Method for obtaining counterweight for lifting test in land-based test of large sail

Abstract

The present invention discloses a method for obtaining a counterweight for a lifting test in a land-based test of a large sail, which includes the following steps: first, the following parameters are confirmed through design and actual conditions: weight load, inertia load, wind load, and then the horizontal load, vertical load, and bending moment are determined. Secondly, for the structural safety of the sail itself, the horizontal load, vertical load, and bending moment formed by the side pull load cannot exceed the horizontal load, vertical load, and bending moment during normal operation, and the limiting conditions are determined; and the friction generated by the pulley or shaft of the tooling when the mast is raised or lowered needs to be considered. The present invention simulates the working conditions involved in the operation of the sail in a real ship on land, confirms the limit load under each working condition, determines the position of applying the tension in the side pull test for the mechanism setting of the sail mast, and finally forms a counterweight acquisition method according to the boundary conditions, limiting conditions, and scale of the tooling of each working condition, thereby ensuring the smooth implementation of the side pull test.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and more particularly to a land-based test of a large sail. Background Art

[0002] With the promulgation and implementation of new low-carbon emission reduction regulations around the world, the global shipping and shipbuilding industries are moving towards greening. Marine sailing devices use wind energy, a clean energy source, as a driving force, setting off a new wave of revolution internationally. DSIC took the lead in conducting the world's first technical research on wing-shaped wind-powered ocean-going cargo ships, breaking through a series of key technologies, including the formulation of lifting test weights in land-based tests.

[0003] Due to the complex marine environment, when sails are in use, they are subjected to both wind loads and inertial loads caused by the ship. Therefore, the main supporting structure must not fail under the action of these loads to ensure the safety of personnel and ships.

[0004] The mechanical system of a sail consists of a rotating base, a mast and a sail. Since the mast is connected to the rotating base by bolts and the sail is suspended on the mast, the lifting capacity of the sail is mainly determined by the lifting capacity of the mast. In actual use, the mast of a sail needs to overcome weight load, inertia load, wind load and friction load to achieve lifting and lowering. In the side-pull test of the land-based test, the above loads are mainly simulated by side-pull force to examine whether the mast can be smoothly lifted and lowered under the simulated load.

[0005] In the process of simulating the above loads, the weight load and vertical inertia load are realized through the vertical component of the side pull load; the friction force formed by lateral forces such as lateral inertia load and wind load is also realized through the horizontal component of the side pull load; at the same time, the load limit of each mechanical component itself, the mechanical properties of the test tooling itself and the friction between the components must be considered. Summary of the invention

[0006] In order to verify the main structural strength of the sail and the design capability of the lifting system, the present invention takes inertial load, wind load and sail operating conditions as design inputs, simulates the loads that the sail is subjected to in a complex marine environment on land, and loads it with tooling and counterweights to prove the bearing capacity of the mechanical structure and the lifting capacity of the lifting system. A method for obtaining counterweights for the lifting test in the land-based test of the sail is proposed.

[0007] In order to achieve the above object, the present invention provides a method for obtaining a counterweight for a lifting test in a land-based test of a large sail, comprising the following steps:

[0008] S1. Confirm the following parameters through design and actual situation:

[0009] Weight load: including the weight of each mast section, mechanical components and sail surface above the side pull point, recorded as G 1;

[0010] Inertia load: including vertical forces of masts, mechanical components and sails above the side pull point G 2. Lateral forces on masts, mechanical components and sails above each side pull point T 1. Bending moment value at the overlap of each mast section M 1 and friction f 1;

[0011] Wind load: The lateral force on the sail caused by the wind load T 2, and the bending moment value caused by the lateral force M 2 and friction f 2;

[0012] Horizontal load: T 1+ T 2;

[0013] Vertical load: F v + f ,in F v is the weight of each sail component and the vertical force caused by the vertical inertia load on each component. F v = G 1+ G 2; f is the friction force generated by the relative motion of the mast. If the sliding friction coefficient is l , f=f 1+ f 2= λT 1+ λT 2;

[0014] Bending moment: M , is the bending moment caused by the horizontal inertia load and the bending moment caused by the lateral force of the wind, M = M 1+ M 2;

[0015] S2. Determine the load state simulated by the side pull test;

[0016] The vertical distance between the side pull point and the tooling point is h 1. The lowest side pull point is N. At this time, the angle between the side pull wire rope A and the horizontal is i , the distance between the center of the sail and the tooling pulley D is L ;

[0017] The vertical distance between the side pull point and the tooling point is h2. The tooling point is M. At this time, the angle between the side pull wire rope A and the horizontal is i , the distance between the center of the sail and the tooling pulley D is L ;

[0018] F 1 is the weight of the object, which forms a pulling force after passing through the wire rope and the fixed pulley F 2 acts on the mast, then F The horizontal component of force 2 is F 2• cosθ , the vertical component is F 2• sinth The bending moment at the root is F 2• Z • cosθ ;

[0019] S3, decomposing the side-pull process and obtaining the counterweight;

[0020] When the sail is raised, the first process is recorded as P 1, the lowest side pull point height runs to the tooling point height; the second process is recorded as P 2; from the height of the tooling point to the maximum lifting height of the sail; when the sail is lowered, the third process is recorded as P 3, the sail runs from the maximum lifting height to the height of the tooling point; the fourth process is recorded as P 4. The height of the tooling point runs to the lowest side pull point height;

[0021] In process P1, the counterweight is subject to the following constraints on the horizontal component of force:

[0022]

[0023] m is the rolling friction coefficient of the load clamped in the pulley used;

[0024] The counterweight is subject to the constraints of the vertical force in process P1:

[0025]

[0026] The counterweight is subject to the constraints of the total bending moment in process P1:

[0027]

[0028] For the P1 process, Z is the height of the mast from the lowest side-pull point after it is raised;

[0029] In process P2, the counterweight is subject to the following constraints on the horizontal component of force:

[0030]

[0031] The counterweight is subject to the constraints of the vertical force in process P2:

[0032]

[0033] The counterweight is subject to the constraints of the total bending moment in process P2:

[0034]

[0035] For the P2 process, Z is the height of the mast from the tooling point after it is raised;

[0036] The minimum value among the results calculated by equations (4)(5)(6)(9)(10)(11) is taken as F 1, which is the side pull load under the lifting condition; if the lifting process only satisfies P2, that is, the height of the side pull point is always higher than the tooling height, then the results calculated by equations (9), (10), and (11) are taken as the minimum value of these results. F 1;

[0037] In process P3, the counterweight is subject to the following constraints on the horizontal component of force:

[0038]

[0039] The counterweight is subject to the constraints of the vertical force in process P3:

[0040]

[0041] The counterweight is subject to the constraints of the total bending moment in process P3:

[0042]

[0043] For the P3 process, Z is the height of the mast from the tooling point after it is lowered;

[0044] In process P4, the counterweight is subject to the following constraints on the horizontal component of force:

[0045]

[0046] The counterweight is subject to the constraints of the vertical force in process P4:

[0047]

[0048] The counterweight is subject to the constraints of the total bending moment in process P4:

[0049]

[0050] For the P4 process, Z is the height of the mast from the lowest side-pull point after it is lowered;

[0051] The minimum value of the results calculated by equations (14)(15)(16)(19)(20)(21) is taken as F1, which is the side pull load under the descent condition. If the descent process only satisfies P3, that is, the height of the side pull point is always higher than the tooling height, then the minimum value of the results calculated by equations (14)(15)(16) is taken as F1.

[0052] Finally, the load on the sail in the side-pull test was determined.

[0053] In a preferred manner, the inertia load of step S1 includes vertical inertia load and lateral inertia load. The vertical force G2 of each mast section, mechanical component, and sail surface above the side pull point can be obtained by the maximum vertical acceleration aV of the ship where the sail is located, according to aV and the weight of the component; the lateral force T1 of each component can be obtained by the maximum lateral acceleration aL of the ship where the sail is located, and the weight of the component.

[0054] In a preferred manner, the wind load of step S1 and the cross-sectional airfoil of the sail are used to obtain the total force on the sail surface through numerical calculation or wind tunnel test, and then the lateral force T2 caused by the wind load and the bending moment value M2 and friction force f2 caused by the lateral force are obtained according to the calculated area ratio of the sail surface.

[0055] In a preferred manner, in step S3, if the height of the side pull point is higher than the height of the tooling, when the sail is raised, only the P2 process is considered, and when the sail is lowered, only the P3 process is considered. After step S3, according to the control method of the sail, restriction conditions are added to simulate actual working conditions.

[0056] The present invention simulates the working conditions of the sail in the actual ship operation on land, confirms the limit load under each working condition, determines the position of applying the tension in the side pull test for the mechanism setting of the sail mast, and finally forms a counterweight acquisition method according to the boundary conditions, restriction conditions and scale of the tooling of each working condition, thereby ensuring the smooth implementation of the side pull test. Specifically, it has the following effects

[0057] 1. The load types are given, which can be used to complete the input of load calculation and provide guarantee for the accuracy of calculation.

[0058] 2. According to the actual working conditions and the structural bearing capacity, the boundary conditions for the calculation of the side pull load are given to ensure the safety of the land-based test and the sail.

[0059] 3. The load coefficient considering friction is given and can be quickly selected according to the lifting process.

[0060] 4. The lifting process is refined to quickly determine the state of the mast lifting and lowering, and the side pull load is calculated according to the given formula. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of the position relationship when the side pulling point is lower than the tooling point.

[0062] Figure 2 It is a schematic diagram of the position relationship when the side pulling point is higher than the tooling point. DETAILED DESCRIPTION

[0063] First, the land-based test conditions of the sail propulsion system are described. The lifting and lowering ability of the sail needs to be examined in two conditions: one is that the sail is raised from the lowest point to the highest point, and the other is that it is lowered from the highest point to the lowest point. During the test, since the first section of the mast does not move, the wire rope is connected to the top of each section of the mast except the first section, and the mast is pulled sideways through the tooling weight to achieve the lifting and lowering action of the mast.

[0064] During normal operation, the sail needs to withstand horizontal loads, vertical loads and bending moments. Among them, the horizontal load includes the horizontal component of the wind load and the horizontal inertia load caused by the movement of the ship; the vertical load includes the weight of the sail components themselves, the vertical inertia load caused by the movement of the ship, and the friction caused by the mast due to the horizontal load; the bending moment includes the bending moment caused by the horizontal inertia load and the bending moment caused by the lateral force of the wind. The lifting test in the land-based test only simulates these three loads through the side pull load. Therefore, for the structural safety of the sail itself, the horizontal load, vertical load and bending moment formed by the side pull load cannot exceed the horizontal load, vertical load and bending moment during normal operation.

[0065] 1) Loads on the sail under normal operation

[0066] Weight load: Due to the different side pull points, the weight to be considered is also different. The weight load includes the weight of each section of the mast, mechanical components and sail above the side pull point, recorded as G 1.

[0067] Inertia load: Inertia load is generated by the movement of the ship, including vertical inertia load and lateral inertia load. According to the ship design specifications, the maximum vertical acceleration of the ship where the sail is located can be calculated. a V and the maximum lateral acceleration a L , then according to a V As well as the weight of the components, the vertical forces of the mast, mechanical components, and sails above the side pull point can be obtained. G 2. According to a L And the weight of the components, the lateral force of each component can be obtained T 1. Bending moment value at the overlap of each mast sectionM 1 and friction f 1.

[0068] Wind load: The wind load on the sail is related to the cross-sectional airfoil of the sail. The total force on the sail surface can be obtained through numerical calculation or wind tunnel test, and then the lateral force caused by the wind load can be obtained according to the calculated area ratio of the sail surface. T 2, and the bending moment value caused by the lateral force M 2 and friction f 2.

[0069] Then according to the previous discussion, the vertical load, horizontal load and bending moment when the sail is in normal operation can be obtained as shown below.

[0070] Horizontal load: T 1+ T 2

[0071] Vertical load: F v + f ,in F v is the weight of each sail component and the vertical force caused by the vertical inertia load on each component. F v = G 1+ G 2; f is the friction force generated by the relative motion of the mast. If the sliding friction coefficient is l , f=f 1+ f 2= λT 1+ λT 2.

[0072] Bending moment: M , is the bending moment caused by the horizontal inertia load and the bending moment caused by the lateral force of the wind, M = M 1+ M 2.

[0073] 2) Load simulated by the side pull test

[0074] like Figure 1 As shown, the vertical distance between the side pull point and the tooling point is h 1. At this time, the angle between the side-pull wire rope A and the horizontal is i , the distance between the center of the sail and the tooling pulley D is L Similarly, Figure 2 The vertical distance of the side pull point above the tooling point is shown as h 2. At this time, the angle between the side-pull wire rope A and the horizontal is i , the distance between the center of the sail and the tooling pulley D is L .regardless Figure 1 or Figure 2 , F 1 is the weight of the object, which forms a pulling force after passing through the wire rope and the fixed pulley F 2 acts on the mast, then F The horizontal component of force 2 is F 2• cosθ , the vertical component is F 2• sinth The bending moment at the root is F 2• Z • cosθ The simulated horizontal force component, vertical force component and bending moment should be smaller than the horizontal load, vertical load and bending moment under normal operating conditions, respectively.

[0075] Z is a variable. For example, in process P1, the mast moves up from the lowest point of the side pull to the tooling point, and Z is the height of the mast from the lowest side pull point after it is raised. This variable is set here because it is impossible to determine whether this formula is a monotonically increasing or monotonically decreasing function. Taking process P1 as an example, when calculating, the range of Z is 0 to h1, then Z should be assigned at least two values ​​(0 or h1) within the range of 0 to h1, and then the minimum value of the two calculation results is taken.

[0076] Similarly, in process P2, the mast moves upward from the side-pull tooling point to the maximum lifting height of the mast, and Z is the height of the mast from the tooling point after it is raised. That is, when calculating, the variation range of Z is from 0 to h2, so Z should be assigned at least two values ​​(0 or h2) within the range of 0 to h2, and then the minimum value of the two calculation results is taken.

[0077] Processes P3 and P4 are the inverse processes of P2 and P1 respectively, that is, the meaning of Z in process P3 is the same as that in process P2, and the meaning of Z in process P4 is the same as that in process P1.

[0078] 3) Boundary conditions:

[0079] For the structural safety of the sail itself, the horizontal load, vertical load and bending moment caused by the side pull load cannot exceed the horizontal load, vertical load and bending moment during normal operation.

[0080] ① Take horizontal load as the limit condition;

[0081] ② Take vertical load as the limit condition;

[0082] ③ Taking bending moment as the limiting condition

[0083] ④ The friction force generated by the pulley or shaft of the tooling when the mast is rising or falling needs to be considered.

[0084] If the side pull point is lower than the tooling height, the tooling height is used as the dividing line, and two processes need to be considered. When the sail is raised, the first process (recorded as P 1) From the lowest side pull point height to the tooling point height, the second process (recorded as P 2) The height of the mast is from the height of the workpiece to the maximum hoisting height of the sail. Figure 1 The position shown changes to Figure 2 When the sail is lowered, the above process is reversed, that is, the first process (denoted as P 3) The sail moves from the maximum lifting height to the height of the tooling point. The second process (recorded as P 4) The height of the tooling point runs to the lowest side pull point height, that is, the height of the mast is Figure 2 The position shown changes to Figure 1 Position shown.

[0085] If the side pull point is higher than the tooling height, only consider the sail rise. P 2 process, when considering the sail lowering, only consider P 3 process.

[0086] because F 1 Tension is formed after passing through the wire rope and the fixed pulley F 2 acts on the mast, taking into account the rolling friction of the fixed pulley, F 2 and F 1 is expressed as the following formula. In the analysis, the selection of Δ is determined through the specific rising and falling process.

[0087] F 2=Δ F 1

[0088] Where Δ is the coefficient between the gravity formed by the weight after considering the friction generated by the pulley or shaft of the tooling when the mast is raised or lowered and the tension on the actual side pulling point, and is expressed as follows.

[0089] Since the motion mode of the pulley or shaft of the tooling is rotation, so m is the rolling friction coefficient.

[0090] 4) Counterweight calculation:

[0091] (1) Ascending condition

[0092] Calculation process P1

[0093] ① Calculation i The cosine and sine of

[0094]

[0095] ② The counterweight is subject to the restriction of horizontal force component

[0096] As mentioned above, for the horizontal component, we have F 2• cosθ= Δ F 1• cosθ ≤ F x ,in F x = T 1+ T 2. Therefore, the tension in the counterweight calculation F 1 and horizontal force F x There are the following relationships:

[0097]

[0098] Combining formula (1), formula (2) and formula (3), we can get:

[0099]

[0100] ③Conditions under which the counterweight is subject to the vertical force component

[0101] As mentioned above, for the vertical component, we have F 2• sinth =Δ F 1• sinth ≤ F v + f ,in F v = G 1+ G 2, f=f 1+ f 2= λT 1+ λT 2. Therefore, the tension in the counterweight calculation F 1 has the following relationship with the vertical component:

[0102] Δ F 1• sinth ≤( G 1+ G 2)+( f 1+ f 2)

[0103] F 1≤(( G 1+ G 2)+ l ( T 1+ T 2)) / (Δ• sinth )

[0104] Combining formula (1), formula (2) and formula (3), we can get:

[0105]

[0106] ④The counterweight is subject to the constraints of the total bending moment

[0107] As mentioned above, for the bending moment, we have F 2• Z • cosθ ≤ M ,in M = M 1+ M 2. Therefore, the tension in the counterweight calculation F 1 and total bending moment M There are the following relationships:

[0108] Δ F 1• Z • cosθ ≤ M 1+ M 2

[0109] F 1≤( M 1+ M 2) / (Δ• Z • cosθ )

[0110] Combining formula (1), formula (2) and formula (3), we can get:

[0111]

[0112] Calculation process P2

[0113] ① Calculation i The cosine and sine of

[0114]

[0115] ② The counterweight is subject to the restriction of horizontal force component

[0116] As mentioned above, for the horizontal component, we have F 2• cosθ= Δ F 1• cosθ ≤ F x ,in F x = T 1+ T 2. Therefore, the tension in the counterweight calculation F 1 and horizontal force F x There are the following relationships:

[0117] ΔF 1• cosθ ≤ T 1+ T 2

[0118] F 1≤( T 1+ T 2) / (Δ• cosθ )

[0119] Combining equation (1), equation (7) and equation (8), we can get:

[0120]

[0121] ③Conditions under which the counterweight is subject to the vertical force component

[0122] As mentioned above, for the vertical component, we have F 2• sinth =Δ F 1• sinth ≤ F v + f ,in F v = G 1+ G 2, f=f 1+ f 2= λT 1+ λT 2. Therefore, the tension in the counterweight calculation F 1 has the following relationship with the vertical component:

[0123] Δ F 1• sinth ≤( G 1+ G 2)+( f 1+ f 2)

[0124] F 1≤(( G 1+ G 2)+ l ( T 1+ T 2)) / (Δ• sinth )

[0125] Combining equation (1), equation (7) and equation (8), we can get:

[0126]

[0127] ④The counterweight is subject to the constraints of the total bending moment

[0128] As mentioned above, for the bending moment, we have F 2• Z• cosθ ≤ M ,in M = M 1+ M 2. Therefore, the tension in the counterweight calculation F 1 and total bending moment M There are the following relationships:

[0129] Δ F 1• Z • cosθ ≤ M 1+ M 2

[0130] F 1≤( M 1+ M 2) / (Δ• Z • cosθ )

[0131] Combining equation (1), equation (7) and equation (8), we can get:

[0132]

[0133] For different side pull point conditions, if the rising process includes process P1 and process P2, then the results calculated by equations (4)(5)(6)(9)(10)(11) are taken as the minimum value of these results. F 1, which is the side pull load under the lifting condition; if the lifting process only satisfies P2, that is, the height of the side pull point is always higher than the tooling height, then the results calculated by equations (9), (10), and (11) are taken as the minimum value of these results. F 1.

[0134] (2) Descending condition

[0135] Calculation process P3

[0136] ① Calculation i The cosine and sine of

[0137]

[0138] ② The counterweight is subject to the restriction of horizontal force component

[0139] As mentioned above, for the horizontal component, we have F 2• cosθ= Δ F 1• cosθ ≤ F x ,in F x = T 1+ T 2. Therefore, the tension in the counterweight calculationF 1 and horizontal force F x There are the following relationships:

[0140] Δ F 1• cosθ ≤ T 1+ T 2

[0141] F 1≤( T 1+ T 2) / (Δ• cosθ )

[0142] Combining equation (1), equation (12) and equation (13), we can get:

[0143]

[0144] ③Conditions under which the counterweight is subject to the vertical force component

[0145] As mentioned above, for the vertical component, we have F 2• sinth =Δ F 1• sinth ≤ F v + f ,in F v = G 1+ G 2, f=f 1+ f 2= λT 1+ λT 2. Therefore, the tension in the counterweight calculation F 1 has the following relationship with the vertical component:

[0146] Δ F 1• sinth ≤( G 1+ G 2)+( f 1+ f 2)

[0147] F 1≤(( G 1+ G 2)+ l ( T 1+ T 2)) / (Δ• sinth )

[0148] Combining equation (1), equation (12) and equation (13), we can get:

[0149]

[0150] ④The counterweight is subject to the constraints of the total bending moment

[0151] As mentioned above, for the bending moment, we have F 2• Z • cosθ ≤ M ,in M = M 1+ M 2. Therefore, the tension in the counterweight calculation F 1 and total bending moment M There are the following relationships:

[0152] Δ F 1• Z • cosθ ≤ M 1+ M 2

[0153] F 1≤( M 1+ M 2) / (Δ• Z • cosθ )

[0154] Combining equation (1), equation (12) and equation (13), we can get:

[0155]

[0156] Calculation process P4

[0157] ① Calculation i The cosine and sine of

[0158]

[0159] ② The counterweight is subject to the restriction of horizontal force component

[0160] As mentioned above, for the horizontal component, we have F 2• cosθ= Δ F 1• cosθ ≤ F x ,in F x = T 1+ T 2. Therefore, the tension in the counterweight calculation F 1 and horizontal force F x There are the following relationships:

[0161] Δ F 1• cosθ ≤ T 1+ T 2

[0162] F 1≤( T 1+ T 2) / (Δ• cosθ )

[0163] Combining equation (1), equation (17) and equation (18), we can get:

[0164]

[0165] ③Conditions under which the counterweight is subject to the vertical force component

[0166] As mentioned above, for the vertical component, we have F 2• sinth =Δ F 1• sinth ≤ F v + f ,in F v = G 1+ G 2, f=f 1+ f 2= λT 1+ λT 2. Therefore, the tension in the counterweight calculation F 1 has the following relationship with the vertical component:

[0167] Δ F 1• sinth ≤( G 1+ G 2)+( f 1+ f 2)

[0168] F 1≤(( G 1+ G 2)+ l ( T 1+ T 2)) / (Δ• sinth )

[0169] Combining equation (1), equation (17) and equation (18), we can get:

[0170]

[0171] ④The counterweight is subject to the constraints of the total bending moment

[0172] As mentioned above, for the bending moment, we have F 2• Z • cosθ ≤ M ,in M = M 1+M 2. Therefore, the tension in the counterweight calculation F 1 and total bending moment M There are the following relationships:

[0173] Δ F 1• Z • cosθ ≤ M 1+ M 2

[0174] F 1≤( M 1+ M 2) / (Δ• Z • cosθ )

[0175] Combining equation (1), equation (17) and equation (18), we can get:

[0176]

[0177] For different side pull point conditions, if the descent process includes process P3 and process P4, then the results calculated by equations (14)(15)(16)(19)(20)(21) are taken as the minimum value of these results. F 1, which is the side pull load under the descending condition; if the descending process only satisfies P3, that is, the height of the side pull point is always higher than the tooling height, then the results calculated by equations (14), (15), (16) are taken as the minimum value of these results F 1.

[0178] In summary, the load of the sail in the side-pull test can be determined, and further restrictions can be added according to the control method of the sail itself to simulate the actual working conditions.

[0179] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for obtaining counterweight for a lifting test in a land-based test of a large sail, characterized in that: The steps include: S1. Confirm the following parameters through design and actual situation: Weight load: including the weight of each mast section, mechanical components and sail surface above the side pull point, recorded as G 1; Inertia load: including vertical forces of masts, mechanical components and sails above the side pull point G 2. Lateral forces on masts, mechanical components and sails above each side pull point T 1. Bending moment value at the overlap of each mast section M 1 and friction f 1; Wind load: The lateral force on the sail caused by wind load T 2, and the bending moment value caused by the lateral force M 2 and friction f 2; Horizontal load: T 1+ T 2; Vertical load: F v + f ,in F v is the weight of each sail component and the vertical force caused by the vertical inertia load on each component. F v = G 1+ G 2; f is the friction force generated by the relative motion of the mast. If the sliding friction coefficient is λ , f=f 1+ f 2= λT 1+ λT 2; Bending moment: M , is the bending moment caused by the horizontal inertia load and the bending moment caused by the lateral force of the wind, M = M 1+ M 2; S2. Determine the load state simulated by the side pull test; The vertical distance between the side pull point and the tooling point is h 1. The lowest side pull point is N. At this time, the angle between the side pull wire rope A and the horizontal is θ , the distance between the center of the sail and the tooling pulley D is L ; The vertical distance between the side pull point and the tooling point is h 2. The tooling point is M. At this time, the angle between the side pull wire rope A and the horizontal is θ , the distance between the center of the sail and the tooling pulley D is L ; F 1 is the weight of the object, which forms a pulling force after passing through the wire rope and the fixed pulley F 2 acts on the mast, then F The horizontal component of force 2 is F 2• cosθ , the vertical component is F 2• sinθ The bending moment at the root is F 2• Z • cosθ ; S3, decomposing the side-pull process and obtaining the counterweight; When the sail is raised, the first process is recorded as P 1. Run from the lowest side pull point height to the tooling point height; The second process is recorded as P 2; from the height of the tooling point to the maximum lifting height of the sail; when the sail is lowered, the third process is recorded as P 3, the sail runs from the maximum lifting height to the height of the tooling point; the fourth process is recorded as P 4. The height of the tooling point runs to the lowest side pull point height; In process P1, the counterweight is subject to the following constraints on the horizontal component of force: μ is the rolling friction coefficient of the load clamped in the pulley used; The counterweight is subject to the constraints of the vertical force in process P1: The counterweight is subject to the constraints of the total bending moment in process P1: For the P1 process, Z is the height of the mast from the lowest side-pull point after it is raised; In process P2, the counterweight is subject to the following constraints on the horizontal component of force: The counterweight is subject to the constraints of the vertical force in process P2: The counterweight is subject to the constraints of the total bending moment in process P2: For the P2 process, Z is the height of the mast from the tooling point after it is raised; The minimum value among the results calculated by equations (4)(5)(6)(9)(10)(11) is taken as F 1, which is the side pull load under the lifting condition; if the lifting process only satisfies P2, that is, the height of the side pull point is always higher than the tooling height, then the results calculated by equations (9), (10), and (11) are taken as the minimum value of these results. F 1; In process P3, the counterweight is subject to the following constraints on the horizontal component of force: The counterweight is subject to the constraints of the vertical force in process P3: The counterweight is subject to the constraints of the total bending moment in process P3: For the P3 process, Z is the height of the mast from the tooling point after it is lowered; In process P4, the counterweight is subject to the following constraints on the horizontal component of force: The counterweight is subject to the constraints of the vertical force in process P4: The counterweight is subject to the constraints of the total bending moment in process P4: For the P4 process, Z is the height of the mast from the lowest side-pull point after it is lowered; The minimum value of the results calculated by equations (14)(15)(16)(19)(20)(21) is taken as F1, which is the side pull load under the descent condition. If the descent process only satisfies P3, that is, the height of the side pull point is always higher than the tooling height, then the minimum value of the results calculated by equations (14)(15)(16) is taken as F1. Finally, the load on the sail in the side-pull test was determined.

2. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 1 is characterized in that: The inertia load in step S1 includes a vertical inertia load and a lateral inertia load.

3. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 2 is characterized in that: In step S1, the vertical force G2 of each section of the mast, mechanical component, and sail surface above the side pull point can be obtained through the maximum vertical acceleration aV of the ship where the sail is located, according to aV and the weight of the component.

4. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 2 is characterized in that: In step S1, the lateral force T1 of each component can be obtained through the maximum lateral acceleration aL of the ship where the sail is located and the weight of the component.

5. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 1, characterized in that: The wind load in step S1 and the cross-sectional airfoil of the sail are used to obtain the total force on the sail surface through numerical calculation or wind tunnel test, and then the lateral force T2 caused by the wind load is obtained according to the calculated area ratio of the sail surface, and the bending moment value M2 and friction force f2 caused by the lateral force are obtained.

6. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 1, characterized in that: In step S3, if the height of the side-pull point is higher than the height of the tooling, when the sail is raised, only the P2 process is considered, and when the sail is lowered, only the P3 process is considered.

7. The method for obtaining the counterweight of the lifting test in the land-based test of a large sail according to claim 1, characterized in that: After step S3, according to the control method of the sail, restriction conditions are added to simulate the actual working conditions.

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