1Department of Mechanical Engineering, Velalar College of Engineering & Technology, Erode, ... unique properties of composite materials, automotive indus-.
Mechanics of Advanced Materials and Structures (2014) 21, 559–565 C Taylor & Francis Group, LLC Copyright ISSN: 1537-6494 print / 1537-6532 online DOI: 10.1080/15376494.2012.699599
Mathematical Modeling and Optimization of Mechanical Properties of Short Coir Fiber-Reinforced Vinyl Ester Composite Using Genetic Algorithm Method S. VELUMANI1, P. NAVANEETHA KRISHNAN2, and S. JAYABAL3 1
Department of Mechanical Engineering, Velalar College of Engineering & Technology, Erode, Tamilnadu, India Department of Mechanical Engineering, Kongu Engineering College, Perundurai, Tamilnadu, India 3 Department of Mechanical Engineering, A.C. College of Engineering and Technology, Karaikudi, Tamilnadu, India 2
Received 15 February 2011; accepted 10 November 2011.
The tensile, flexural, and impact properties of coir-fiber reinforced vinyl ester composites were evaluated. The short coir fibers with different proportions in fiber length and fiber content were used as reinforcements in polymer-based matrices. The mathematical models of tensile, flexural, and impact properties were developed using statistical packages and optimized using the genetic algorithm method to find the optimum fiber parameters for maximum value of mechanical properties. Keywords: composites, polymer matrix, mechanical properties, genetic algorithm
Nomenclature f1 = f2 = ts = fs = is = h = RM=
fiber length (mm) fiber content (wt%) tensile strength (MPa) flexural strength (MPa) impact strength (J/m) hours regression model
1. Introduction Over the last two decades, utilization of composites of polymer reinforced by natural fibers in many engineering fields has been on the rise. Reduced weight and increased performance properties, such as fatigue strength; stiffness; thermal resistance; and damping characteristics in aircraft, military, and space vehicle applications, had paved a path to the development of advanced engineering materials. However, these materials have not been utilized largely outside aerospace and allied fields due to mechanical properties and fast degradation. Looking into unique properties of composite materials, automotive industries and other consumer durable industries have started uti-
Address correspondence to S. Velumani, Department of Mechanical Engineering, Velalar College of Engineering &Technology, Erode, Tamilnadu 638012, India. E-mail: velumani2003@ gmail.com Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/umcm.
lizing these materials for manufacture of automobile bonnets, dash boards, bumpers, sports articles, leaf springs, etc. [1]. The optimum fiber parameters and their influence on the mechanical properties for coir-polyester resin were studied [2], and the results have shown that the fiber content in weight percentage is playing a major role than the fiber length on the improvement of tensile, flexural, and impact strength properties. The mechanical properties of natural fibers, such as banana, hemp, and sisal fibers with polystyrene resin, were evaluated [3]. The properties of composites made with natural fibers and polypropylene are extremely favorable and competitive to polypropylene with inorganic fillers. Mechanical properties were studied for sugar cane bagasse, elephant grass, wood, milk cartons, and recycled polypropylene [4]. Wood polymer composites based on natural fibers with HDPE resin were prepared in different ratios of 55:45, 50:50, 45:55, and 40:60 (wt%), respectively. Young’s modulus and flexural modulus decrease with an increase in fiber amount in the polymer [5]. Singh et al. [6] evaluated mechanical properties of pinus fiber after silane surface treatment. The use and mechanical properties of woven betel palm and kenaf fibers as a reinforcing phase in unsaturated polyester were evaluated [7]. Sisal and oil palm fibers were incorporated into a natural rubber matrix and the influence of fiber ratio on the cure and tensile properties of hybrid fiber-reinforced natural rubber composites were analyzed [8]. One of the applications of natural fiber composite is spur gear and gib joint fabricated with Roselle fiber/polyester [9]. Coir/epoxy composites exhibited average values for the tensile strength and flexural strength of 17.86 and 31.08 MPa, respectively [10]. The composites, with coir loading in a range of 9 to 15 wt% have a
