A hat-stiffened sandwich panel for a marine vessel and a method of manufacturing the same

Abstract

This invention discloses a cap-shaped rib structure for a ship composite sandwich panel, comprising a foam structure with embedded reinforcing ribs, a reinforcing rib skin layer, and a bolted connection structure. The foam structure with embedded reinforcing ribs is disposed within the reinforcing rib skin layer. The foam structure with embedded reinforcing ribs includes an embedded structure and a reinforcing rib foam structure, with the embedded structure disposed within the reinforcing rib foam structure and bonded for fixation. The reinforcing rib foam structure is fixed to the upper part of the sandwich panel structure. A bolted connection structure is provided on the embedded structure, with a connector passing through the top of the reinforcing rib skin layer and connecting to the bolted connection structure. This invention also provides a method for manufacturing the cap-shaped rib structure for a ship composite sandwich panel. The beneficial effects of this invention are: the embedded structure is designed within the cap-shaped reinforcing rib, which can effectively avoid stress concentration problems caused by large differences in material properties between the components of the sandwich structure and the embedded structure, ensuring the strength of the sandwich panel structure and improving its service life.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to a cap-shaped rib structure for a ship composite sandwich panel and its manufacturing method. Background Technology

[0002] Marine composite sandwich structures consist of two or more thin skin layers and a thicker, low-density core material. Materials suitable for the core include PVC foam, HCP foam, PMI foam, aramid honeycomb, and buoyancy materials. For full-height composite sandwich structures, if directly bolted to the structure to be connected, the load-bearing strength is insufficient under preload, causing the core to collapse. The traditional solution is to design the core layer in the connection area as a composite material or to embed metal structures within the composite material to enhance connection strength. However, the significant differences in properties between the components of the sandwich structure and the embedded materials can cause stress concentration at the interface between the embedded parts and the core layer. Under fatigue loads, this reduces the strength of the sandwich structure and shortens its service life. Furthermore, the design thickness of the composite sandwich panel and the bolt-through connection method limit the applicability of embedded designs. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a cap-shaped rib structure for ship composite sandwich panels and its manufacturing method, aiming to ensure the strength of the sandwich panels and improve their service life.

[0004] The technical solution adopted in this invention is: a cap-shaped rib structure for a ship composite sandwich panel, comprising a foam structure with pre-embedded reinforcing ribs, a reinforcing rib skin layer, and a bolt connection structure;

[0005] The foam structure containing pre-embedded reinforcing ribs is located within the reinforcing rib skin layer;

[0006] The foam structure with pre-embedded reinforcing ribs includes a pre-embedded structure and a reinforcing rib foam structure. The pre-embedded structure is located inside the reinforcing rib foam structure and is bonded and fixed.

[0007] The reinforcing foam structure is fixed to the upper part of the sandwich panel structure;

[0008] The embedded structure is provided with a bolt connection structure, and the connector passes through the top of the reinforcing rib skin layer and is connected to the bolt connection structure.

[0009] According to the above scheme, the reinforcing foam structure includes a cap-shaped reinforcing foam layer, and an installation groove for installing the pre-embedded structure is opened in the cap-shaped reinforcing foam layer.

[0010] According to the above scheme, the cross-section of the mounting groove is trapezoidal.

[0011] According to the above scheme, the pre-embedded structure includes a composite material main body with a cavity at the bottom, a composite material base plate, and a metal pre-embedded part; the composite material main body is placed in the installation groove, and the outer side is bonded and fixed to the cap-shaped reinforcing foam layer; the bottom of the composite material main body has a cavity, and the composite material base plate and the metal pre-embedded part are arranged sequentially from bottom to top in the cavity; the composite material base plate is located at the top of the sandwich panel structure.

[0012] According to the above scheme, the top of the composite material main body is flush with the cap-shaped reinforcing foam layers on both sides, and an interface bonding layer is formed between the side of the composite material main body and the cap-shaped reinforcing foam layers on both sides; the composite material base plate, the metal embedded part and both sides of the composite material main body are respectively in close contact with the cap-shaped reinforcing foam layers.

[0013] According to the above scheme, the angle between the two sides of the cavity and the inner bottom is 30-70°; the depth of the cavity is 20-60mm and the width is 40-100mm.

[0014] According to the above scheme, both the composite material main body and the composite material base plate are made of glass fiber reinforced resin laminate.

[0015] According to the above scheme, the sandwich panel structure includes a bottom skin layer, a foam core layer, and a top skin layer arranged sequentially from bottom to top.

[0016] According to the above scheme, grooves are respectively opened on the upper and lower surfaces of the foam core layer and the cap-shaped reinforcing foam layer along the horizontal and vertical directions, and the grooves are filled with resin.

[0017] The present invention also provides a method for manufacturing the cap-shaped rib structure of the ship composite sandwich structure as described above, the method comprising the following steps:

[0018] Fabrication of composite material body and composite material base plate:

[0019] Metal embedded parts processing:

[0020] The embedded structure is obtained by bonding and curing the metal embedded parts and the composite material base plate with the composite material body.

[0021] The embedded structure is bonded to the cap-shaped reinforcing foam to form a foam structure containing the embedded reinforcing ribs:

[0022] Vacuum forming, specifically includes the following steps:

[0023] Mold preparation:

[0024] According to the thickness requirements, a bottom layer of fiber cloth is laid in the mold, the foam core layer is placed on the laid fiber cloth layer, and a top layer of fiber cloth is laid on the foam core layer; then the foam structure containing the pre-embedded reinforcing ribs is placed on the top layer of fiber cloth, and finally the reinforcing rib top layer of fiber cloth is laid to form a preform.

[0025] Adhesive preparation and dispensing:

[0026] Curing and demolding:

[0027] After demolding, the material is polished to obtain a cap-shaped rib structure of composite sandwich structure with prefabricated parts.

[0028] Tapping: Tapping is performed at the designed location to form a bolted connection structure.

[0029] The beneficial effects of this invention are as follows: The embedded structure is designed within the cap-shaped reinforcing rib, and the embedded structure does not directly contact the sandwich panel structure. This effectively avoids stress concentration problems caused by the large differences in material properties between the components of the sandwich panel and the embedded structure, thus ensuring the strength of the sandwich panel structure and improving its service life. At the same time, the embedded structure is designed within the cap-shaped reinforcing rib, which indirectly increases the thickness of the embedded structure. This ensures the connection length between the embedded structure and bolts and other connecting parts. Compared with traditional metal embedded parts in sandwich panels, the thickness range of the embedded parts is wider, which improves the strength of the sandwich panel structure and the service life of the connection structure. This expands the application range of the embedded design and provides a new solution for the connection of special requirements, large-size doors, or other structures with surrounding reinforcement. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present invention.

[0031] Figure 2 This is a cross-sectional view of AA in this embodiment.

[0032] Figure 3 This is a cross-sectional view of BB in this embodiment.

[0033] In the figure: 10. Foam structure with embedded reinforcing ribs; 11. Embedded structure; 111. Composite material main component; 112. Metal embedded part; 113. Composite material base plate; 114. Interface bonding layer; 12. Reinforcing rib foam structure; 121. Interface bonding layer; 122. Hat-shaped reinforcing rib foam layer; 20. Sandwich panel structure; 201. Bottom skin layer; 202. Foam core layer; 203. Top skin layer; 301. Reinforcing rib skin layer; 40. Bolted connection structure. Detailed Implementation

[0034] To better understand the present invention, it will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] like Figures 1-3 The above describes a cap-shaped rib structure for a ship composite sandwich panel, specifically a cap-shaped rib structure for a ship composite sandwich structure with embedded parts, including a foam structure 10 with embedded reinforcing ribs, a reinforcing rib skin layer 301, and a bolt connection structure 40.

[0036] The foam structure 10 containing pre-embedded reinforcing ribs is disposed within the reinforcing rib skin layer 301;

[0037] The foam structure 10 with pre-embedded reinforcing ribs includes a pre-embedded structure 11 and a reinforcing rib foam structure 12. The pre-embedded structure 11 is disposed in the reinforcing rib foam structure 12 and is bonded and fixed.

[0038] The reinforcing foam structure 12 is fixed to the upper part of the sandwich panel structure 20;

[0039] The pre-embedded structure 11 is provided with a bolt connection structure 40, and the connector passes through the top of the reinforcing rib skin layer 301 and is connected to the bolt connection structure 40.

[0040] In this invention, the embedded structure 11 and the reinforcing foam structure 12 are bonded together to form a foam structure 10 containing embedded reinforcing ribs. The reinforcing foam structure is located within the reinforcing skin layer 301, forming a cap-shaped reinforcing rib structure. The bolt connection structure 40 is a bolt hole, and the connector is a bolt, which is threadedly connected to the bolt hole. The embedded structure is designed within the cap-shaped rib structure, combining the advantages of bolt specifications, embedded part thickness, and convenient tapping installation. Compared with metal embedded parts in traditional sandwich panels, the embedded part thickness range is wider.

[0041] Preferably, the reinforcing foam structure 12 includes a cap-shaped reinforcing foam layer 122, and the cap-shaped reinforcing foam layer 122 has an installation groove for installing the embedded structure 11. An interface adhesive layer 121 is formed between the embedded structure 11 and the cap-shaped reinforcing foam layer 122.

[0042] In this invention, the cross-section of the mounting groove is trapezoidal.

[0043] Preferably, the pre-embedded structure 11 includes a composite material main body 111 with a cavity at the bottom, a composite material base plate 113, and a metal pre-embedded part 112; the composite material main body 111 is placed in the mounting groove, and its outer side is bonded and fixed to the cap-shaped reinforcing foam layer 122; the bottom of the composite material main body 111 has a cavity, and the composite material base plate 113 and the metal pre-embedded part 112 are arranged sequentially from bottom to top in the cavity; the composite material base plate 113 is located at the top of the sandwich panel structure 20.

[0044] In this invention, the composite material base plate 113 is located at the bottom of the mounting groove, and the metal embedded part is placed on the composite material base plate 113; the top of the composite material main body 111 is flush with the cap-shaped reinforcing foam layers 122 on both sides, and an interface bonding layer 121 is formed between the side of the composite material main body 111 and the cap-shaped reinforcing foam layers 122 on both sides.

[0045] In this invention, both sides of the composite material base plate 113, the metal embedded part 112 and the composite material main body 111 are respectively in close contact with the cap-shaped reinforcing foam layer 122.

[0046] In this invention, the cavity is a trapezoidal cavity; the composite material base plate 113 and the metal embedded part 112 are disposed within the trapezoidal cavity, with both sides of each being tightly attached to the inner sidewall of the composite material main body 111; the composite material base plate 113, the metal embedded part 112, and the composite material main body 111 are bonded together with an adhesive, forming an adhesive interface layer 114 at the interface. The adhesive used is HW651 structural adhesive.

[0047] In this invention, the angle between the two sides of the cavity and the inner bottom is 30-70° (the specific angle can be adjusted according to the outer dimensions of the cap-shaped reinforcing rib to improve the bonding strength); the depth of the cavity is 20-60mm and the width is 40-100mm.

[0048] In this invention, both the composite material body 111 and the composite material base plate 113 are made of glass fiber reinforced resin laminate. Specifically, a glass fiber reinforced resin laminate of a set thickness is prepared using a vacuum integral molding process, and then processed according to the design dimensions to form the composite material body 111 and the composite material base plate 113. In the glass fiber reinforced resin laminate, the glass fiber is marine-grade high-strength glass fiber cloth, and the resin material is vinyl ester resin resistant to marine environments.

[0049] In this invention, the metal embedded part 112 is made of Q235, Q275 or Q345 steel, with Q345 steel being preferred.

[0050] Preferably, the sandwich panel structure 20 includes a bottom skin layer 201, a foam core layer 202, and a top skin layer 203 arranged sequentially from bottom to top; the bottom and top of the foam core layer 202 are respectively provided with grooves along the horizontal and vertical directions, and the grooves are filled with resin, which connects the foam core layer 202 to the top skin layer 203 or the bottom skin layer 201.

[0051] In this invention, both the foam core layer 202 and the cap-shaped reinforcing rib foam layer 122 use foam with a density of 80-200 kg / m³. 3The foam is high-strength PVC foam; the foam core layer 202 has a thickness of 10-40mm, and the cap-shaped reinforcing foam layer 122 has a thickness of 30-100mm. Grooves are formed on the upper and lower surfaces of the foam core layer 202 and the cap-shaped reinforcing foam 122 along the transverse and longitudinal directions, respectively. The groove spacing is 20mm, and the groove width is 2mm. These grooves serve as channels for resin flow during the vacuum molding process, and simultaneously, the cured resin increases interlayer shear strength. A 2mm diameter through-hole is provided at the intersection of the longitudinal and transverse grooves.

[0052] In this invention, the bottom skin layer 201, the top skin layer 203, and the reinforcing rib skin layer 301 are all made of marine high-strength glass fiber cloth or carbon fiber cloth, and the resin in the groove is made of vinyl ester resin that is resistant to marine environments.

[0053] According to the product molding process, a bottom skin layer 201, a foam core layer 202, a surface skin layer 203, a foam structure with embedded reinforcing ribs 10, and a reinforcing rib skin layer 301 are laid in the model. The resin is injected and molded using a vacuum molding process to complete the product preparation. After the product is cured, demolded, and trimmed, it is tapped and connected with bolts to form the structure 401.

[0054] This invention also proposes a method for manufacturing a cap-shaped rib structure for a ship composite sandwich panel, the method comprising the following steps:

[0055] 1. Preparation of composite material main body 111 and composite material base plate 113: Glass fiber reinforced resin laminate of a specific thickness is prepared by vacuum integral molding process, and then machined according to the design dimensions to form internal cavity structure 111 and composite material base plate 113.

[0056] 2. Metal Embedded Parts 112 Processing: Process the metal embedded parts according to the design dimensions and clean the surface of the metal embedded parts.

[0057] 3. Bonding of embedded structure 11: HW651 structural adhesive is used to bond and cure the metal embedded part 112 and the composite material base plate 113 to the composite material main body 111 to obtain the embedded structure 11.

[0058] 4. The embedded structure 11 is bonded to the cap-shaped reinforcing foam 122 to form a foam structure 10 containing the embedded reinforcing rib: HW651 structural adhesive is used to bond the embedded structure 11 to the cap-shaped reinforcing foam 122 to obtain the foam structure 10 containing the embedded reinforcing rib.

[0059] 5. Vacuum forming of the whole, specifically including the following steps:

[0060] (1) Mold preparation: Clean the mold and apply a release agent.

[0061] (2) Lay the bottom fiber cloth layer (bottom skin layer 201) in the mold according to the thickness requirements, place the foam core layer 202 on the laid fiber cloth layer, and lay the top fiber cloth layer (top skin layer 203) on the foam core layer 202; then place the foam structure 10 containing the pre-embedded reinforcing ribs on the top fiber cloth layer (top skin layer 203), and finally lay the reinforcing rib top fiber cloth layer (reinforcing rib skin layer 301) to form a preform.

[0062] (3) Laying vacuum auxiliary material and leak detection: Laying vacuum auxiliary material on the entire preform and checking the vacuum degree of the vacuum system to ensure that the vacuum degree meets the requirements; this is a conventional technology and will not be described in detail here.

[0063] (4) Preparation and injection of adhesive: Mix the resin evenly, turn on the vacuum pump, and inject the adhesive to fill the gaps of the preform.

[0064] (5) Curing and demolding: After the resin is poured, it is cured at room temperature. The surface hardness of the cured resin is tested with a hardness tester. At least two points have a Barcol hardness of 35 or higher before demolding.

[0065] (6) After demolding, the material is polished to obtain the cap-shaped rib structure of the composite sandwich structure with prefabricated parts.

[0066] (7) Tapping: Tap the threads at the designed location to form a bolted connection structure 40.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0068] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A cap-shaped rib structure for a ship composite sandwich panel, characterized in that, This includes a foam structure with embedded reinforcing ribs, a reinforcing rib skin layer, and a bolted connection structure; The foam structure containing pre-embedded reinforcing ribs is located within the reinforcing rib skin layer; The foam structure with pre-embedded reinforcing ribs includes a pre-embedded structure and a reinforcing rib foam structure. The pre-embedded structure is located inside the reinforcing rib foam structure and is bonded and fixed. The reinforcing foam structure is fixed to the upper part of the sandwich panel structure; The embedded structure is provided with a bolt connection structure, and the connector passes through the top of the reinforcing rib skin layer and is connected to the bolt connection structure. The reinforcing foam structure includes a cap-shaped reinforcing foam layer, and an installation groove for installing the embedded structure is provided in the cap-shaped reinforcing foam layer. The mounting groove has a trapezoidal cross-section; The embedded structure includes a composite material main body with a cavity at the bottom, a composite material base plate, and a metal embedded part; the composite material main body is placed in the mounting groove, and its outer side is bonded and fixed to the cap-shaped reinforcing foam layer; the bottom of the composite material main body has a cavity, and the composite material base plate and the metal embedded part are arranged sequentially from bottom to top in the cavity; the composite material base plate is located at the top of the sandwich panel structure.

2. The cap-shaped reinforcement structure of the ship composite sandwich panel as described in claim 1, characterized in that, The top of the composite material main body is flush with the cap-shaped reinforcing foam layers on both sides, and an interface bonding layer is formed between the side of the composite material main body and the cap-shaped reinforcing foam layers on both sides; the composite material base plate, the metal embedded part and both sides of the composite material main body are respectively in close contact with the cap-shaped reinforcing foam layers.

3. The cap-shaped reinforcement structure of the ship composite sandwich panel as described in claim 2, characterized in that, The angle between the two sides of the cavity and the inner bottom is 30~70°; the depth of the cavity is 20~60mm and the width is 40~100mm.

4. The cap-shaped reinforcement structure of the ship composite sandwich panel as described in claim 1, characterized in that, Both the composite material main body and the composite material base plate are made of glass fiber reinforced resin laminate.

5. The cap-shaped reinforcement structure of the ship composite sandwich panel as described in claim 2, characterized in that, The sandwich panel structure includes a bottom skin layer, a foam core layer, and a top skin layer arranged sequentially from bottom to top.

6. The cap-shaped reinforcement structure of the ship composite sandwich panel as described in claim 5, characterized in that, The upper and lower surfaces of the foam core layer and the cap-shaped reinforcing foam layer have grooves along the horizontal and vertical directions, respectively, and the grooves are filled with resin.

7. A method for manufacturing the cap-shaped rib structure of a ship composite sandwich panel as described in claim 5, characterized in that, The method includes the following steps: Fabrication of composite material body and composite material base plate: Metal embedded parts processing: The embedded structure is obtained by bonding and curing the metal embedded parts and the composite material base plate with the composite material body. The embedded structure is bonded to the cap-shaped reinforcing foam to form a foam structure containing the embedded reinforcing ribs: Vacuum forming, specifically includes the following steps: Mold preparation: According to the thickness requirements, lay the bottom layer of fiber cloth in the mold, place the foam core layer on the laid fiber cloth layer, and lay the top layer of fiber cloth on the foam core layer; then place the foam structure with embedded reinforcing ribs on the top layer of fiber cloth, and finally lay the reinforcing rib top layer of fiber cloth to form a preform. Adhesive preparation and dispensing: Curing and demolding: After demolding, the material is polished to obtain a cap-shaped rib structure of composite sandwich structure with prefabricated parts. Tapping: Tapping is performed at the designed location to form a bolted connection structure.

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