Analysis and Optimization of Composite Propeller Shaft for Automotive Applications

In the field of automotive engineering polymeric composites played vital role due to its outstanding properties such as high strength, low weight and high stiffness. The purpose of this research is to develop a single piece steel (Cr–Mo SCM440) drive shaft using computer aided modelling tool and finite element method was used for analysing static analysing and free vibration. These results were compared with the propeller shaft made by carbon and glass epoxy composites. ANSYS software is used for accomplish total deflection, natural frequency, and modal analyses. From this work it was noted that the propeller shaft made using carbon epoxy offered better results as compared with steel and glass epoxy composite propeller.


Introduction
In its most basic form, a composite material is a mix of two or more components. Advance

Materials and Methods
In this work three materials such as chromium molybdenum SCMM440 metallic material, carbon fibre reinforced epoxy composites and glass fibre epoxy composites were chosen for analysing the total deflection and natural frequencies in the propeller shaft [11,12]. Table 1 shows the chemical compositions and Table 2 shows the mechanical properties of SCMM 440 used for this research.

Polymer composite Material
Polymer matrix composites are the most often utilised advanced composites. These composites are prepared of a polymer and thin-diameter fibres (carbon, glass). They are most widely employed in the repair of aircraft structures because of their low cost, great strength, and easy production methods. Composite laminates are non-homogeneous, anisotropic material [13,14]. In this work carbon fibre and glass fibre reinforced polymer composites are used for comparing the metal propeller shaft. Table 3 shows the mechanical properties of carbon and glass fibre reinforced polymer composites used for this investigation.

Basic Composite Theory
In recent years, laminate composites have become increasingly popular in lightweight, highstrength constructions including ground transportation vehicles, aeroplanes, and space structures. However, composite materials have certain major drawbacks. The reaction to impact loading is the most important of these. When a foreign item collides with a structure, it creates an impact force [15][16][17].
In its simplest form, a composite material is one that is made up of at least two components that interact together to provide material qualities that are distinct from those of the individual constituents. In practise, most composites are made up of a bulk material and some form of reinforcement, which is added to boost the matrix's strength and stiffness. Typically, this reinforcement is in the form of fibres.

Reinforcing
Reinforcement adds strength and rigidity, as well as regulating the thermal expansion coefficient. It also aids in the attainment of directional qualities. Fibres, particles, or flakes can be used as reinforcements. The body and yoke sections are built of a fibre reinforced composite material that consists of a filament and a plastic that is attached to the filament [18]. In general, the fibre reinforcing effect of a fibre reinforced composite material decreases as the filaments that make up the composite material are bent more sharply. When the rotational speed is modest or the required characteristics, such as torsional strength, heat resistance, and moisture resistance, are low, the reinforced fibre can be glass fibre or aramid fibre alone, and the matrix resin can be a resin other than epoxy resin [19].

Modelling of propeller shaft using Ansys
The distinction of the material is based on mechanical qualities, however there is no clear border between the two. Polyester resins reinforced with low-strength glass fibers are commonly used to make reinforced plastics. The development of the material itself is frequently included into the manufacturing process when fabricating and molding polymer matrix composites into final items [20]. Examples of these processes are Lay-up by hand, molding in a vacuum, Lay-up using a spray gun, pultrusion and filament winding. Table 4 shows the fiber system codes used for modelling the propeller shaft in Ansys. The distinction of the material is based on mechanical qualities, however there is no clear border between the two. Polyester resins reinforced with low-strength glass fibers are commonly used to make reinforced plastics [21][22][23]. The development of the material itself is frequently included into the manufacturing process when fabricating and molding polymer matrix composites into final items. Examples of these processes are layup by hand, molding in a vacuum, layup using a spray gun, pultrusion and filament winding. In this work, automotive propeller shaft was made using ANSYS. Figure 1 shows the composite propeller shaft made in CAD. The following parameters such as mean radius, length, thickness of hallow shaft, thickness of fibre and angle of fibre orientation. Propeller shaft was idealised as shaft for modelling the shaft as cylindrical tube. Layers were defined from bottom to top. In this work general shell 98 element was selected for meshing purpose. The shape of the element was 'quadrilateral'. After creating FEM mesh of nodes and elements, nodes were merged. The geometric model was verified for geometric check, bad element check. The material used is glass fiber reinforced in epoxy matrix and carbon fiber reinforced in epoxy matrix. The pad command in the sketch-based features toolbar was used to pad this sketch by 22.5mm on both sides [24,25]. As indicated in Fig 1, tritangent fillet is now applied to both yokes. The contour between the yokes is created with the same tritangent fillet. Figure 2 shows the meshed view of composite propeller shaft used for this current investigation.  The propeller shaft is optimized using finite Element (FE) analysis with the help of ANSYS software. Figure 3 shows the total deflection obtained in the composite propeller shaft

Static Analysis
Static load was analysed for the three different materials such as steel (Cr-Mo SCM440), glass and carbon fibre composites of the composite propeller shaft. Table 4 explained the influence of wall thickness of the propeller shaft on angle of twist. From the figure it was noticed that comparing with steel and glass propeller shaft, carbon fibre offered good angle of twist. In carbon fibre offered more resistance before get fractured.

Figure 4
Angle of twist in composite propeller shaft

Weight reduction over buckling torque
In Ansys software mass calculation was done for the three different materials used in propeller shaft. Figure 5 it was observed that the propeller shaft made with carbon fibre composite weight is less as compared with other two. From the above discussion it was noted that the propeller shaft made with carbon fibre composite weight is less.