CN-122016203-A - Pipeline wet creep performance experimental device and experimental method

CN122016203ACN 122016203 ACN122016203 ACN 122016203ACN-122016203-A

Abstract

The invention discloses a pipeline wet creep performance experimental device and an experimental method, wherein the experimental device comprises a base unit, a water tank and a loading unit, the base unit comprises a base and a pressure sensor, and the pressure sensor is arranged on the base; the loading unit is provided with a loading end, and the loading end can apply load to the pipeline along the vertical downward direction. The experimental method comprises the following steps of measuring and calculating initial ring stiffness and experimental load of the pipeline, placing the pipeline in a water tank, injecting water into the water tank until the pipeline is completely submerged, applying the experimental load to the pipeline through a loading unit, and recording data of deflection change of the pipeline along with time. Compared with the prior art, the pipeline wet creep performance experimental device provided by the invention has the advantages of low cost, simplicity and convenience in operation, capability of carrying out batch parallel test, and capability of accurately simulating the wet creep performance of a pipeline under a wet environment and a long-term constant load.

Inventors

CHEN JIANZHONG
Wen Surong
LV YONG

Assignees

武汉理工大学

Dates

Publication Date: 20260512
Application Date: 20260209

Claims (10)

1. A pipe wet creep performance test device, comprising: A base unit including a base and a pressure sensor disposed on the base; the water tank is arranged on the pressure sensor, the top of the water tank is opened, and a pipeline is placed in the water tank; a loading unit having a loading end capable of applying a load to the pipe in a vertically downward direction.
2. The pipe wet creep performance test apparatus according to claim 1, wherein the loading unit includes a plurality of support rods, a loading plate and a balancing weight, the plurality of support rods are vertically disposed and disposed around the water tank, lower ends of the support rods are fixedly connected with the base, respectively, the loading plate is located right above the water tank and slidably connected with each support rod, and is capable of sliding in a vertical direction along the support rods, the balancing weight is disposed on the loading plate, and the loading plate is used for applying a load to the pipe.
3. The pipe wet creep performance test apparatus according to claim 2, wherein the loading unit further comprises a pressing block, the lower end of the pressing block is the loading end, the length of the loading end is greater than that of the pipe, the pressing block is located below the loading plate, can extend into the water tank and is in contact with the pipe, and the loading plate applies a load to the pipe through the pressing block.
4. The pipe wet creep performance experiment device according to claim 2, wherein the loading unit further comprises a fixing nut, the supporting rods are provided with external threads, through holes corresponding to the supporting rods one by one are formed in the loading plate, the fixing nut is sleeved on the supporting rods and meshed with the external threads, and the loading plate is placed on the fixing nut.
5. The pipe wet creep performance test apparatus according to claim 1, wherein the water tank is transparent to at least a side of one of the pipe ends.
6. A method for testing the wet creep performance of a pipeline, which is characterized by adopting the device for testing the wet creep performance of the pipeline according to any one of claims 1 to 5, and comprising the following steps: Measuring and calculating initial ring stiffness and experimental load of the pipeline; placing the pipeline in a water tank, injecting water into the water tank until the pipeline is completely submerged, and applying the experimental load to the pipeline through a loading unit; data of deflection of the pipe over time are recorded.
7. The method of claim 6, wherein measuring the initial loop stiffness and the experimental load of the pipe comprises the steps of: Drawing a plurality of reference lines along the diameter of one end of the pipeline, wherein each reference line is uniformly distributed along the circumferential direction of the pipeline, measuring and calculating the wall thickness, the length, the outer diameter and the middle diameter of the pipeline at each reference line respectively, and then calculating the average wall thickness, the average length, the average outer diameter and the average middle diameter of the pipeline; and placing the pipeline in a universal testing machine, gradually increasing the load applied to the pipeline by the universal testing machine according to a preset speed, stopping the universal testing machine until the deflection of the pipeline reaches an experimental preset value, wherein the load applied by the universal testing machine is an initial load, calculating the initial ring stiffness of the pipeline according to the initial load, and calculating the experimental load of the pipeline according to the initial ring stiffness.
8. The method of claim 7, wherein one of the reference lines is selected as an initial reference line, and the initial reference line points in the same direction as the end face of the pipe in which the initial reference line is located when the pipe is placed in the universal tester and the water tank.
9. The method for testing the wet creep performance of a pipeline according to claim 7, wherein the calculation formula of the loading speed v of the universal testing machine is v=0.00035D 2 /e, wherein D is the average middle diameter of the pipeline, and e is the average thickness of the pipeline.
10. The method according to claim 7, wherein the relation between the ring stiffness S and the load F is S= (0.0186+0.025 Δy/D) F/(ΔyL), Δy is the deformation of the pipe, L is the average length of the pipe, and D is the average middle diameter of the pipe.

Description

Pipeline wet creep performance experimental device and experimental method Technical Field The invention relates to the technical field of testing wet creep performance of pipelines, in particular to a device and a method for testing wet creep performance of a pipeline. Background Glass Fiber Reinforced Plastic (GFRP) tubes are widely used in the fields of municipal engineering, petrochemical engineering, ocean engineering and the like with extremely high requirements on durability due to the outstanding advantages of light weight, high strength, excellent corrosion resistance, convenient construction and the like. These pipes need to withstand not only long-term static and dynamic loads during service, but their performance is more susceptible to significant environmental (especially moisture, chemical media). In actual engineering, the pipeline is often buried underground or immersed in water, and is in a continuous wet or dry-wet alternating environment. Moisture can penetrate into the composite material and may cause plasticization, swelling, and even hydrolysis of the resin matrix, and debonding of the fiber/resin interface, resulting in degradation of material properties, particularly long-term creep properties. Therefore, the long-term mechanical behavior of the GFRP tube in a wet environment is accurately estimated and predicted, and is very important for guaranteeing the structural safety and reliability of the GFRP tube in the whole design life. However, there are significant limitations to the current experimental research methods for wet creep performance of such pipelines. The conventional experimental device has the defects in the aspects of simulating a real wetting environment, realizing parallel testing of a plurality of samples, ensuring long-term constant load and the like, and influences the accuracy, reliability and efficiency of experimental data. Therefore, there is an urgent need in the art for a testing scheme capable of overcoming the above-mentioned drawbacks, that is, a testing method and its matching device for testing wet creep performance of a pipeline, which has low cost, simple operation, batch performance, and accurate simulation of wet environment and long-term load. Disclosure of Invention The invention aims to overcome the technical defects, provides a pipeline wet creep performance experimental device and an experimental method, and solves the technical problems that experimental equipment capable of simulating a real wet environment, realizing parallel testing of a plurality of samples and guaranteeing long-term constant load is lacking in the prior art. In order to achieve the technical purpose, the invention adopts the following technical scheme: in a first aspect, the invention provides a pipeline wet creep performance experimental device, which comprises a base unit, a water tank and a loading unit, The base unit comprises a base and a pressure sensor, wherein the pressure sensor is arranged on the base; The water tank is arranged on the pressure sensor, the top of the water tank is opened, and a pipeline is placed in the water tank; The loading unit has a loading end capable of applying a load to the pipe in a vertically downward direction. In some embodiments, the loading unit includes a plurality of support rods, a loading plate and a balancing weight, the plurality of support rods are vertically arranged and are arranged around the water tank, the lower ends of the support rods are fixedly connected with the base respectively, the loading plate is located right above the water tank and is slidably connected with each support rod, the loading plate can slide along the support rods in the vertical direction, the balancing weight is placed on the loading plate, and the loading plate is used for applying load to the pipeline. In some embodiments, the loading unit further includes a pressing block, the lower end of the pressing block is the loading end, the length of the loading end is greater than the length of the pipeline, the pressing block is located below the loading plate, and can extend into the water tank and contact with the pipeline, and the loading plate applies a load to the pipeline through the pressing block. In some embodiments, the loading unit further comprises a fixing nut, the supporting rod is provided with external threads, through holes corresponding to the supporting rods one by one are formed in the loading plate, the fixing nut is sleeved on the supporting rod and is in meshed connection with the external threads, and the loading plate is placed on the fixing nut. In some embodiments, the tank is transparent to at least the side of one of the ends of the pipe. In a second aspect, the invention also provides a pipeline wet creep performance experiment method, which adopts the pipeline wet creep performance experiment device and comprises the following steps: Measuring and calculating initial ring stiffness and experimental load of the pipeli