A marine sandwich structure gangway and method thereof

Abstract

The present invention relates to a marine sandwich-structured gangplank and a method thereof. The gangplank comprises a sandwich layer, an H-profile, and a channel-shaped profile. The channel-shaped profile forms a channel-shaped frame, with an H-profile connected between the two ends of the channel-shaped frame. Multiple continuous sandwich layers are fixedly connected within the channel-shaped frame to form a gangplank body. The gangplank body is provided with multiple anti-slip strips along its length, and a plurality of arc-shaped pads are provided along its length on its back. Under the same load and deformation conditions, the overall weight of the gangplank is significantly reduced compared to a gangplank made of only sandwich layer material or only metal, facilitating transportation and loading. The channel-shaped profiles arranged around the periphery of the sandwich-structured gangplank and the H-profile arranged in the middle effectively constrain the deformation and dimensional stability of the gangplank's sandwich layer, providing a continuous, strong load-bearing structure and improving the gangplank's operational stability and reliability. The present invention provides a gangplank weight control method based on deflection deformation, which reduces weight and controls material costs while meeting standard deflection requirements.

Description

Technical Field

[0001] The invention relates to a ship gangway, in particular to a ship sandwich structure gangway and a weight control method thereof. Background Art

[0002] During vessel operation, gangplanks are used to move between ship and shore, between ships, and between ships and offshore structures, enabling the exchange of materials and personnel. In particular, some government vessels or special-purpose vessels require the active deployment of gangplanks from the mother ship to docks, mooring vessels, offshore structures, and other locations. Due to the vessel's center of gravity, the limited number of crew members, and the need for gangplanks to be stored and used in the superstructure, a lightweight, relatively large, and compact gangplank is required for personnel transfer and boarding. The CB*3116-1982 "Aluminum Gangplank" has a complex structure, heavy weight, and a large minimum length, making it unsuitable for storage and use in confined spaces. Summary of the Invention

[0003] In order to enable a single person or as few people as possible to move and board a gangway, control the deadweight of the gangway, increase the load per unit area of ​​the gangway, reduce the spatial size of the gangway, and make the gangway suitable for use under conditions of relative swaying of the ship, the present invention proposes a marine sandwich structure gangway and a method thereof.

[0004] In order to solve the above problems, the present invention adopts the following technical solutions:

[0005] A marine sandwich structure gangway comprises a sandwich layer, an H-profile, and a groove profile. The groove profile forms a groove frame, an H-profile is connected between the two ends of the groove frame, and a plurality of continuous sandwich layers are fixedly connected in the groove frame to form a gangway body. A plurality of anti-slip strips are arranged on the top of the gangway body along the length direction, and a plurality of arc-shaped pads are arranged on the back side along the length direction.

[0006] Furthermore, the total length L of the marine sandwich structure gangway is 300 mm to 700 mm, the width B can accommodate one person walking, the thickness t satisfies the stiffness of the area within the size of a single person's footprint under concentrated load, and the sandwich layer structure meets the load test requirements of "CB*3116-1982, Aluminum Gangway" or reduces the allowable deformation range under load.

[0007] Furthermore, the sandwich layer consists of a left sandwich layer and a right sandwich layer, the width B of a single sandwich layer is between 150mm and 350mm, and the long side of the sandwich layer has a processed convex groove to adapt to the groove profile and the H-profile groove; the convex groove of the sandwich layer is coated with flexible glue and embedded in the H-profile groove.

[0008] Furthermore, the trough frame composed of the trough profile consists of a left trough profile, a right trough profile, an upper trough profile, and a lower trough profile. The convex groove of the sandwich layer is smeared with flexible glue and embedded in the groove of the trough profile. The left trough profile, the right trough profile, the upper trough profile, and the lower trough profile are nested around the sandwich layer.

[0009] Furthermore, the H-profile is made of high-strength and lightweight metal, which reduces the weight and overall height of the H-profile while ensuring strength; the trough profile is made of high-strength and lightweight metal, which reduces the weight and overall height of the trough profile while ensuring strength.

[0010] Furthermore, the anti-slip strip is composed of a hollow metal with several protruding strips arranged around it. The spacing L1 between the anti-slip strips is the length of a step taken by a person approaching. The material of the anti-slip strip is the same as that of the H-profile and the groove profile to achieve welding connection.

[0011] Furthermore, the H-profile and the groove profile are connected by welding at the end joints, the anti-slip strip is connected to the H-profile and the groove profile at the joints by welding, and the bottom surface of the anti-slip strip is in the same plane as the sandwich layer, the H-profile and the groove profile upper end surface.

[0012] Furthermore, the arc-shaped pad is welded to the H-profile and the groove profile, and the arc-shaped pad is made of the same material as the H-profile and the groove profile to achieve welding.

[0013] A method for controlling the weight of a marine sandwich structure gangway comprises the following steps:

[0014] S1. Determine the design requirements for the springboard length L, the springboard's deadweight W2, and the maximum deflection allowed by the specification ω;

[0015] S2. Based on the material properties and existing springboard data, initially select the core layer thickness t, springboard width B, and profile thickness a. Based on the springboard length L, select the corresponding standard ballast load W1; the core layer deadweight W is calculated from the selected core layer thickness t and springboard width B. 21 ; According to the sandwich layer weight W2, the maximum acceptable weight of the profile is W 22max ,

[0016] S3. Calculate the design uniform load Q of the gangway from the ballast load W1 and the core weight W2.

[0017]

[0018] Where: W 22 is the actual weight of the profile;

[0019] S4. Calculate Q1 from the elastic modulus E1 of the core material, the width B of the springboard, the thickness t of the core, and the maximum deflection ω allowed by the specification. Calculate Q2 from Q and Q1.

[0020] The maximum deflection at the center of the springboard is calculated according to formula (3) based on the material mechanics.

[0021] (3)

[0022] in: , is the uniformly distributed load on the core layer, is the uniformly distributed load on the profile, is the moment of inertia of the core layer;

[0023] S5. Calculate the profile's moment of inertia I2 based on the springboard length L, the profile's uniformly distributed load Q2, the profile's elastic modulus E2, and the specification's maximum allowable deflection ω. Calculate b from I2.

[0024] From the mechanics of materials, we know that the central part of the springboard The maximum deflection at is calculated according to formula (4):

[0025] (4)

[0026] , (5)

[0027] in: is the moment of inertia of the H-profile, is the moment of inertia of the channel profile;

[0028] According to the generally accepted knowledge of materials mechanics 21 is a ternary function of (b, h, a), I 22 It is also a three-variable function of (b, h, a), where a is the thickness of the profile, which is a known value. The profile height h is the same as the total thickness of the springboard t1. Therefore, from equations (4) and (5), we know that I2 is a one-variable function of b, I2(b), which is only related to the wing width 2b of the H-profile 2 and the wing width b of the slot profile. For the known I2, one or several b can be solved. According to the actual engineering practice, the smallest real number b is taken as the value of the width b;

[0029] If t / 2>b, the thickness a of the profile or the thickness t of the sandwich layer is reduced, and the step flows to S2; if B / 2<b, the thickness a of the profile or the thickness t of the sandwich layer is increased, and the step flows to S2;

[0030] S6. The actual weight W of the profile is calculated from the springboard length L, profile thickness a, and trough profile wing width b. 22 If W 22 Greater than W 22max , reduce the width B or replace the profile or sandwich layer with high strength and low density, and the step flows to S2;

[0031] S7. Determine the sandwich layer, profile material, springboard width B, profile thickness a, trough profile wing width b, and sandwich layer thickness t. At this point, the weight of the springboard is controlled while meeting the design requirements.

[0032] A method for using a marine sandwich structure gangway, comprising the following steps:

[0033] S1. When the operating vessel is close to the target vessel or structure, move the gangplank and connect one end of the gangplank to the side structure of the target vessel so that the curved pad is within the deck surface of the target vessel.

[0034] S2. Lower the gangplank at one end of the workboat. At this time, the sandwich structure gangplank is completed between the workboat and the target ship.

[0035] Beneficial effects of the present invention:

[0036] (1) Under the condition of the same load and deformation, the overall weight of the sandwich structure springboard is greatly reduced compared with the springboard made of only sandwich layer material or only metal springboard, which is convenient for people to carry and transport.

[0037] (2) The trough profiles arranged around the sandwich structure springboard and the H profiles arranged in the middle effectively constrain the deformation and dimensional stability of the springboard sandwich layer, providing a continuous strong force-bearing structure, and the springboard has better stability and reliability in use.

[0038] (3) A springboard weight control method based on deflection deformation is proposed to reduce weight and control material cost while meeting the specified deflection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the front view of the springboard;

[0040] Figure 2 It is the springboard AA view;

[0041] Figure 3 This is the view from the springboard A;

[0042] Figure 4 This is the rear view of the springboard;

[0043] Figure 5 Schematic diagram of sandwich layer size and profile size;

[0044] Figure 6 It is the force diagram of the springboard;

[0045] Figure 7 This is a schematic diagram of the weight control process;

[0046] Figure 8 Indicates when used as a springboard Figure 1 ;

[0047] Figure 9 Indicates when used as a springboard Figure 2 ;

[0048] Explanation of reference numbers: 1: core layer, 1-1: right core layer, 1-2: left core layer, 2: H-profile, 3: channel profile, 3-1: left channel profile, 3-11: left channel profile surface, 3-12: left channel profile bottom, 3-13: left channel profile side, 3-2: right channel profile, 3-3: upper channel profile, 3-4: lower channel profile, 4: anti-slip strip, 6: arc pad, B: springboard width, H1: anti-slip strip height, t: total thickness of springboard, thickness of core layer, Q: total uniform load, Q1: uniform load on core layer, Q2: uniform load on profile, W1: design load, W2 : deadweight of the springboard, W21: deadweight of the sandwich layer, W22: deadweight of the metal profile, E1: elastic modulus of the core layer, E2: elastic modulus of the profile, I1: moment of inertia of the core layer, I2: moment of inertia of the profile, I21: moment of inertia of the H profile, I22: moment of inertia of the channel profile, a: profile thickness, b: width of the channel profile wing, ω: maximum deflection of the springboard length L when subjected to a specified load; profile height h. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0050] like Figures 1 to 6 As shown, a marine sandwich-structured gangplank of the present invention comprises a sandwich layer 1, an H-profile 2, and a channel-shaped member 3. The channel-shaped member 3 forms a channel-shaped frame, the ends of which are connected and fixed by H-profiles 2. Multiple continuous sandwich layers 1 are fixedly connected within the channel-shaped frame to form the gangplank body. The gangplank body is provided with multiple anti-slip strips 4 along its length, and multiple curved pads 6 along its back. Under conditions of equivalent load and deformation, this sandwich-structured gangplank significantly reduces its overall weight compared to gangplanks made solely of sandwich layer material or metal, facilitating easier transport and loading.

[0051] Marine sandwich-structured gangplanks have an overall length of L, an overall width of B, and a thickness of t. Width B should be wide enough for one person to walk through, typically between 300mm and 700mm. The overall length L is determined based on requirements, while the thickness t should provide sufficient stiffness to withstand concentrated loads within the footprint of a single person. The sandwich structure must also meet the load test requirements of CB*3116-1982, "Aluminum Gangplanks," or reduce the allowable deformation range under load.

[0052] Use multiple continuous sandwich layers 1. The preferred sandwich layer 1 is composed of a left sandwich layer 1-2 and a right sandwich layer 1-1. The width of a single sandwich layer is B, which is preferably between 150mm and 350mm. If the width of the sandwich layer is similar to the size of B, the cost of the sandwich layer will increase several times and it will be unfavorable to arrange the middle H-profile. If the width of the sandwich layer is too narrow, too many joints will affect the strength of the sandwich structure springboard. The two long sides of the sandwich layer 1 have processing grooves to adapt to the groove profile 3 and the H-profile 2. Figure 2 shown.

[0053] H-profile 2 structure, such as Figure 2 As shown, the protruding end of the core layer 1 is coated with flexible glue and then embedded in the groove of the H-profile 2. The flexible glue maintains a bond even after the core layer 1 and the H-profile 2 are displaced relative to each other after the springboard is subjected to force, thereby improving overall strength. The H-profile 2 is preferably made of a high-strength, lightweight metal such as titanium alloy or aluminum alloy, ensuring strength while reducing weight. The overall height of the H-profile is t1.

[0054] The channel profile 3 forms a channel frame structure, such as Figure 1 , as shown in 2, it consists of a left channel profile 3-1, a right channel profile 3-2, an upper channel profile 3-3, and a lower channel profile 3-4. The protruding end of the sandwich layer 1 is smeared with flexible glue and embedded in the groove of the channel profile 3. The left channel profile 3-1, the right channel profile 3-2, the upper channel profile 3-3, and the lower channel profile 3-4 are nested around the sandwich layer 1. The flexible glue still has a bonding effect after the sandwich layer 1 and the channel profile 3 are relatively misaligned after the springboard is subjected to force, thereby improving the overall rigidity. The channel profile 3 is preferably a high-strength lightweight metal, such as titanium alloy, aluminum alloy, etc., to ensure strength while reducing weight. The overall height of the channel profile is t1.

[0055] Anti-slip strip 4 structure, such as Figure 2 As shown in Figure 3, a hollow metal is provided with several protruding strips around it to increase the anti-slip effect. The anti-slip strips 4 should be made of the same material as the H-profile 2 and the trough profile 3 to achieve a welded connection. The spacing between the anti-slip strips 4 is L1, and the size of L1 should be close to the length of a person's step, about 500mm.

[0056] The ends of the H-profile 2 and the trough profile 3 are welded together. The anti-slip strip 4 is also welded to the H-profile 2 and trough profile 3. The bottom surface of the anti-slip strip 4 is flush with the upper surfaces of the core layer 1, H-profile 2, and trough profile 3. This integrally welded metal frame structure effectively improves the overall rigidity of the sandwich structure springboard. The trough profile 3 surrounding the core layer 1 effectively limits deformation behind the core layer 1, preventing instability and deformation under load. The H-profile 2 positioned in the center of the springboard ensures nonlinear deformation under load, ensuring relatively minimal deformation under certain load conditions.

[0057] Arc-shaped pads 6 of a certain thickness are installed on the back of each end of the ramp. These pads 6 are welded to the H-profile 2 and the channel profile 3. These pads 6 are preferably made of the same material as the H-profile 2 and the channel profile 3 to facilitate welding. These pads transform the relative motion between the ramp and the deck from sliding friction to rolling friction, reducing damage to the contact surface. The protruding pads 6 prevent the ramp from sliding outward and separating from the ship's main structure when the span of the ramp increases due to rocking between the two ships.

[0058] When initially designing and verifying the required springboard's strength, the length, width, material, elastic modulus, and density are all known and must meet the load, ballast, and deflection requirements of CB*3116. Appropriate springboard materials, springboard thickness t, and profile thickness a must be selected. For engineering applications and cost control, the required profiles can be made from bent or welded sheet metal, with uniform sheet thickness. The web and flange thicknesses of the H-section 2 and the channel section can be the same thickness as the sheet metal, a. For engineering applications and common sense, to ensure the sandwich structure has sufficient strength and rigidity to withstand relatively small-area loads, the core thickness t is selected within a certain range. Depending on the raw material preparation and processing cost, the core thickness t is generally an integer between 20 and 60 mm. For weight control, a known integer value can be selected for verification calculations. In this case, the height of the H-section 2 and channel section 3, as well as the core thickness, is t. In order to ensure that the sandwich layer 1 is uniformly constrained on all sides, it is preferred that the depth of the sandwich layer 1 embedded in the profile is the same. The preferred width of the groove profile wing is b, and the width of the H profile wing is 2b. Figure 5 shown

[0059] According to the standard requirements and design premise, the springboard load distribution is as follows Figure 6 As shown; the ladder load formula is shown in formula (1)

[0060] (1)

[0061] in: The standard requires that the load is uniformly distributed. For a springboard with a selected length L and width B, the sandwich layer thickness t that meets the local load stiffness requirements is selected based on experience and material properties. At this time, the weight of the sandwich layer is It can be calculated as a known value. In order to achieve single-person or as few-person handling as possible, the design requires that the maximum weight per unit length of the springboard can be a fixed value. For example, the springboard is 10kg per meter. At this time, the maximum weight that the profile can accept is .

[0062] The central part of the springboard ( ) is calculated according to formula (2):

[0063] (2)

[0064] in:

[0065] (3)

[0066] That is, the uniformly distributed load on the core layer Uniformly distributed load on the profile The deflection generated by each Same, and and The sum of the springboard design uniform load is the elastic modulus of the selected sandwich material. is a known value, the springboard width B and the sandwich layer thickness t are selected as known values, and the sandwich layer 1 and the H-profile 2 and the groove profile 3 are connected with adhesive glue and can be regarded as a whole. From formula (2), we can get Value, according to formula (1) and (3), we can get .

[0067] According to the material mechanics, the central part of the springboard ( ) is calculated according to formula (4):

[0068] (4)

[0069] in:

[0070] (5)

[0071] That is, the moment of inertia of the H-profile With channel profile 3 and moment of inertia In the case of uniform load Make the springboard produce maximum deflection .

[0072] According to the generally accepted knowledge of materials mechanics 21 is a ternary function of (b, h, a), I 22 It is also a three-variable function of (b, h, a), where a is the thickness of the profile selected as a known value, and the profile height h is the same as the total thickness of the springboard t1. Therefore, from equations (4) and (5), we know that I2 is a one-variable function of b I2(b), which is only related to the wing width 2b of the H profile 2 and the wing width b of the groove profile. For the known I2, one or several b can be solved. According to the actual engineering practice, the smallest real number b is taken as the value of the width b. For the selected profile material elastic modulus is a known value, the springboard width B, the profile thickness a and the sandwich layer thickness t are selected known values. It is only related to the width 2b of the H-profile wing and the width b of the trough profile wing. The value of width b can be obtained from equations (4) and (5).

[0073] Based on the calculated width b, the preferred width b is greater than 2 / t to ensure that the sandwich layer 1 is firmly fixed in the profile. If the width is less than t / 2, the profile thickness a or the sandwich layer thickness B needs to be reduced. The preferred width b is less than B / 2 to ensure that the wings of the H-profile 2 and the channel profile 3 do not overlap. If the obtained width b is greater than B / 2, the profile thickness a needs to be increased to reduce the width b. The actual weight of the springboard profile can be further calculated from the obtained width b. , and the maximum acceptable deadweight Compare. ≤ , then each value meets the design value requirements and the cross-sectional area of ​​the profile is relatively small, and the corresponding weight is the smallest; if > , can be increased by reducing the springboard width B , or use high-strength, low-density profiles or sandwich layers to achieve weight control;

[0074] like Figure 8 , 9 shows the method for using the springboard of the present invention:

[0075] S1. When the operating vessel is relatively close to the target vessel or structure, the gangway is moved and one end of the gangway is overlapped with the side structure of the target vessel so that the pad 6 is within the deck surface of the target vessel.

[0076] S2. Lower the gangplank at one end of the workboat. At this time, the sandwich structure gangplank is completed between the workboat and the target ship.

[0077] The springboard weight control method of the present invention is as follows: Figure 7 The flow chart is shown as follows:

[0078] S1. Determine the design requirements for the springboard length L, the springboard's deadweight W2, and the maximum deflection ω allowed by the specification;

[0079] S2. Based on the material properties and existing springboard big data learning results, initially select the sandwich layer thickness t, springboard width B, and profile thickness a. Based on the springboard length L, select the ballast load W1 corresponding to the specification requirements;

[0080] S3. Determine the core weight W from the selected t and B 21 According to W2, the maximum acceptable weight W of the profile is obtained 22max . From W1 and W2, we can get Q;

[0081] S4. From E1, B, t, and ω, we can derive Q1. From Q and Q1, we can derive Q2.

[0082] S5. Calculate I2 from L, Q2, E2, and ω, and calculate b from I2. If t / 2 > b, reduce the profile thickness a or the core thickness t, and proceed to S2. If B / 2 < b, increase the profile thickness a or the core thickness t, and proceed to S2.

[0083] S6. Calculate the actual weight W of the profile from L, a, and b 22 If W 22 Greater than W 22max It is preferred to reduce the width B or replace the profile or sandwich layer with one having high strength and low density. The step flows to S2.

[0084] S7. Determine the core layer, profile material, and dimensions B, a, b, and t. At this point, the weight of the springboard has been controlled while meeting design requirements.

Claims

1. A method for controlling the weight of a marine sandwich-structured gangplank, comprising a sandwich layer, an H-shaped profile, and a channel-shaped profile. The channel-shaped profile forms a channel frame, and an H-shaped profile is connected between the ends of the channel-shaped frame. Multiple continuous sandwich layers are fixedly connected within the channel-shaped frame to form a gangplank body. The gangplank body is provided with multiple anti-slip strips along its length and multiple arc-shaped pads along its back. The method is characterized by: The steps of this method are: S1. Determine the design requirements for the springboard length L, the springboard's deadweight W2, and the maximum deflection allowed by the specification ω; S2. Based on the material properties and existing springboard data, initially select the core layer thickness t, springboard width B, and profile thickness a. Based on the springboard length L, select the corresponding standard ballast load W1; the core layer deadweight W is calculated from the selected core layer thickness t and springboard width B. 21 ; According to the sandwich layer weight W 21 The maximum acceptable weight W of the profile is obtained 22max , S3. Calculate the design uniform load Q of the springboard based on the ballast load W1 and the springboard's deadweight W2. （1） （2） Where: W 22 is the actual weight of the profile; S4. Calculate Q1 from the elastic modulus E1 of the core material, the width B of the springboard, the thickness t of the core, and the maximum deflection ω allowed by the specification. Calculate Q2 from Q and Q1. From the mechanics of materials, we know that the central part of the springboard The maximum deflection at is calculated according to formula (3): （3） in: , is the uniformly distributed load shared by the sandwich layer, is the uniformly distributed load shared by the profile, is the moment of inertia of the core layer; S5. Calculate the profile's moment of inertia I2 based on the springboard length L, the uniformly distributed load Q2 shared by the profile, the profile material's elastic modulus E2, and the specification's maximum allowable deflection ω. From I2, calculate the channel profile's wing width b and the H-profile's wing width 2b. From the mechanics of materials, we know that the central part of the springboard The maximum deflection at is calculated according to formula (4): (4) (5) in: is the moment of inertia of the H-profile, is the moment of inertia of the channel profile; From the mechanics of materials, we know 21 is a ternary function of (b, h, a), I 22 It is also a three-variable function of (b, h, a), where a is the thickness of the profile, which is a known value. The profile height h, the sandwich layer thickness t, and the total thickness of the springboard t1 are the same. Therefore, from Equations (4) and (5), we know that I2 is a one-variable function of b I2(b), that is, I 2= f(b) is only related to the flange width 2b of the H-profile and the flange width b of the channel profile. Given I2, one or more b values ​​can be solved. The smallest real number b is taken based on actual engineering practice as the value of the available width b. If t / 2>b, the profile thickness a or the core thickness t is reduced, and the process proceeds to S2. If B / 2<2b, the profile thickness a or the core thickness t is increased, and the process proceeds to S2. S6. The actual weight W of the profile is calculated from the springboard length L, profile thickness a, and trough profile wing width b. 22 If W 22 Greater than W 22max , reduce the width B or replace the profile or sandwich layer with high strength and low density, and the step flows to S2; S7. Determine the sandwich layer, profile material, springboard width B, profile thickness a, trough profile wing width b, and sandwich layer thickness t. At this point, the weight of the springboard is controlled while meeting the design requirements.

2. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The width B of the marine sandwich structure gangway is 300 mm to 700 mm, and the sandwich layer structure meets the requirements of "CB 3116-1982 "Aluminum Gangway".

3. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The sandwich layer consists of a left sandwich layer and a right sandwich layer. The width B of a single sandwich layer is between 150mm and 350mm. The long side of the sandwich layer has a processed convex groove to adapt to the groove profile and the H-profile groove; the convex groove of the sandwich layer is embedded in the H-profile groove after being coated with flexible glue.

4. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The trough frame composed of the trough profile consists of a left trough profile, a right trough profile, an upper trough profile, and a lower trough profile. The convex groove of the sandwich layer is embedded in the groove of the trough profile after being smeared with flexible glue. The left trough profile, the right trough profile, the upper trough profile, and the lower trough profile are nested around the sandwich layer.

5. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The H-profile is made of high-strength and lightweight metal, which reduces the weight and overall height of the H-profile while ensuring strength; the trough profile is made of high-strength and lightweight metal, which reduces the weight and overall height of the trough profile while ensuring strength.

6. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The anti-slip strip is composed of a plurality of protruding strips arranged around a hollow metal; the material of the anti-slip strip is the same as that of the H-profile and the groove profile to achieve welding connection.

7. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The H-profile and the groove profile are connected at their ends by welding, and the anti-slip strip is connected to the H-profile and the groove profile at their joints by welding, and the bottom surface of the anti-slip strip is in the same plane as the sandwich layer, the H-profile and the upper end surface of the groove profile.

8. The method for controlling the weight of a marine sandwich structure gangway according to claim 1, wherein: The arc-shaped pad is welded on the H-profile and the groove profile, and the arc-shaped pad is made of the same material as the H-profile and the groove profile to achieve welding.

9. A method for using a marine sandwich structure gangway, the marine sandwich structure gangway being manufactured by the weight control method for a marine sandwich structure gangway according to any one of claims 1 to 8, characterized in that: The steps are: S1. When the operating vessel is close to the target vessel or structure, move the gangplank and attach one end of the gangplank to the target vessel's side structure, ensuring that the curved pad is within the target vessel's deck surface. S2. Lower the gangplank at one end of the workboat. At this time, the sandwich structure gangplank is completed between the workboat and the target ship.

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