Low-temperature ice pool test device and method for upward floating icebreaking process of underwater structure

Abstract

The invention provides a low-temperature ice pool test device and method for the upward floating icebreaking process of an underwater structure, and relates to the technical field of ice pool tests, the test method comprises the following steps: step 1, preparing a model ice cover similar to natural sea ice in physical and mechanical properties; 2, installing a test system, and installing the special-shaped structure model on the test system; 3, controlling the vertical lifting unit to drive the special-shaped structure model to float upwards so as to impact the model ice cover; 4, in the floating process of the special-shaped structure model, monitoring and dynamically adjusting the horizontal posture of the special-shaped structure model in real time through the self-compensation structure; and 5, synchronously acquiring mechanical response data of the special-shaped structure model in the icebreaking process and visual image data of ice cover damage. According to the invention, the floating icebreaking process of the special-shaped structure can be truly and accurately simulated, the structure attitude is kept stable in the process, and high-precision mechanical and visual data are synchronously acquired.

Description

Technical Field

[0001] This invention relates to the field of ice-water pool testing technology, specifically to a low-temperature ice-water pool testing device and method for the ice-breaking process of an underwater structure floating upwards. Background Technology

[0002] With global warming and the gradual extension of the navigability of Arctic shipping routes, the geostrategic and resource development value of the polar regions is constantly rising. Against this backdrop, the polar regions are increasingly becoming a strategic focus for various countries in resource development, shipping, and military deployment. Polar scientific expeditions, resource exploration, and military applications all require submersibles to possess reliable icebreaking capabilities, a process involving complex mechanical problems related to the strong coupling interaction between ice and structure. Ice, as a quasi-brittle and heterogeneous material, often exhibits typical evolutionary characteristics of crack initiation, propagation, bifurcation, and eventual fracture when subjected to localized loads on the submersible structure; while the submersible structure needs to maintain its stability and structural strength margin under complex ice loads.

[0003] Current domestic and international research mainly focuses on the influence analysis of sea ice physical parameters, the prediction of structural response under ice loads, and the establishment of numerical simulation models. Simulating the structural buoyancy process using an ice-water tank test device to obtain typical ice failure modes and structural load changes is one effective method. However, current research on crack propagation and evolution mechanisms, spatiotemporal load distribution characteristics, and optimized design methods for icebreaking structures during the buoyancy and icebreaking process of different structures remains insufficient. Addressing the problems of uncontrollable attitude, significant impact on data accuracy due to disturbances, and high difficulty in testing irregular structures in current ice-water tank buoyancy and icebreaking test technologies, there is an urgent need to develop a low-temperature ice-water tank test device and method for the underwater structure buoyancy and icebreaking process. Summary of the Invention

[0004] To address the problems existing in current ice-water pool floating and ice-breaking test technology, such as uncontrollable attitude, significant impact on data accuracy due to disturbances, and high difficulty in testing irregular structures, this invention proposes a low-temperature ice-water pool test device and method for the floating and ice-breaking process of underwater structures.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows:

[0006] This invention proposes a low-temperature ice-water pool test device for the underwater structure's surfacing and ice-breaking process. The device includes a vertical lifting unit and a support arm. The device also includes a self-compensating structure. The vertical lifting unit is connected to the self-compensating structure via the support arm. A non-standard structural model is mounted on the self-compensating structure, which includes a box-shaped frame structure fixedly connected to the support arm. Multiple retractable driving components are installed inside the box-shaped frame structure, and their working ends are connected to a cover plate. An angle sensor is installed at the bottom of the cover plate, and the non-standard structural model is fixedly connected to the cover plate. The vertical lifting unit drives the self-compensating structure and the non-standard structural model to reciprocate vertically, achieving the surfacing and ice-breaking and submerging / resetting of the non-standard structural model.

[0007] Furthermore, the retractable drive component includes a retractable electric cylinder.

[0008] Furthermore, a force measuring unit is provided between the self-compensating structure and the irregular structure model, and the mechanical response data of the irregular structure model during the ice-breaking process is collected synchronously through the force measuring unit.

[0009] Furthermore, the force measuring unit includes several force sensors, which are evenly distributed below the irregular structure model.

[0010] Furthermore, a camera device is installed above the irregular structure model and above the ice layer of the ice water pool to simultaneously collect visual image data of ice cover damage.

[0011] This invention also proposes a testing method for a low-temperature ice-water pool test device based on the underwater structure floating and ice-breaking process, the testing method comprising the following steps: Step 1: Prepare a model ice sheet with physical and mechanical properties similar to natural sea ice; Step 2: Fix the irregular structure model to be tested onto the cover plate; Step 3: Control the vertical lifting unit to drive the support arm to move the irregular structure model upward to impact the model ice cover; Step 4: During the floating process of the irregular structure model, the tilt angle of the cover plate is monitored by the tilt angle sensor, and based on the monitored tilt angle signal, the telescopic drive component is controlled to perform coordinated telescopic actions to dynamically adjust the attitude of the cover plate, so that the irregular structure model maintains the set horizontal attitude. Step 5: Simultaneously collect the mechanical response data of the irregular structure model during the ice-breaking process and the visual image data of ice sheet damage.

[0012] Furthermore, in step one, the preparation of the model ice cap specifically includes: preparing a urea aqueous solution, lowering the water temperature to near freezing point using a cold air unit, then performing atomized spraying to induce ice crystal growth, and controlling the bending strength of the model ice cap by controlling the reheating process.

[0013] Furthermore, in step three, the force sensor is first installed and fixed on the self-compensating structure, and then the irregular structure model is fixed on the force sensor to ensure that the center of gravity of the model structure is consistent with the center of gravity of the base; the connection between the irregular structure model and the force sensor is checked to ensure that the load signal is transmitted accurately; the operating parameters of the servo motor are set, including the floating speed; the initial test data are recorded, including the ice cover thickness, the position of the model structure, and the ambient temperature parameters.

[0014] Furthermore, in step four, the tilt angle of the irregular structure model during the ice-breaking process is dynamically controlled within 0.5 degrees by adjusting the self-compensating structure.

[0015] The beneficial effects of this invention are: 1. This invention, through a self-compensating structure integrating an inclination sensor and multiple independently extendable drive components, can monitor and dynamically adjust the horizontal attitude of the irregular structure model in real time, and stably control its inclination angle within a very small range (within 0.5 degrees). This ensures that the structure model is always in contact with the ice sheet in the preset ideal attitude during the test, greatly improving the accuracy and authenticity of the test.

[0016] 2. This invention integrates the entire process from model ice preparation and experimental device control to data acquisition and analysis, forming a systematic and reliable platform for testing and optimizing the ice-breaking performance of irregular structures. Through this invention, an experimental platform suitable for different ice thicknesses and strengths is constructed to simulate the entire process of irregular structures floating and breaking through ice. This method can realistically and accurately simulate the floating and ice-breaking process of irregular structures, maintaining structural stability during the process and simultaneously acquiring high-precision mechanical and visual data, providing reliable data support for theoretical research and numerical model construction. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the test system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the self-compensation structure in the experimental system of this invention.

[0018] In the diagram: 1-Servo motor; 2-Transmission guide rail; 3-Vertical lifting unit; 4-Support arm; 5-Self-compensating structure; 6-Force sensor; 7-Irregular structure model; 8-Camera equipment; 9-Model ice cover; 10-Tilt sensor; 11-Cover plate; 12-Extendable drive component. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Specific Implementation Method 1: This implementation method proposes a low-temperature ice-water pool test device for the ice-breaking process of underwater structures. The test device is installed in a low-temperature ice-water pool laboratory and is used to test the ice-breaking performance of irregularly shaped structures. For example... Figure 1 and Figure 2 As shown, the testing device includes a vertical lifting unit 3, a support arm 4, and a self-compensating structure 5. The support arm 4 is connected to the lifting end of the vertical lifting unit 3, and the self-compensating structure 5 is connected to the support arm 4. An irregular structure model 7 is set on the self-compensating structure 5. The vertical lifting unit 3 drives the self-compensating structure 5 and the irregular structure model 7 on it to reciprocate in the vertical direction, thereby realizing the upward icebreaking and downward resetting of the irregular structure model 7.

[0021] A force measuring unit is also set between the self-compensating structure 5 and the irregular structure model 7, and a camera device 8 is set above the irregular structure model 7 and above the ice layer of the ice water pool.

[0022] The vertical lifting unit 3 includes a bracket, with a vertical ball screw and linear guide rail arranged along the length (vertical direction) of the bracket. A servo motor 1 is mounted on the upper end of the bracket, and the output end of the servo motor 1 is connected to one end of the ball screw, driving the ball screw to rotate. The nut pair of the ball screw and the slider of the linear guide rail are fixedly connected to a mounting plate, which is fixedly connected to the support arm 4. The lifting speed can be precisely adjusted within the range of 1-300mm / s, with a control accuracy of 0.02mm / s. The transmission guide rail 2 adopts a pre-tightened slider structure to eliminate movement gaps and form a constraint system with high torsional stiffness, avoiding lateral swaying due to off-center loading during upward loading.

[0023] The support arm 4 includes a vertical section and a horizontal section, which are fixedly connected in an L-shape. The vertical section is fixedly connected to the mounting plate of the vertical lifting unit 3, and the horizontal section is connected to the self-compensating structure 5 and the irregular structure model 7.

[0024] The self-compensation structure 5 is as follows Figure 2As shown, the device includes a box-shaped frame structure, which is fixedly connected to the horizontal section of the support arm 4. Several retractable drive components are installed inside the box-shaped frame, and the working ends of these components are connected to a cover plate 11. A tilt sensor 10 is located at the geometric center of the bottom of the cover plate 11. The irregularly shaped structure model 7 is connected to the cover plate 11. A control unit is signal-connected to the tilt sensor 10 and the retractable electric cylinder 12. In this embodiment, the retractable drive component is the retractable electric cylinder 12. When uneven contact between the irregularly shaped structure model 7 and the ice cover causes the cover plate 11 to tilt during the ascent process, the control unit will immediately drive the corresponding retractable electric cylinder 12 to perform extension and retraction compensation based on the signal from the tilt sensor 10, dynamically controlling the horizontal tilt angle of the cover plate 11 within 0.5°, thereby ensuring that the irregularly shaped structure model 7 maintains a horizontal attitude throughout the ice-breaking process.

[0025] The force measuring units are evenly distributed below the irregular structure model 7. They employ a high-precision force sensor 6 with a range of 500 kgf, an accuracy of 0.05% FS, and a sampling frequency of 100 Hz, for real-time measurement of vertical ice-breaking loads.

[0026] The camera device 8 is a high frame rate camera, mounted above the ice surface, used to record the process of crack propagation in the ice sheet.

[0027] Specific Implementation Method Two: This implementation method proposes a low-temperature ice-water pool test method for the ice-breaking process of underwater structures surfacing. The method is implemented using the test device described in Specific Implementation Method One, and includes the following steps: S1. Prepare a model ice sheet 9 with physical and mechanical properties similar to natural sea ice, specifically including: Prepare a urea solution at a ratio of 1.5% and stir it evenly in a water tank.

[0028] The laboratory was then cooled using a cold air unit, gradually bringing the water temperature close to freezing point.

[0029] Once the water temperature approaches freezing point, remove large crystals and small ice fragments from the water. Atomize the urea solution and spray it onto the water surface to form micro-ice crystals, which serve as ice crystal nuclei and induce ice crystals to grow from top to bottom.

[0030] Before the ice thickness reaches the predetermined value, the ice strength index is controlled through the reheating process, the bending strength of the ice is adjusted, and the ice strength is monitored in real time using the cantilever beam method to ensure that the test requirements are met.

[0031] S2. Install the testing device and fix the irregular structure model 7 to be tested on the cover plate 11. S3. Control the vertical lifting unit 3 to drive the support arm 4 to move the irregular structure model 7 upward to impact the model ice cover 9; First, install and fix the force sensor 6 onto the self-compensating structure 5. Then, fix the irregular structure model 7 onto the force sensor 6, ensuring that the center of gravity of the model structure is consistent with the center of gravity of the base. Check the firmness of the connection between the irregular structure model 7 and the force sensor 6 to ensure accurate load signal transmission. Set the operating parameters of the servo motor 1, including the floating speed. Record the initial test data, including parameters such as ice cover thickness, model structure position, and ambient temperature.

[0032] Start servo motor 1 to make the irregular structure model 7 begin to float up and break the ice at the set speed.

[0033] S4. During the floating process of the irregular structure model 7, the tilt angle of the cover plate 11 is monitored by the tilt angle sensor 10, and based on the monitored tilt angle signal, the telescopic drive component 12 is controlled to perform coordinated telescopic action to dynamically adjust the attitude of the cover plate 11, so that the irregular structure model 7 maintains the set horizontal attitude and the tilt angle is dynamically controlled within 0.5 degrees.

[0034] S5. Mechanical response data during the ice-breaking process is simultaneously collected using a force-measuring unit, and visual image data of ice sheet damage is simultaneously collected using camera equipment 8, specifically including: Force sensor 6 records in real time the load changes experienced by the irregular structure model during its ascent, including the initial contact load, peak ice-breaking load, and dynamic changes during continuous ice-breaking. Fixed and mobile high-definition cameras 8 simultaneously record the ice-breaking process, including ice cover deformation, crack propagation paths, and ice failure modes; underwater camera 8 monitors the dynamic changes in the contact area between the irregular structure model and the ice.

[0035] Multi-channel data collected during the experiment were compiled, including load time series and crack propagation images. The load data were comprehensively analyzed to plot the relationship between load and the velocity and tilt angle of the underwater irregular structure model, revealing the correlation between ice-breaking load and the motion parameters of the underwater irregular structure model. Crack propagation images were analyzed to extract the dynamic characteristics of crack generation, propagation, and penetration. The relationship between ice failure modes and the design of the underwater irregular structure model was explored in conjunction with the load data.

[0036] This invention can realistically and accurately simulate the icebreaking process of irregular structures while maintaining structural stability and simultaneously collecting high-precision mechanical and visual data, providing a reliable experimental method for in-depth research on the icebreaking performance of irregular structures.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A low-temperature ice-water pool test device for the underwater structure floating and ice-breaking process, comprising a vertical lifting unit (3) and a support arm (4), characterized in that, The testing device also includes a self-compensating structure (5). The vertical lifting unit (3) is connected to the self-compensating machine structure (5) via a support arm (4). The self-compensating structure (5) is provided with a non-standard structure model (7). The self-compensating structure (5) includes a box frame structure. The box frame structure is fixedly connected to the support arm (4). The box frame structure is provided with multiple telescopic drive components (12). The working ends of the multiple telescopic drive components (12) are connected to a cover plate (11). The bottom of the cover plate (11) is provided with an angle sensor (10). The non-standard structure model (7) is fixedly connected to the cover plate (11). The vertical lifting unit (3) drives the self-compensating machine structure (5) and the non-standard structure model (7) on it to reciprocate in the vertical direction, thereby realizing the floating and icebreaking and diving and resetting of the non-standard structure model (7).

2. The low-temperature ice-water pool test device for the underwater structure buoyancy and ice-breaking process according to claim 1, characterized in that, The retractable drive component includes a retractable electric cylinder.

3. The low-temperature ice-water pool test method for the underwater structure's buoyancy and ice-breaking process according to claim 2, characterized in that, A force measuring unit is provided between the self-compensating structure (5) and the irregular structure model (7), and the mechanical response data of the irregular structure model (7) during the ice-breaking process is collected synchronously through the force measuring unit.

4. The low-temperature ice-water pool test method for the ice-breaking process of an underwater structure buoyancy according to claim 3, characterized in that, The force measuring unit includes several force sensors (6), which are evenly distributed below the irregular structure model (7).

5. The low-temperature ice-water pool test method for the ice-breaking process of an underwater structure buoyancy according to claim 4, characterized in that, A camera device (8) is installed above the irregular structure model (7) and above the ice layer of the ice pool. The camera device (8) synchronously collects visual image data of ice cover damage.

6. A test method for a low-temperature ice-water pool test device for the underwater structure buoyancy and ice-breaking process according to any one of claims 1 to 5, characterized in that, The testing method includes the following steps: Step 1: Prepare a model ice sheet with physical and mechanical properties similar to natural sea ice (9); Step 2: Fix the irregular structure model (7) to be tested onto the cover plate (11); Step 3: Control the vertical lifting unit (3) to drive the support arm (4) to move the irregular structure model (7) upward to impact the model ice cover (9); Step 4: During the floating process of the irregular structure model (7), the tilt angle of the cover plate (11) is monitored by the tilt angle sensor (10), and based on the monitored tilt angle signal, the telescopic drive component (12) is controlled to perform coordinated telescopic actions to dynamically adjust the attitude of the cover plate (11) so that the irregular structure model (7) maintains the set horizontal attitude. Step 5: Simultaneously collect the mechanical response data of the irregular structure model (7) during the ice-breaking process and the visual image data of ice cover destruction.

7. The low-temperature ice-water pool test method for the ice-breaking process of an underwater structure buoyancy according to claim 6, characterized in that, In step one, the preparation of the model ice cover (9) specifically includes: preparing a urea aqueous solution, lowering the water temperature to near freezing point by a cold air unit, spraying atomized water to induce ice crystal growth, and controlling the bending strength of the model ice cover (9) by controlling the reheating process.

8. The low-temperature ice-water pool test method for the ice-breaking process of an underwater structure buoyancy according to claim 7, characterized in that, In step three, the force sensor (6) is first installed and fixed on the self-compensating structure (5), and then the irregular structure model (7) is fixed on the force sensor (6) to ensure that the center of gravity of the model structure is consistent with the center of gravity of the base. Check the connection between the irregular structure model (7) and the force sensor (6) to ensure that the load signal is transmitted accurately; Set the operating parameters of the servo motor (1), including the floating speed; record the initial data of the experiment, including the ice cover thickness, model structure position and ambient temperature parameters.

9. The low-temperature ice-water pool test method for the ice-breaking process of an underwater structure buoyancy according to claim 8, characterized in that, In step four, by adjusting the self-compensating structure (5), the tilt angle of the irregular structure model (7) during the ice-breaking process is dynamically controlled within 0.5 degrees.

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