섬유강화 복합소재에 의한 경량의 선박용 동력전달축 개발

Abstract

High performance composites are being used increasingly for engineering applications such as space vehicles, aircrafts, road transportations, fishing-rods, golf-club shafts and yachts because of their two major advantages, namely, the higher specific strength and specific modulus. From these viewpoint, the advent of advanced fiber reinforced composites has been called the biggest technological revolution.

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over rotating mandrel. The filament winding method is affected by several parameters such as pot life of process time, viscosity of resin, filament winding temperature, curing condition, etc.

It is known that the composite material shafts using on small boats have various advantages comparing to forged steel shafts, for examples

3.75 mm), it was found that the tensile strength becomes a constant value. This shows that the effect of fiber is bigger than effect of matrix. It was found that the elongation according to the number of layers has little change in the layers of 5 or more. The result of torsional static test for the hollow shaft composites was measured 2316 N-m at 0.505 radian (28.9°) , and the fracture happened in adhesion department with slip in higher stress than in calculated torsional stress. Adhesion strength by the adhesive was about 450 N-m at 0.046 radian (2.6°) .

It is found that the hollow shaft composites had 76% weight saving effect comparing with a traditional metal shaft.

3.0 mm). Also in the case of more than 5 layers (thickness

1.5 mm) to 4 layers (thickness

high specific strength, high fatigue strength, high corrosion resistance, etc.

The purpose of this study is to analyze and design the stress of hollow shaft composites, and to evaluate the characteristics of hollow shaft composites which is wound by filament winding method.

The analysis of the stresses and strains in the hollow shaft composites made by filament winding method is presented in this paper. Classical laminated plate theory was applied on the patch cut from the hollow shaft composites. The classical laminated plate theory was used for analyzing the stress, and for structure design. The diameter and thickness of composite shaft were calculated by this theory, and were considered the criterion of class rule in design.

It is verified that the hollow shaft composites of diameter 40 mm is the most optimum when the ratio of diameter is 0.4 and winding angle is 45°. It is also proven that the shear strain does not change seriously between 30°and 60° of winding angles. It is dangerous when the winding angle is over 75°because the values of shear strain and stress produced on the shaft are too high, and so it must be avoided to wind the filament by the angle over 75°.

The performance test of hollow shaft composites made by filament winding method is presented in this paper.

The results showed that the fiber content was 60.1 % and the resultant void content was 1.1 %. The fiber content was proper and the void content was very low.

The tensile tests were performed to verify strength of composite shafts according to the number of layers, and also the torsional tests were performed to verify strength of composite shafts and adhesive joints.

The results of tensile tests according to the number of layers were changed greatly from 2 layers (thickness