged in the length direction at equal intervals; the dimension of 2 side plates in the width direction of the water tower 9 is 1500mm wide multiplied by 2150mm high, 1 reinforcing rib is arranged along the width direction, and 2 reinforcing ribs are arranged along the height direction at equal intervals. All the reinforcing ribs are made of the stainless steel square steel tubes, and the materials and the cross-sectional dimensions of the reinforcing ribs are the same as those of the stainless steel square steel tubes.
Cover plate: is made of a 201 stainless steel plate with the thickness of 2mm and provided with reinforcing ribs, and has the size of 3660mm long multiplied by 1500mm wide. 2 reinforcing ribs are arranged along the length direction of the water tower 9 at equal intervals, 1 reinforcing rib is arranged along the width direction, and the material and the size of the reinforcing ribs are the same as those of the stainless steel square steel pipe. The cover plate is provided with a water inlet and a water outlet, which are connected with a main water inlet pipe 131 and a main water outlet pipe 132.
3) Checking calculation
And (3) checking the strength: the maximum stress of the bottom plate and the side plate of the loading water tank 1 and the water tower 9 is less than the yield strength (275MPa) of 201 stainless steel under the set load, and the design requirements are met.
Stiffness/deformation checking: addingThe bottom plate and side plate of the water-carrying tank 1 and the water tower 9 are at the set load (the volume of each water-carrying tank 1 is 1.92 m) 3 The volume of the water tower 9 is about 11.8m 3 Maximum deformation under/maximum load) is less than 1mm, and the design requirements are met.
And (4) checking and calculating the stability: the loading water tank 1 is erected on the 2 test pieces 3, so that whether the test pieces overturn under the action of strong wind (12-level typhoon) needs to be checked. The result of the checking calculation shows that when the capacity of the loading water tank 1 is more than 60%, the loading water tank cannot overturn under the action of strong wind and has good stability.
4) Other major components/components are designed and checked.
And (3) loading the head 2: the material is SUS304, and the sizes are as follows: the diameter phi 1 is 30mm, and the length L is 800 mm.
The ground beam 12: the material is reinforced concrete, and the concrete is marked as C30. The radius of the top of the ground beam 12 is 300mm, the height is 300mm, the width is 300mm, and the length is two (10m and 5m), wherein 5m is arranged on the side of the water pool 15, and the rest is 10 m.
A water pool 15: the main body structure is reinforced concrete, the concrete is marked with C30, and the main body structure is subjected to seepage-proofing and corrosion-proofing treatment. The size of the pool 15 is: the artificial seawater with the length of 5000mm, the width of 1300mm and the depth of 1500mm is kept at the depth of 1200mm during the experiment, and the salinity is 3 percent.
Rain guard 16 (rain shed): the canopy 16 is sized as follows: 5200 multiplied by the width multiplied by the height multiplied by 1600mm, wherein the bracket material is SUS304, the section size is 50 multiplied by 50mm, and the wall thickness is 3mm square steel; the shed roof material is transparent PVC, and the thickness is 5 mm.
And (4) checking and calculating results: the strength of each part/component is enough, and the deformation of each part/component is within the elastic range, so that the design requirement is met.
(3) And (5) building a natural exposure experimental field. A flat ground with the length of 18000mm and the width of 12000mm is circled in a campus of southern science and engineering of Guangzhou China, and an experimental field is built according to the following steps:
1) after leveling, pouring concrete with the thickness of 200 mm;
2) respectively pouring ground beams 12 with the lengths of 10000mm and 5000mm along the length direction at intervals of 1600 mm;
3) constructing a water pool 15 between 2 ground beams 12 with the length of 5000 mm;
4) a rain shield 16 (canopy) is constructed above the pool 15;
5) and constructing a fence at the periphery of the experimental site.
(4) And (3) exposing the natural environment of the subtropical wave splashing region of the component under variable amplitude load. The method comprises the following steps:
1) and setting the amplitude variation load. The typical load spectrum of the RC bridge structure which has the same statistical characteristics and can be numerically simulated is obtained by adopting load data automatically collected by a manual or detection system and applying a damage equivalence principle through statistical analysis, and then the typical load spectrum is simplified into a multi-step variable amplitude load spectrum. Then, the method that the actual structure is equivalent to the load borne by the test piece 3 is adopted to determine the magnitude and frequency of the loads at all levels borne by the test piece 3. In the embodiment, the dead load of the RC bridge member accounts for 60% of the total load, the vehicle load accounts for 40%, and the maximum value of the total load is controlled to be lower than the cracking load of the concrete. The variable amplitude (vehicle) load spectrum is a step load spectrum, as shown in figure 6, 1 period is 7 days, 28 steps are arranged in each period, and the action time of each step is determined according to the action frequency proportion of each load amplitude in the original load spectrum.
2) Manufacturing a loading water tank 1, a loading head 2, a water tower 9, a test piece 3, a controller 14 and other devices; purchasing a water pump, an electromagnetic valve, a pipeline, a liquid level sensor 4, a digital display type strain gauge 10, a displacement meter 11 and the like;
3) the loading device was constructed as shown in figure 1. Firstly welding two loading heads 2 on a bottom plate of a loading water tank 1 according to four-point bending loading positions, then placing two test pieces 3 on a ground beam 12 beside a water pool 15 and right above the water pool 15, and then placing 1 loading water tank 1 with the loading heads 2 on the two test pieces 3 to enable the loading heads 2 to be in line contact with the upper surfaces of the test pieces 3 to form a group of loading devices. Then, building other groups of loading devices according to the method;
4) a rain shield 16 (rain shed) is built up above the basin 15 and the loading device, as shown in fig. 3. The number of rain shelters 16 (rain sheds) is the same as the number of pools 15 and matches the number of loading devices;
5) the water storage and supply and transmission system, the testing device and the control device are installed as shown in figure 5. In holding water supply and transmission system, the pipeline is for resistant time PVC thick wall pipe, divide into two kinds: the water inlet pipeline 131 and the water outlet pipeline 132 are respectively in a size of phi 64 mm; the water inlet pipe 7 and the water outlet pipe 8 which are connected with the loading water tank 1 have the size of phi 32 mm; the water pump is a pipeline centrifugal pump and is divided into a water supply pump 61 and a water discharge pump 62; the electromagnetic valves of the control device are normally closed two-port two-position direct-acting electromagnetic valves which are respectively arranged on the water inlet pipe 7 and the water outlet pipe 8 of each loading water tank 1; the liquid level sensor 4 of the testing device is a universal pressure sensor, is arranged at the lower part of the inner side wall of the loading water tank 1, has the measurement precision of 0.1 percent, and can control the deviation of the liquid level of the system to be less than 1 mm.
6) Artificial seawater with salinity of 3% or 2% or 1% is prepared and injected into the water pool 15, and then the experimental system is started to start the natural exposure experiment.
(5) Long-term stress and deformation test of the test piece 3. A method for measuring the deformation and the stress of the test piece 3 by stages is adopted according to the number of steps of a load spectrum: in the initial stage of the natural exposure experiment, according to the duration time of each load step (see figure 6), a method of ensuring that each load step is tested for 1 time within the action time and continuously measuring for 2 months is adopted; after 2 months, according to the change rule of air temperature and humidity, measuring the deformation and stress conditions of the test piece by respectively measuring for 1 time at the time point of the lowest air temperature and the time point of the highest air temperature every day. During measurement, the physical parameters of stress, strain, displacement, temperature, humidity, salinity and the like at the time are recorded. The deflection of the test piece 3 is tested by a displacement meter 11 positioned at the mid-span bottom of the test piece 3; the strain is tested by a digital display type strain gauge 10 (an external single-string intelligent strain gauge with the measurement precision of 2 mu epsilon) stuck to the tension part of the test piece 3; the stress of the test piece 3 is measured by the liquid level sensor 4; temperature, humidity and salinity were measured by a temperature hygrometer and a salinity meter, respectively.
(6) And controlling the concentration of the seawater. The salinity variation conditions (actually measured data) of the sea areas near the main sea entrances (tiger door, cliff door and knife door) of the Zhujiang are set as follows: 2%, 1%, 2%, 3% and controlled by 1 adjustment per week, i.e. the brine in the basin 15 is replenished once per week and its salinity is measured, when the salinity deviates from the set value, the adjustment is made by adjusting the amount of salt or water until it reaches the set value.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such modifications are intended to be included in the scope of the present invention.

Claims (7)

1. Become natural exposure experimental apparatus of width of cloth load lower component, its characterized in that: the device comprises a plurality of strip-shaped test pieces, two ground beams arranged in parallel, a loading water tank and a control device, wherein the test pieces are placed on the two ground beams, the distance between the two ground beams is adaptive to the length of the test piece, a digital strain gauge and a displacement meter are arranged at the middle position of the bottom of the test piece, the loading water tank is arranged above the test piece, two loading heads arranged in parallel are arranged between the loading water tank and the test piece, a liquid level sensor is arranged at the bottom of the inner side of the loading water tank, the loading water tank is provided with a water inlet pipe and a water outlet pipe, a water inlet electromagnetic valve is arranged on the water inlet pipe, and a water outlet electromagnetic valve is arranged on the water outlet pipe;
the loading water tank is connected with an external water tower through a water pipe, and the water tower is far higher than the loading water tank; the control device controls the water inlet electromagnetic valve and the water outlet electromagnetic valve so as to accurately control the liquid level of the loading water tank; the control device is used for realizing the variable amplitude load loading of the loading water tank on the multistage ladder of the test piece; wherein the external water tower has dimensions of: 3660mm long × 1500mm wide × 2150mm high; the size of the loading water tank is as follows: 2000mm long × 800mm wide × 1200mm high; the loading head is a cylindrical loading head, and the loading head is in line contact with the test piece; the loading head is a solid round steel column and is welded on the bottom surface of the loading water tank.
2. The natural exposure experimental apparatus of a member under variable amplitude load according to claim 1, characterized in that: one side of the ground beam facing the test piece is a cylindrical surface.
3. The natural exposure experimental apparatus of a member under variable amplitude load according to claim 1, characterized in that: the lower part of the test piece is also provided with a water tank which is connected with a water pump, the water tank is filled with salt water with the salt content being the same as that of the seawater, and a rain shielding device capable of shielding rainwater is arranged above the loading water tank, the test piece and the water tank.
4. Become natural exposure experimental system of component under width of cloth load, its characterized in that: the natural exposure experimental device comprises the variable amplitude load lower member as claimed in any one of claims 1 to 3, and further comprises a water storage device, a water supply pump, a water discharge pump, a main water inlet pipeline and a main water outlet pipeline, wherein the control device comprises a controller, a water inlet pipe of each loading water tank is connected to the main water inlet pipeline, a water outlet pipe of each loading water tank is connected to the main water outlet pipeline, the main water inlet pipeline and the main water outlet pipeline are communicated with the water storage device, the water supply pump is arranged on the main water inlet pipeline, the water discharge pump is arranged on the main water outlet pipeline, and the water supply pump, the water discharge pump, the water inlet solenoid valve and the water outlet solenoid valve are electrically connected with the controller.
5. The natural exposure test system for a member under variable amplitude load according to claim 4, wherein: the natural exposure experimental device of a plurality of components under variable amplitude load is arranged in a rectangular array.
6. The natural exposure experimental method of the component under the variable amplitude load is characterized in that: firstly, setting a multi-step variable amplitude load spectrum, and adopting a method for measuring the deformation and the stress of a test piece by stages: in the initial stage of the natural exposure experiment, according to the duration of each load step, a method of ensuring that the test is carried out once within the action time of each load step and continuously measuring for two months is adopted; after two months, measuring the deformation and stress conditions of the test piece by adopting a method of measuring once at the time points of the lowest temperature and the highest temperature every day according to the change rule of the temperature and the humidity, and recording the stress, strain, displacement, temperature, humidity and salinity at the time of measurement;
the variable amplitude load is set by adopting load data automatically collected by a manual or detection system according to the load born by actual equipment or a structure and applying a damage equivalent principle to enable a plurality of small loads to be equivalent to a large load with equal damage quantity caused to the equipment or the structure to form an equivalent sequence consisting of the large load, then calculating the autocorrelation number or power spectral density of the equivalent load sequence by adopting a probability analysis method and checking the probability distribution of the equivalent load sequence so as to obtain a probability distribution function and an autocorrelation function or a power spectral density function of the equivalent load sequence, then inputting the probability distribution function and the autocorrelation function or the power spectral density function into commercial software or a self-programming program with a random process simulation function for numerical simulation to obtain a typical load spectrum which has the same probability distribution and the autocorrelation number or the power spectral density and can reflect the characteristics of the actual load, and then testing frequency according to the minimum sample capacity, test piece deformation and stress of the load data, dividing the load simulation spectrum into intervals according to the number of steps of the variable amplitude load, taking the average value of each interval as the load amplitude, generating the variable amplitude load spectrum of the multistage steps, and then determining the size and frequency of each level of load borne by the test piece by adopting a method that the actual structure is equivalent to the load borne by the test piece.
7. The natural exposure test method of a member under variable amplitude load according to claim 6, characterized in that: the load applying, monitoring and controlling method includes compiling the load to be applied to the test piece, i.e. variable amplitude load spectrum, into the control software, sending out digital signal by the controller, instructing the water supply pump, the water draining pump, the water inlet solenoid valve and the water outlet solenoid valve to work to realize loading, monitoring the load by the liquid level sensor, sending out control signal to the controller, and sending out instruction by the controller to make the water supply pump, the water draining pump, the water inlet solenoid valve and the water outlet solenoid valve work.
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CN115290467B (en) * 2022-08-23 2023-12-01 广东工业大学 Method for representing long-term performance of fiber cloth-concrete interface based on acceleration experiment method
CN116198749B (en) * 2023-05-06 2023-07-25 中国科学院空间应用工程与技术中心 Space material exposure experiment control system and method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110046652A (en) * 2009-10-29 2011-05-06 현대제철 주식회사 device for hot working test
CN102435489A (en) * 2011-09-15 2012-05-02 华南理工大学 Method for carrying out mechanical test under coupling effect of hygrothermal conditions and dynamic load
CN102589993A (en) * 2012-02-09 2012-07-18 东南大学 Method for monitoring overall welded joint fatigue damage of steel bridge deck of highway
CN205844085U (en) * 2016-08-01 2016-12-28 山西省交通科学研究院 A kind of asphalt pavement rut tester of simulated rainfall
CN106644725A (en) * 2017-01-04 2017-05-10 中国水利水电科学研究院 Experimental device and method for long-term performance of concrete beam under coupling action of environment and load
CN107609317A (en) * 2017-10-25 2018-01-19 中国铁道科学研究院铁道建筑研究所 A kind of steel bridge fatigue evaluation load modeling and Fatigue Assessment method
CN109406269A (en) * 2018-09-28 2019-03-01 华南理工大学 Hold the natural exposing experimental provision and method of mount components

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110046652A (en) * 2009-10-29 2011-05-06 현대제철 주식회사 device for hot working test
CN102435489A (en) * 2011-09-15 2012-05-02 华南理工大学 Method for carrying out mechanical test under coupling effect of hygrothermal conditions and dynamic load
CN102589993A (en) * 2012-02-09 2012-07-18 东南大学 Method for monitoring overall welded joint fatigue damage of steel bridge deck of highway
CN205844085U (en) * 2016-08-01 2016-12-28 山西省交通科学研究院 A kind of asphalt pavement rut tester of simulated rainfall
CN106644725A (en) * 2017-01-04 2017-05-10 中国水利水电科学研究院 Experimental device and method for long-term performance of concrete beam under coupling action of environment and load
CN107609317A (en) * 2017-10-25 2018-01-19 中国铁道科学研究院铁道建筑研究所 A kind of steel bridge fatigue evaluation load modeling and Fatigue Assessment method
CN109406269A (en) * 2018-09-28 2019-03-01 华南理工大学 Hold the natural exposing experimental provision and method of mount components

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
过载阶梯谱下CFRP加固RC构件疲劳实验研究;周昊 等;《中国科学》;20150531;第45卷(第5期);第498-502页 *

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