Application of marine composite materials (carbon fiber/fiberglass/aramid)

Marine composite materials, especially those used in hull structures, are mainly polymer-based composite materials.

According to the different load-bearing parts, it can be divided into: main load-bearing structure, secondary load-bearing structure, non-load-bearing structure,

The superiority of performance is mainly reflected in: light weight and high strength, which can effectively improve the reserve buoyancy of the hull; the structure and function are integrated, and the performance can be designed under the condition of satisfying the structural load, usually with acoustics, radar, vibration reduction, protection, low magnetic, etc.

At present, carbon fiber composite materials have been widely used in aerospace, sports and leisure, automotive industry, environmental energy, civil engineering and other fields, and its application range is almost everywhere

In addition, the most important reason to use carbon fiber is that the material can improve the speed and fuel economy of ships by reducing weight

The application of carbon fiber and its composite materials in yachts, through the use of CFRP in the superstructure and deck equipment, can further reduce weight and improve the stability of the ship; carbon fiber drive shafts can also reduce weight and reduce vibration; carbon fiber in propeller blades There are also potential wide-ranging applications

As early as the 1940s, the US Navy used composite materials to build small ships, which opened a new chapter in ship construction.

As a major country in the manufacture of composite ships in Asia, Japan began to build FRP ships as early as 1953.

Carbon fiber has two types of high strength and high modulus.

Aramid fiber has the characteristics of high specific strength, high toughness, impact resistance and ballistic resistance, and is used for boat components with high requirements for tensile, active load and bulletproof
.
Due to the low compressive bending strength, it is not suitable for the manufacture of high-compression and high-bending hulls, and is only suitable for ships with strict weight limits
.

When considering the cost in the manufacture of boats, under the premise of meeting the design requirements, a design method using hybrid fiber composite materials has emerged
.
The mixed use of a variety of fiber-reinforced materials overcomes some of the shortcomings of single-fiber composite materials, improves physical and mechanical properties, and further improves the designability of materials
.
The two-dimensional and three-dimensional fabrics formed by reinforcing materials can be manufactured according to the design needs to meet the strength, intra-layer and inter-layer performance of ships, and further achieve the requirements of light weight and high strength for ships

Due to the light weight of composite materials, the US Navy plans to use glass-reinforced phenolic composite materials in the power compartment, including cylinders, cylinder heads, oil pans, cam covers, support rollers, speed control sprockets, and water pumps, oil pumps, and pulleys of marine diesel engines.
etc.

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Some mechanical elements of surface ships can also be made of composite materials, and in the trend to reduce the weight of the hull, the weight reduction of the power transmission components of the propulsion system is also on the agenda
.
Typically, on high-speed boats where 2 or 4 high-speed diesel engines drive the waterjet through a reduction gearbox, the distance between the diesel engine and the gearbox, or between the gearbox and the waterjet, is shortened
.
Especially in the narrow space of the catamaran, 4 diesel engines are required to be arranged in a staggered manner, and the power generated by the front diesel engine must be transmitted through the rear diesel engine
.
Therefore, this requires a transmission with the lightest weight and the fewest components
.
The use of the drive shaft made of carbon fiber tube material can easily achieve the purpose of reducing the weight of the transmission components
.

The main advantages of CFRP drive shafts include: significantly reduce the weight of the drive shaft; high critical speed, usually do not need to arrange bearings on long shafting, reduce the number of bearings, reduce costs, reduce shafting, reduce parts, Save the cost of bearing supports and reduce weight; corrosion resistance, low magnetic signal, electrical signal, anti-wear, can reduce the noise in structure and air up to 520dB
.