CN102230489A - T-shaped connection structure of composite material laminboard - Google Patents

Abstract

The invention provides a "T" type connection structure of a composite material sandwich panel. Including connecting bottom plate, honeycomb sandwich panel and T-shaped reinforcing block, the honeycomb sandwich panel has a groove with the same shape as the upper web of the T-shaped reinforcing block, and the upper web of the T-shaped reinforcing block is inserted into the groove , the wing rafters of the T-shaped reinforcing block are glued to the connecting bottom plate, and two corrugated connectors are also included. The two corrugated connectors are located on both sides of the honeycomb sandwich panel. The bolts are tightly connected between them, and the wave connector and the connecting bottom plate are connected by glue and screws. The invention has the advantages of high bending rigidity; a larger space is formed between two corrugated plates, which brings convenience to some pipeline laying and subsequent maintenance; it can effectively relieve stress concentration at joints, improve structural efficiency, and enhance bearing capacity. Suitable for mechanical connections between composite sandwich panels and other structures in large structures.

Description

A composite material sandwich panel "T" connection structure

technical field

The invention relates to a connection structure of composite material sandwich panels, and is especially suitable for the mechanical connection between composite material sandwich panels and other structures in large-scale structures.

Background technique

Compared with general engineering materials, fiber-reinforced resin matrix composites have anisotropy in strength and stiffness, lower interlaminar strength and lower ductility, so the load redistribution ability in the stress or strain concentration area of the joint is weaker. According to some data, the mass of joints accounts for about 20%-30% of the mass of the entire structure, and most of the damage (60%-80%) of composite structures also occurs at the joints. Therefore, the connection problem is one of the key technologies that affect the performance of composite materials. Solving the connection problem of composite material structures is of great significance for reducing structural quality and improving structural performance. At present, the composite material sandwich structure is widely used in aviation, aerospace, and shipbuilding industries due to its good topology optimization. The connection methods between the composite material sandwich panel and other structures include adhesive bonding, mechanical connection and hybrid connection; Lap joints, support connections, etc., a typical "T" type support connection load-bearing member is designed to connect the ship's airtight cabin and hull, this "T" type connection can ensure the integrity and airtightness of the structure, and provide Orthogonal support connection shows good advantages, but its topology optimization is not high, the bending resistance is insufficient, and failure modes such as slanted disbond will occur when subjected to bending moment.

Traditional bonded composite material "T" joints are usually widely used as load-bearing structures of composite ships, such as: waterproof and airtight compartments of ships. Although the bonded connection has a strong shear capacity, it has poor resistance to peeling. When the "T" joint of the bonded composite material is subjected to the normal force and the peeling force, due to the weak load-bearing capacity of the adhesive, the load-bearing capacity of these two types is insufficient, and debonding and delamination of the laminate are prone to occur, which ultimately affects Airtightness and load-bearing characteristics, at the same time, because the adhesive damage is not easy to be found in time, it is prone to relatively sudden catastrophic damage, causing heavy losses.

Due to the advantages of high reliability and easy repeated disassembly and assembly, mechanical connection has gradually become the most commonly used connection method. As composite materials are more and more widely used in various fields, the connection of composite materials also has various forms. At this stage, the mechanical connection of composite materials can be mainly divided into riveting and bolt connection. In practical applications, different mechanical connection methods can be selected according to different load conditions.

Contents of the invention

The object of the present invention is to provide a composite material sandwich panel "T" connection structure with good bending resistance and high space utilization.

The object of the present invention is achieved in this way: including connecting base plate, honeycomb sandwich panel and T-shaped reinforcing block, the honeycomb sandwich panel has the same groove as the top shape of the web of the T-shaped reinforcing block, and the web of the T-shaped reinforcing block The top of the board is inserted into the groove, and the wing rafters of the T-shaped reinforcing block are glued to the connecting bottom plate, and two corrugated connectors are also included. The two corrugated connectors are located on both sides of the honeycomb sandwich panel. The corrugated connectors, T The reinforced block and the honeycomb sandwich panel are tightly connected by bolts, and the corrugated connector and the connecting bottom plate are connected by glue and screws.

The present invention may also include:

1. The upper end of the web of the T-shaped reinforcing block is stepped, and the lower end is concave on both sides.

2. The T-shaped connector is molded with 40% short glass fiber and epoxy resin at one time.

3. The corrugated connector is pultruded with three-dimensional glass fiber braid and epoxy resin.

4. The connection bottom plate is formed by hot pressing of glass fiber and epoxy resin.

The purpose of the present invention is to solve some shortcomings of the traditional "T" connection, and to invent a "T" connection form and method between the composite material sandwich panel and the connecting bottom plate, which is applied to the connection between orthogonal structures.

The characteristics of the present invention are mainly reflected in: firstly, the corrugated connector support is used as the main load-bearing member, and a large bending moment is formed between the two corrugated connectors. Under the same conditions, the bending rigidity of the traditional T-shaped connection is improved. More than 1 times, using two corrugated connectors as the main load-bearing part also has the advantages of clear load path and simple calculation; secondly, a larger space is formed between the two corrugated plates, which brings more trouble for some pipeline laying and subsequent maintenance. It is convenient; thirdly, the stepped connection between the sandwich panel and the T-shaped reinforcing block can effectively relieve the stress concentration at the joint and improve the structural efficiency. Finally, the adoption of sandwich panels greatly reduces structural mass without compromising structural performance. The mixed connection of bolts, screws and glue joints greatly enhances the connection performance of the joints and enhances the bearing capacity.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic diagram of the assembly structure of the present invention.

Detailed ways

The present invention is described in more detail below in conjunction with accompanying drawing example:

1 and 2, the present invention mainly includes connecting bottom plate 7, honeycomb sandwich panel 1 and T-shaped reinforcing block 8, the honeycomb sandwich panel has the same groove as the top shape of the web of the T-shaped reinforcing block, and the T-shaped reinforcing block The upper end of the web plate of the block is inserted into the groove, and the wing rafter of the T-shaped reinforcing block is glued to the connecting bottom plate, and also includes two corrugated connectors 5, the two corrugated connectors are located on both sides of the honeycomb sandwich panel, and the corrugated The connecting piece, the T-shaped reinforcing block and the honeycomb sandwich panel are tightly connected by a bolt connection structure composed of bolts, washers and nuts 2, 3, 4, and the wave-shaped connecting piece and the connecting bottom plate are connected by glue and screw 6 . The upper end of the web of the T-shaped reinforcing block is stepped, and the lower end is concave on both sides.

The production process of the present invention is as follows: the cut honeycomb composite material is bonded with the skin to form the honeycomb sandwich panel 1, and then the honeycomb sandwich panel 1 is reinforced with a T-shaped molding with 40% short glass fiber and epoxy resin. Block 8 is glued together, and then bolts, washers, nuts 2, 3, 4 are used to connect the corrugated connector 5, and the honeycomb sandwich panel 1 is connected to the T-shaped reinforcement block, wherein the corrugated connector 5 is a three-dimensional glass fiber braid and epoxy Resin pultrusion. Finally, glue the connected corrugated connector 5) T-shaped reinforcing block 8 to the base plate 7, and then use the screw 6 to fix the corrugated connector 5 again, and the base plate 7 is formed by thermocompression of glass fiber and epoxy resin. The honeycomb sandwich panel and the upper web of the T-shaped reinforcement block are connected in a stepped shape, and the double-sided skin is used to realize the glue connection. The lower end of the T-shaped reinforcement block is concave on both sides, in the shape of a "cup". glued. There are two wave-shaped connectors on both sides of the connection, the wave-shaped connectors are used as the main load-bearing part and the auxiliary load-bearing part of the T-shaped reinforcement block, the wave-shaped connector, the T-shaped reinforcement block, and the skin are tightly connected by bolts, and the wave-shaped connection The glue-screw hybrid connection between the parts and the bottom plate connector. The T-shaped joint connected by bolts and screws has enhanced ability to withstand normal loads, and there will be no peeling and delamination. Bolts and screws can withstand high normal loads, and are resistant to impact and fatigue. Make up for the lack of purely mechanical connections and increase shear resistance.

Claims (9)

1. A composite material sandwich panel "T" type connection structure, comprising a connection base plate, a honeycomb sandwich panel and a T-shaped reinforcement block, characterized in that: the honeycomb sandwich panel has a web top shape with the T-type reinforcement block In the same groove, the upper end of the web of the T-shaped reinforcing block is inserted into the groove, the wing rafter of the T-shaped reinforcing block is glued to the connecting bottom plate, and two wave-shaped connecting pieces are included, and the two wave-shaped connecting pieces are located in the honeycomb clip On both sides of the core plate, the corrugated connectors, T-shaped reinforcing blocks and honeycomb sandwich panels are tightly connected by bolts, and the corrugated connectors and the connecting bottom plate are connected by glue and screws. 2. A "T"-shaped connection structure for composite sandwich panels according to claim 1, characterized in that: the upper end of the web of the T-shaped reinforcing block is stepped, and the lower end is concave on both sides. 3. A composite material sandwich panel "T"-shaped connection structure according to claim 1 or 2, characterized in that: the T-shaped connection piece is formed by one-time compression molding of 40% short glass fibers and epoxy resin. 4. A composite material sandwich panel "T" connection structure according to claim 1 or 2, characterized in that: the corrugated connector is formed by pultrusion of three-dimensional glass fiber braid and epoxy resin. 5. A composite material sandwich panel "T"-shaped connection structure according to claim 3, characterized in that: the corrugated connector is formed by pultrusion of three-dimensional glass fiber braid and epoxy resin. 6. A composite material sandwich panel "T" connection structure according to claim 1 or 2, characterized in that: the connection bottom plate is molded by hot pressing of glass fiber and epoxy resin. 7. A composite material sandwich panel "T" connection structure according to claim 3, characterized in that: the connection bottom plate is molded by hot pressing of glass fiber and epoxy resin. 8. A composite material sandwich panel "T" connection structure according to claim 4, characterized in that: the connection bottom plate is molded by hot pressing of glass fiber and epoxy resin. 9. A composite material sandwich panel "T" connection structure according to claim 5, characterized in that: the connection bottom plate is molded by hot pressing of glass fiber and epoxy resin.

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