• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.49-52
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• 1999

Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and specific strength of composite materials. In this work, one-piece propeller shafts composed of carbon/epoxy composite and glass/epoxy one were designed and manufactured for a rear wheel drive automobile, which uses generally a steel two-piece propeller shaft. From the tests of the composite propeller shafts, it was found that the propeller shafts satisfied requirements of static torque transmission capability, torsional buckling capability and the first natural bending frequency and had 40% weight saving effect compared with steel propeller shaft.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.22-26
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• 2002

The goal of this study is to replace the current forward 2-piece propeller shaft of 8 ton large truck made of steel with 1-piece composite propeller shaft. A low cost Glass/Epoxy composite propeller shafts were successfully developed, which satisfy requirements such as the capacity of static torque transfer, fatigue strength and bending natural frequency. Devising secure joining method of a composite tube and metal yoke was the most critical issue in successful development of a high torque composite propeller shaft. In this study, joining method using thermal interference fit was adopted for composite to metal joint. Optimum conditions of heating temperature and interference level of thermal interference fit were determined from thermal stress analysis using 3D finite element method. Static torsion test, fatigue test, RPM and balance test were performed to verify the design.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.149-153
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• 2000

Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and specific strength of composite materials. In this work, one-piece propeller shafts composed of carbonfepoxy and glass/epoxy composites were designed and manufactured for a rear wheel drive automobile satisfying three design specifications, such as static torque transmission capability, torsional buckling and the fundamental natural bending frequency. Single lap adhesively bonded joint was employed to join the composite shaft and the aluminum yoke. For the optimal adhesive joining of the composite propeller shaft to the aluminum yoke, the torque transmission capability of the adhesively bonded composite shaft was calculated with respect to bonding length and yoke thickness by finite element method and compared with the experimental result. Then an optimal design method was proposed based on the failure model which incorporated the nonlinear mechanical behavior of aluminum yoke and epoxy adhesive. From the experiments and FEM analyses, it was found that the static torque transmission capability of composite propeller shaft was maximum at the critical yoke thickness, and it saturated beyond the critical length. Also, it was found that the one-piece composite propeller shaft had 40% weight saving effect compared with a two-piece steel propeller shaft.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.151-159
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• 2003

The front 2 pieces of the 3-piece steel propeller shaft installed on a 8.5-ton truck were redesigned with a 1 -piece composite propeller shaft with steel yokes and spline parts to get the reduction of weight and the improvement of NVH characteristics. Based on the analysis of bending vibration, strength and cure-induced residual stresses of the composite propeller shaft, proper composite materials and stacking sequences were selected. The composite propeller shaft requires a reliable joining method between the shaft and steel end parts through a steel connector. From 3-D contact stress analyses of the laminated composite shaft with bolted Joints, the 3-row mechanical joint which satisfies the torque transmission capability has been designed. Several full-scale composite shafts were fabricated and tested to verify the design analyses. The design requirements are shown to be satisfied. With the newly designed composite shaft, the weight reduction more than 50% and improvements in NVH characteristics have been achieved.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.203-217
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• 2009

The researches on the development of composite material propeller with outstanding damping effects have been actively attempted for the reduction of radiation noise of underwater vehicle propeller. Composite material suitable for the flexible propeller has the following advantages, such as high specific strength and specific stiffness, low thermal expansion coefficient, high resistance against environmental deterioration, low possibility of corrosion due to cavitation, nonoccurrence of rapid fracture due to fatigue, easy molding of complicated shape, easy repair maintenance and low production costs, etc. For the confirmation of optimal fiber array structures of composite material for the production of the flexible propeller blades, in this study, mechanical characteristics of its specimens according to materials were obtained and structural characteristics of propeller blade were also examined according to materials and stacking fiber arrays.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.2
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• pp.61-69
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• 2020

Due to its flexibility of the composite propeller blade, it is necessary to design a shape capable of generating a desired load at a design point in consideration of the shape change of the propeller. In order to design it, we need to evaluate not only the hydrodynamic force around it, but also its structural response of flexible propeller according to its deformation. So, it is necessary to develop a design tool to predict the hydroelastic performance of a flexible propeller with deformation considering fluid-structure interaction and special operating conditions. Finally a design optimization tool for flexible propellermade of CFRP is required. In this study, a design methodology of the specific flexible composite propeller is suggested, considering fluid-structural interaction analysis of the specific flexible propeller.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.11-17
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• 2012

The one way fluid structure interaction analysis on advanced propeller blade for next generation turboprop aircraft. HS1 airfoil series are selected as a advanced propeller blade airfoil. Adkins method is used for aerodynamic design and performance analysis with respect to the design point. Adkins method is based on the vortex-blade element theory which design the propeller to satisfy the condition for minimum energy loss. propeller geometry is generated by varying chord length and pitch angle at design point. Blade sweep is designed based on the design mach number and target propulsion efficiency. The aerodynamic characteristics of the designed Advanced propeller were verified by CFD(Computational Fluid Dynamic) and showed the enhanced performance than the conventional propeller. The skin-foam sandwich structural type is adopted for blade. The high stiffness, strength carbon/epoxy composite material is used for the skin and PMI(Polymethacrylimide) is used for the foam. Aerodynamic load is calculated by computational fluid dynamics. Linear static stress analysis is performed by finite element analysis code MSC.NASTRAN in order to investigate the structural safety. The result of structural analysis showed that the design has sufficient structural safety. It was concluded that structural safety assessment should incorporate the off-design points.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.279-285
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• 2013

The feasibility of substituting a composite mold for an aluminum mold in the fabrication of a small ship propeller was investigated. A small three-blade aluminum propeller was used as a plug for manufacturing the composite mold. A GRPG composite mold and propeller were made from an unsaturated polyester resin, Epovia gelcoat, and woven and mat glass fibers using the compression and vacuum method at room temperature. The hardness and surface roughness and the strength and deformation of the compression and suction molds were experimentally determined. The results were compared with the ISO 484/2 standard and some aluminum alloy materials. The results showed that the deformation of the mold satisfied the tolerance of the thickness of the blade. Some characteristics of the GRPG composite mold were better than those of the aluminum alloy mold (surface smoothness, weight, performance, and cost), and some characteristics were similar (detachment ability and life-cycle). Therefore, the composite mold is considered suitable for the fabrication of a small composite ship propeller.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.3
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• pp.57-68
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.253-258
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.