D.Dinesh, F.Anand Raju / International Journal Of Engineering Research And Applications (IJERA) ISSN: 2248-9622 Www.Ijera.Com Vol. 2, Issue4, July-August 2012, Pp.1874-1880 1874 | P a g e Optimum Design And Analysis Of A Composite Drive Shaft For An Automobile By Using Genetic Algorithm And Ansys D.DINESH*, F.ANAND RAJU** *Department of Mechanical Engineering, SIETK College, Puttur, Chittoor Dist, AndhraPradesh, INDIA. ** Department of Mechanical Engineering, SIETK College, Puttur, Chittoor Dist, Andhra Pradesh, INDIA. Abstract: Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and strength of composite materials. This work deals with the replacement of conventional two-piece steel drive shafts with a single-piece e-glass/epoxy, high strength carbon/epoxy and high modulus carbon/epoxy composite drive shaft for an automotive application. The design parameters were optimized with the objective of minimizing the weight of composite drive shaft. The design optimization also showed significant potential improvement in the performance of drive shaft. Keywords:-Torque transmission, Torsional buckling capacities, Fundamentallateral Natural frequency, Bernoulli Euler theory, Timoshenko beam theory, Static analysis, Modal analysis, Buckling analysis, Ansys. 1. INTRODUCTION Advancedcomposite materials can be defined as combination of materials appropriately arranged using reinforcing fibers, carefully chosen matrixes, and some times auxiliary materials like adhesive core and other inserts. These combinations after proper manipulation and processing result in finished structure/item with synergistic properties i.e. properties achieved after fabrication cannot be obtained by individual components acting alone. The ACMs can be classified in different categories on the basis of micro structures, multiphases, reinforcements, manner of packing fibers layered compositions, method of composition, matrix system processing methods etc. Basic components of ACMs are (i) Reinforcement (fibers) (ii) Matrix (iii) Honey comb core/adhesives ( for sand witched structures ). The great variety of fibers materials in various forms, shapes and sizes have been recently developed for use in ACMs and in the construction industries. Steel, glass, carbon, Aramid (kevlar), boron, silicon carbide, silicon nitrates, alumina fibers are some of the commonly used high performance reinforcement fibers in ACMs. The reinforcements may be called by different names according to sizes such as Whisker ( < 0.025 mm ), fiber ( 0.025 – 0.8 mm ), Wire ( 0.8 – 6.4 mm ), rod ( 6.4 – 50 mm ) and bar ( > 50 mm ). In general the continuous filamentary type reinforcement is important from structural application point of view. It is the reinforcement which is primarily responsible for the mechanical properties of ACMs. Usually all the reinforcements (fibers) are stronger in tension than steel, but weak in shear ( i.e. brittle ) requiring the filler material (Matrix) relatively strong in shear which will protect reinforcement against abrasion or environmental corrosion. Matrix also helps in distributing the load from reinforcement, absorbing energy, reducing stress concentration and preventing cracks propagation. Thermosetting and thermo plastic types of organic polymers are used as Matrix ( e.g. epoxide, phenolic, polyamide resins etc.). Some of the important fibers used as reinforcement in ACMs along with their characteristic properties are discussed briefly. Glass fiber properties. Property E-glass R-glass D-glass S-glass Density (g/cm 3 ) 2.60 2.55 2.16 2.49 Tensile strength (Mpa) 3400 4400 2500 4580 Tensile modulus (Gpa) 73 86 55 86.93 Elongation at break (%) 4.5 5.2 4.5 5.4 Filament diameter 3-14 3-14 3-14 – Properties of Aramid fibers property Polyester Monex Kevlar29 Kevlar49 Teflon Density 9/cm 3 1.38 1.38 1.44 1.45 2.15 Tensile Strength(MPa) 900 670 2700 3500 - Tensile Modulus(GPa) 18 60 135 133 – Elongation at break % 10-15 20-30 4 2.5 20-30 Filament diameter 10-12 – – – 20