A test method for simulating the influence of dynamic load on bearing characteristics of a wind power foundation

Abstract

This invention discloses a test method for simulating the influence of dynamic loads on the bearing characteristics of wind turbine foundations, as well as an experimental device for cooperating with the test method. The device includes a base, a model box, a dynamic load response mechanism, a main hammer, and a data acquisition and processing system. The base includes casters, a pedal, a connecting rod, and a water outlet. The model box includes a drop hammer hole, an inclined groove, a sealing ring, and a transparent rubber sheet. The dynamic load response mechanism includes a U-shaped hollow groove, a fixed pulley, a buffer groove, a telescopic rod, and a telescopic hydraulic support. The data acquisition and processing system includes a computer and a displacement / strain sensor. After the main hammer strikes the soil in the model box, it simulates marine seismic loads and tests the deformation of the soil and the bearing characteristics of the foundation after being disturbed by dynamic loads.

Description

Technical Field

[0001] This invention relates to the research of a test device for the bearing capacity of offshore wind power foundations, and in particular to a test method for simulating the influence of dynamic loads on the bearing characteristics of wind power foundations. Background Technology

[0002] With the implementation of the "Maritime Power" strategy for telescopic hydraulic props, my country's marine engineering industry has entered a period of rapid development in recent years, especially the offshore wind power industry, which has become a fundamental choice for energy transformation. However, as wind power technology develops towards deeper waters, marine engineering foundations face more complex load environments (such as seismic loads), and their load-bearing characteristics have a significant impact on the safety and durability of wind power foundation structures.

[0003] Therefore, to improve the safety of wind turbine foundations after the impact of seismic loads, it is necessary to clarify the impact of seismic loads on the bearing characteristics of wind turbine foundations. However, seismic loads are accidental loads, occurring within a short period and causing significant damage; more precise testing of the various performance parameters of wind turbine foundations affected by seismic loads requires highly realistic simulations of disaster conditions. Existing experimental facilities mainly focus on studying offshore wind, current, and wave loads, and research on offshore seismic loads remains limited.

[0004] Existing research reports on related technologies mainly include:

[0005] Chinese Patent Publication No. CN113790869A, published on December 14, 2021, discloses a dynamic load measurement device for a floating offshore wind power model. This device simulates the roll / pitch motion of the floating offshore wind power model by designing a rotation system under the combined action of wind, waves and currents. However, this device mainly considers the foundation structure and focuses on the dynamic load study under the action of wind, waves and currents, so it cannot simulate seismic loads.

[0006] Chinese Patent Publication No. CN103185670B, published on September 30, 2015, discloses an impact load monitoring system and method for wind turbines used in wind power generation. The system mainly studies the rotation of the blades under wind load, which causes the main bearing to tilt. It monitors the amplitude change of the main shaft through an acceleration sensor. However, the system cannot actively apply dynamic / impact loads, the study focuses on onshore wind power, and it does not consider the changes in the wind power generation structure after the foundation is subjected to impact loads.

[0007] Chinese Patent Publication No. CN106872289B, published on June 4, 2019, discloses a sand impact load test device and its test method. The device uses a hammer to vertically impact the soil. However, the sample box size is small in the experiment, and the compaction density of the sand increases after the vertical impact force is generated, which limits the study of actual geological conditions. Summary of the Invention

[0008] This invention aims to provide a test method for simulating the impact of dynamic loads on the bearing characteristics of wind power foundations, and to solve the problem of testing relevant performance parameters of the impact of seismic loads on wind power foundations in marine environments. It features accurate and reliable experimental data, a complete system, and convenient operation.

[0009] Therefore, the technical solution adopted in this invention is as follows:

[0010] A test method for simulating the impact of dynamic loads on the bearing characteristics of wind turbine foundations, comprising the following steps:

[0011] A. Soil of a certain height was laid inside the model box according to the experimental requirements to simulate the natural marine environment;

[0012] B will drive the wind power generation foundation model into the soil through a sinking process;

[0013] C places displacement / strain sensors on the basic model;

[0014] D places the dynamic load response mechanism above the model box;

[0015] E. Select the required weights for the experiment, simulate dynamic load, use the gravity method to hit the soil in the model box, test the experimental data, and observe the deformation of the soil and the soil around the wind power generation foundation.

[0016] If you need to simulate multiple dynamic loads or loads from different directions, you can repeat the operation.

[0017] A test method for simulating the influence of dynamic load on the bearing characteristics of wind power foundations, characterized in that: the experimental device for the test method for simulating the influence of dynamic load on the bearing characteristics of wind power foundations includes a base, a model box, a dynamic load response mechanism, a main hammer body, and a data acquisition and processing system. The base and the model box form a model box body. The base includes casters, pedals, connecting rods, and a water outlet. The model box includes a drop hammer hole, an inclined groove, a sealing ring, and a transparent rubber sheet. The model box is placed on top of the base, and the two are fixedly connected.

[0018] The dynamic load response mechanism includes a U-shaped perforated groove, fixed pulleys, a buffer groove, a telescopic rod, and a telescopic hydraulic support. The upper surface of the dynamic load response mechanism features six identical quincunx-shaped structures, with U-shaped perforated grooves between the petals. The fixed pulleys are located at the center of the dynamic load response mechanism, with six evenly arranged at 60° angles, and contact the buffer groove below. The telescopic rod automatically extends and is fixedly connected to the loading system to ensure that the main hammer's descent path does not deviate. The main hammer includes a steel wire rope and a weight. The main hammer and the telescopic rod are at the same horizontal level. The steel wire rope is connected to the fixed pulleys and the weight. Under gravity, the main hammer falls along the telescopic rod down the U-shaped perforated groove into the hammer drop hole. The telescopic hydraulic support is located below the dynamic load response mechanism.

[0019] The data acquisition and processing system includes a computer and displacement / strain sensors. The displacement / strain sensors are positioned at the test site of the wind turbine model foundation and electrically connected to the computer. After the main hammer strikes the soil in the model box, the resulting instantaneous vibration wave is transmitted to the wind turbine foundation. The displacement / strain sensors receive the signal, and the computer performs post-processing to obtain characterization parameters of the soil deformation and foundation bearing capacity after disturbance. Further preferably, the casters are driven by a pedal-driven connecting rod, causing the casters to rotate inwards towards the base, ensuring that the model box structure maintains overall contact with the ground during the experiment and improving the stability of the model box.

[0020] A further preferred embodiment is that the drop hammer holes are evenly arranged, with 6 structural holes provided, to achieve the experimental effect of applying dynamic loads in different orientations.

[0021] A further preferred embodiment is that the transparent rubber sheet is arranged on the inner side wall of the box and is tightly connected to the wall surface through the outer sealing ring to ensure that the soil inside the model box does not flow out.

[0022] More preferably, the buffer groove is arranged at an angle, and a rubber sheet is arranged at its lower end to reduce the pulling force on the wire rope generated during the application of dynamic load, thereby achieving a buffering effect.

[0023] More preferably, the weights are selected according to the experimental requirements, and the dynamic load is applied to the soil by a horizontal-vertical drop method during the experiment.

[0024] A further preferred embodiment is that the top of the telescopic hydraulic support is fixedly connected to the bottom of the dynamic load loading panel, and the height of the hydraulic support is adjusted according to the specific dynamic load requirements during the experiment.

[0025] More preferably, the base and the model box are made of stainless steel and plexiglass, respectively.

[0026] The beneficial effects of this invention are that the device for simulating the influence of dynamic loads on the bearing characteristics of wind power foundations is compact and reasonable in structure and relatively simple to operate. The dynamic load response mechanism can simulate seismic (dynamic) loads in the marine environment. It can conduct research on the safety and stability of wind power foundations through different types of loads and different orientation loading designs, and reveal the mechanism of dynamic loads on wind power foundations. Attached Figure Description

[0027] Figure 1 Schematic diagram of the box structure of the model of this invention

[0028] Figure 2 The dynamic load response mechanism of this invention

[0029] Figure 3 Schematic diagram of the overall working structure of the present invention

[0030] Figure 4 Schematic diagram of the internal structure of the drop hammer hole

[0031] Figure 5 Top view of dynamic load response mechanism

[0032] Figure 6 Telescopic hydraulic prop

[0033] Figure 7 Partial schematic diagram of the telescopic pole structure

[0034] The components include: 1. Base; 1a. Casters; 1b. Pedal; 1c. Connecting rod; 1d. Water outlet; 2. Model box; 2a. Drop hammer hole; 2b. Inclined groove; 2c. Sealing ring; 2d. Transparent rubber sheet; 3. Dynamic load response mechanism; 3a. U-shaped hollow groove; 3b. Fixed pulley; 3c. Buffer groove; 3d. Telescopic rod; 3e. Telescopic hydraulic support; 4. Main hammer body; 4a. Steel wire rope; 4b. Weights; 5. Data acquisition and processing system; 5a. Computer; 5b. Displacement / strain sensor Detailed Implementation

[0035] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0036] like Figure 1 — Figure 7 As shown, an experimental device for testing a method to simulate the influence of dynamic load on the bearing characteristics of wind power foundations is presented. It mainly consists of a base (1), a model box (2), a dynamic load response mechanism (3), a main hammer (4), and a data acquisition and processing system (5).

[0037] The base (1) is located below the model box (2). The caster (1a) is fixed to the connecting rod (1c). The pedal (1b) is placed at the middle of the lower end of the base (1) and is fixedly connected to the connecting rod (1c). When the model box moves to the experimental site, the caster can be driven to rotate into the base telescopic hydraulic support (3e) through the pedal (1b) to ensure that the model box structure is in overall contact with the ground during the experimental process, thereby improving the stability of the model box.

[0038] The drop hammer holes (2a) in the model box (2) are evenly arranged at a distance of 60° along the box wall; the transparent rubber sheet (2d) is arranged on the inner side wall of the box and is tightly connected to the wall through the outer sealing ring (2c), which can ensure that the soil inside the model box (2) does not flow out.

[0039] The upper surface of the dynamic load response mechanism (3) is provided with a plum blossom-shaped structure, which is divided into 6 identical parts. There is a U-shaped hollow groove (3a) between the two petals. The lower telescopic hydraulic support (3e) serves as the support structure, and its height can be adjusted according to requirements in the experiment. The entire dynamic load application process mainly involves:

[0040] First, fix the dynamic load response mechanism (3) to a specific position in the model box (2), that is, the main hammer body (4) and the drop hammer hole (2a) are in a one-to-one correspondence.

[0041] Then, the telescopic rod (3d) is stretched to a certain position to ensure that the main hammer (4) and the telescopic rod (3d) are at the same horizontal position and are placed in the middle of the two telescopic rods (3d) to ensure that the falling path of the main hammer (4) does not deviate. During this process, the weight (4b) can be selected according to the experimental requirements. After the steel wire rope (4a) in the main hammer (4) is connected to the fixed pulley (3b), the pulley is fixed. The buckle is set to prevent rotation during the experiment. The steel wire rope (4a) is placed in the rubber sheet of the buffer groove (3c) to reduce the pull of the steel wire rope (4a) by the transient force generated during the application of dynamic load, so as to achieve the buffering effect.

[0042] Finally, a displacement / strain sensor (5b) is placed at the test site of the wind power model foundation and connected to the computer (5a) to keep the signal smooth. The main hammer (4) is released to strike the soil in the model box (2). The instantaneous vibration wave generated after the strike is transmitted to the wind power generation foundation. The displacement / strain sensor (5b) receives the signal and the computer (5a) processes it to obtain the deformation of the soil after the foundation is disturbed and the characterization parameters of the foundation bearing characteristics.

[0043] To further illustrate the beneficial effects and usage of a test method for simulating the impact of dynamic loads on the bearing characteristics of wind turbine foundations, specific instructions are provided for the operation of the aforementioned device, making it clearer for operators, as follows:

[0044] A. Soil of a certain height was laid inside the model box according to the experimental requirements to simulate the natural marine environment;

[0045] B will drive the wind power generation foundation model into the soil through a sinking process;

[0046] C places displacement / strain sensors on the basic model;

[0047] D places the dynamic load response mechanism above the model box;

[0048] E. Select the required weights for the experiment, simulate dynamic load, use the gravity method to hit the soil in the model box, test the experimental data, and observe the deformation of the soil and the soil around the wind power generation foundation.

[0049] If you need to simulate multiple dynamic loads or loads from different directions, you can repeat the operation.

Claims

1. A test method for simulating the influence of dynamic load on the bearing characteristics of wind power foundation, comprising the following steps: A. A certain height of soil is laid in the model box according to the experimental requirements to simulate the natural environment of the ocean; B. The wind power foundation model is sunk into the soil; C. Displacement / strain sensors are arranged on the foundation model; D. A dynamic load response mechanism is arranged above the model box; E. The experimental weight is selected to simulate the dynamic load, the gravity method is used to hit the soil in the model box, the experimental data is tested, and the deformation of the soil and the surrounding soil of the wind power foundation is observed; F. If multiple dynamic loads or loads in different directions need to be simulated, the operation can be repeated. characterized in that An experimental device for a test method for simulating the influence of dynamic load on the bearing characteristics of wind power foundation, comprising a base (1), a model box (2), a dynamic load response mechanism (3), a main hammer body (4) and a data acquisition and processing system (5), wherein the base (1) and the model box (2) form a model box body, the base (1) comprises casters (1a), a pedal (1b), a connecting rod (1c) and a water outlet (1d), the model box (2) comprises a drop hammer hole (2a), a chute (2b), a sealing ring (2c), a transparent rubber sheet (2d), the model box (2) is arranged above the base (1), and the two are fixedly connected; The dynamic load response mechanism (3) comprises a U-shaped hollow groove (3a), a fixed pulley (3b), a buffer groove (3c), an extension rod (3d) and a telescopic hydraulic prop (3e); the upper surface of the dynamic load response mechanism (3) is provided with six identical plum blossom structures, and a U-shaped hollow groove (3a) exists between two petals; the fixed pulley (3b) is located at the center of the dynamic load response mechanism (3) and is uniformly arranged in six parts at an angle of 60°, and is in contact with the buffer groove (3c) below; the extension rod (3d) is automatically elongated, is fixedly connected with the loading system, and ensures that the falling path of the main hammer body (4) does not deviate; the main hammer body (4) comprises a steel wire rope (4a) and a weight (4b), the main hammer body (4) is located at the same horizontal position between the extension rod (3d), the steel wire rope (4a) is connected with the fixed pulley (3b) and the weight (4b), and under the action of gravity, the main hammer body (4) falls along the extension rod (3d) and enters the drop hammer hole (2a) along the U-shaped hollow groove (3a); the telescopic hydraulic prop (3e) is located below the dynamic load response mechanism (3); The data acquisition and processing system (5) comprises a computer (5a) and a displacement / strain sensor (5b), the displacement / strain sensor (5b) is arranged at the test position of the wind power model foundation and is electrically connected with the computer (5a), after the main hammer body (4) hits the soil in the model box (2), the instantaneous vibration wave generated is transmitted to the wind power foundation, the signal is received by the displacement / strain sensor (5b), and the deformation of the soil after the foundation is disturbed and the characteristic parameters of the foundation bearing characteristics are obtained after the computer (5a) post-processing.

2. The method for testing the influence of dynamic load simulation on the bearing characteristics of a wind power foundation according to claim 1, characterized in that: The caster (1a) is driven by the pedal (1b) to connect the link (1c) to rotate the caster to the inside of the base (1), ensuring that the model box structure is in contact with the ground during the experiment, and improving the stability of the model box.

3. The method of claim 1, wherein the method comprises: The drop hammer holes (2a) are evenly arranged, and six structure holes are provided to realize the experimental effect of different direction dynamic load application.

4. The method of claim 1, wherein the method comprises: The transparent rubber sheet (2d) is arranged on the inner side wall of the box, and is tightly connected with the wall surface through the outer sealing ring (2c), so that the soil in the model box (2) does not flow outwards.

5. The method of claim 1, wherein the method comprises: The buffer groove (3c) is arranged obliquely, and a rubber sheet is arranged at the lower port to reduce the pulling of the transient force generated during the dynamic load application process on the steel wire rope (4a), achieving the effect of buffering.

6. The method of claim 1, wherein the method comprises: The weight (4b) is selected according to the experimental requirements, and the horizontal and vertical falling method is used to apply dynamic load to the soil during the experiment.

7. The method of claim 1, wherein the method comprises: The top end of the telescopic hydraulic prop (3e) is fixedly connected with the bottom of the dynamic load loading panel, and the height of the hydraulic prop is adjusted according to the specific dynamic load requirements during the experiment.

8. The method of claim 1, wherein the method comprises: The base (1) and the model box (2) are respectively made of stainless steel and organic glass.

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