CN-122016234-A - Method for testing ice breaking total force and ice load space distribution state in floating ice breaking process

CN122016234ACN 122016234 ACN122016234 ACN 122016234ACN-122016234-A

Abstract

The invention relates to a method for testing the spatial distribution state of total ice breaking force and ice load in the process of floating ice breaking, and belongs to the technical field of ice water pool model tests. The method comprises the steps of enabling a model to be located below an ice cover, controlling the model to float at a preset speed to simulate a floating ice breaking process, synchronously measuring total ice load born by the model and local ice load of each sectional model in the floating ice breaking process to obtain a space distribution state of the ice load, and calibrating and correcting the inertia force based on the measured ice load data by an inertia force interference elimination system to obtain a corrected net ice load. When the ice load test is carried out, the invention can effectively eliminate the interference of inertial force in real time and ensure the accuracy of the test result.

Inventors

GAO JINCHENG
YANG DAI
TANG MIN
LIU GUOCANG
ZHU SHIYANG
FU XIN
HUANG YAN
TIAN YUFENG

Assignees

中国船舶集团有限公司第七一九研究所
天津大学

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (9)

1. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the floating ice breaking process is characterized by comprising the following steps of: The method comprises the steps of positioning a model (6) below an ice cover (10), controlling the model (6) to float at a preset speed to simulate a floating ice breaking process, synchronously measuring the total ice load received by the model (6) and the local ice load of each sectional model in the floating ice breaking process to obtain the space distribution state of the ice load, and calibrating and correcting the inertia force of the ice load data obtained by measurement based on an inertia force interference elimination system to obtain the corrected net ice load.
2. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the process of floating ice breaking according to claim 1, wherein a testing device for installing a model (6) is arranged below the ice cover (10), and the testing device comprises: one end of each vertical limb (2) is connected with the output end of the lifting servo device (9), the other end of each vertical limb (2) is connected with one end of each horizontal limb (3), the other end of each horizontal limb (3) is connected with the rigid base (4) through the hinged seat (7), the two sides of each hinged seat (7) are respectively provided with the rigid base (4) which is detachably connected with the horizontal limb (3), the rigid base (4) is supported above the cushion block (8), the test unit (5) is arranged on the rigid base (4), and the model (6) is arranged on the test unit (5).
3. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the upward floating ice breaking process according to claim 2 is characterized in that the model (6) is a submarine segmented model, the model (6) is provided with segments at linear abrupt changes of the model structure, and each segment of the model (6) is correspondingly provided with a group of test units (5).
4. A method for testing the spatial distribution of the total force of breaking ice and the load of ice in the process of floating ice breaking according to claim 2 or 3, wherein the testing unit (5) comprises a load cell and a speed sensor for synchronously measuring the ice load and the motion response of the model.
5. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the process of floating ice breaking according to claim 4, wherein the method comprises the following steps of: s1, preparing a model ice cover (10) in an ice water tank; S2, arranging a testing device provided with a model (6) at a preset position in the ice water tank, so that the testing device is positioned below the model ice cover (10); S3, controlling the model (6) to float upwards at a preset speed through the lifting servo device (9), and simulating a floating ice breaking process; S4, in the process of floating ice breaking, synchronously measuring the total ice load received by the model (6) and the local ice load of each sectional model through the test unit (5) to obtain the space distribution state of the ice load; S5, based on the inertial force interference elimination system, inertial force calibration and correction are carried out on the ice load data obtained through measurement, and the corrected net ice load is obtained.
6. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the floating ice breaking process according to claim 5, wherein the preparation of the model ice cover (10) in the step S1 comprises the following steps: S101, reducing the ambient temperature of the ice water pond to minus 20 ℃ to minus 25 ℃ and keeping uniform; s102, spraying water at 28-30 ℃ to the upper air of the water surface of the ice pool at 19-21 atmospheres by using an industrial spray gun, and carrying out spray seeding; S103, closing refrigeration air supply during spraying seeding, and controlling the water surface wind speed to be lower than 0.1m/S; And S104, continuing cooling after seeding is completed, so that the ice cover grows to a preset thickness.
7. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the floating ice breaking process according to claim 6, wherein in step S5, the inertial force interference elimination system realizes data correction by the following steps: s501, weighing each segment model and each testing device before the test to obtain quality parameters; S502, performing a floating determination test in an ice-free still water environment, and repeating for a plurality of times to obtain motion response and force measurement data of each segment model; S503, calculating equivalent mass, damping coefficient and bias parameter of each segment according to the calibration data; S504, in a formal test, correcting the ice load measured by each segment in real time based on the following formula: Wherein F ice,i (t) is the net ice load of the ith section, F meas,i (t) is the data measured by the ith section load cell, m eff,i is the equivalent mass of the ith section model and consists of the section model mass, the testing device mass and the additional mass, c 1,i is the ith section linear damping coefficient, c 2,i is the ith section secondary damping coefficient, b i is the ith section bias, v i (t) is the ith section vertical speed, and a i (t) is the ith section vertical acceleration.
8. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the upward floating ice breaking process according to claim 7, wherein the measuring range of the testing unit (5) is estimated based on a semi-theoretical semi-empirical formula of the vertical breaking force of the ice layer in the surface contact ice breaking mode, and the formula is as follows: wherein P f is the vertical damage load of the ice layer when the annular crack penetrates, sigma N is the bending strength of the ice layer, h is the thickness of the ice layer, k is a dimensionless constant, R is the damage radius of the ice layer, and L is the characteristic length of the ice layer; Wherein E is the elastic modulus of ice, v is the Poisson's ratio of ice, ρ w is the density of water, g is the gravitational acceleration.
9. The method for testing the spatial distribution state of the total ice breaking force and the ice load in the upward floating ice breaking process according to claim 8, wherein the distance between the edge of the submersible segment model (6) and the free boundary of the ice cover and the pool wall is not smaller than 1 time of the characteristic length L of the ice layer when the submersible segment model is arranged.

Description

Method for testing ice breaking total force and ice load space distribution state in floating ice breaking process Technical Field The invention relates to a method for testing an upward floating ice breaking state, and belongs to the technical field of ice water pool model tests. Background Global warming causes progressive ablation of polar sea ice, driving an increase in polar scientific, commercial and resource development activities. In this context, the underwater vehicle may need to perform an ascent icebreaking task during polar operations due to real-time communication or emergency needs. Unlike conventional ship ice breaking, the submerged submersible vessel floating ice breaking involves a breaking and breaking process of the ice cap under vertical load. In the process, the spatial distribution state of ice load on the structure is critical to the structural strength and control design of the submersible. However, the process involves complex multi-physical field coupling and changeable physical and mechanical characteristics of sea ice materials, and no deep and effective research and testing method system is established in the academy of China and abroad and engineering. At present, some scholars develop exploratory researches on the problem through a numerical simulation method, and the methods such as a finite element method, a discrete element method, a smooth particle method and near field dynamics are introduced into the application of the field of ice mechanics. The breathing-up 2022 establishes an underwater vehicle-ice-water coupling model based on an SPH-FEM algorithm, and quantifies the influence of factors such as ice thickness, floating speed and the like on the load space distribution gradient. Wang et al 2021 used LS-DYNA software to simulate the vertical icebreaking and water yielding process of underwater vehicles and accounted for the nonlinear interactions of structure-ice-water. Yue et al 2021 determine main control parameters in the floating ice breaking process of the structure through dimension analysis, and further research the dynamic characteristics of ice load at different initial speeds. Ye et al 2018 establishes a pneumatic mathematical model to simulate the structure float ice breaking process and analyze the timing characteristics of ice loads. She Liyu et al 2018 simulate the contact process of the underwater vehicle and the ice cover by adopting a near field dynamics method, and trace the damage form and load distribution of the ice cover through a contact detection algorithm. Liu Junjie and 2015 simplify the floating ice breaking process of the structure into a multi-body impact process, so that the coupling effect between impact forces is analyzed. In the field of model test research, students focus on collision tests of ice with typical local structures. Vertical concentrated loads are applied to fresh water ice layers on site at 2024, and the damage process of the ice layers is recorded through a displacement sensor and a high-speed camera. Lee et al 2014 laid a plurality of strain measurement points on the inner side of the hull planking, and recorded structural deformation in the loading process. Kim et al 2014 observe the deformation of the plate frame structure and the spatial distribution of ice load by adopting an ice sample free falling impact mode. Choi et al 2012 simulated the process of steel plate striking ice cubes in the laboratory, tested impact force and ice breaking pattern under different conditions by controlling the steel plate inclination angle and striking speed. Gagnon2004 used model ice to simulate the collision process of floating ice with the hull, and measured the contact pressure time course of the ship model surface. In summary, aiming at the problem of floating ice breaking of the underwater vehicle, the existing research work mainly comprises two means of numerical simulation and local structure test. With the continuous development of finite element, discrete element, near field dynamics and other methods, the numerical simulation method can more completely reproduce the whole process of the contact and damage of the submersible vehicle and the ice cover, but the calculation result still needs to be verified by a physical model test or a field test due to the complexity of the constitutive relation of the ice material. The physical model test method is limited by geometric scale ratio and laboratory conditions, and can only test the local structure of the submersible vehicle, and can not simulate the floating ice breaking process of the complete submersible vehicle. Because each part of the structure of the submersible has obvious coupling effect in the process of breaking ice, the ice breaking test result aiming at the local structure independently has certain deviation with the floating ice breaking result of the corresponding part of the complete submersible structure. The invention discloses a test method for a space distrib