Okoye Samuel Lotanna and Ubani Nelson Obinna/ Elixir Mech. Engg. 69 (2014) 23228-23238 23228 Introduction Ukam plant fiber has been used as cordage crop to produce twine, rope, sack cloth, building material, absorbent and animal feeds. Ukam plant fiber is an example of natural plant fiber sourced at Nsukka area in Enugu state of Nigeria. Natural fibers have recently become attractive to researchers, engineers and scientists as an alternative reinforcement for fiber reinforced polymer (FRP) composites. Due to their low cost, fairly good mechanical properties, high specific strength, non-abrasive, eco-friendly and biodegradability characteristics, they are exploited as replacement for the conventional fiber, such as glass, aramid and carbon[1]. Cashew nut shell liquid (CNSL) is one of the examples of the class of thermosetting natural resin referred to as bio-resins. This study focused on determination of the optimal setting of control factors affecting impact strength response of ukam plant fiber reinforced CNSL biocomposite. Composites are termed bio composites if either the reinforcement or the matrix phase is from natural sources. Both ukam plant fiber and Cashew nut shell liquid used in this research are from natural sources. Literature/background of study Studies carried out with traditional experimental method of utilizing one-factor-at-a-time method has inherent inabilities to determine the effects that are caused by several factors acting in combination, requires more runs of experiments for the same precision in effect simulation, can miss out optimal settings of factors and cannot estimate interactions. [2, 3, 4, 5]. That is the case with research done so far using Ukam plant fiber as reinforcement. Apart from the fact that only few literatures are available on the properties of the fiber, the ones studied were only carried out with one-factor-at-time method. Okpanachi and Ogakwu [6] investigated the effects of fiber surface treatment on the mechanical properties of Ukam Fiber reinforced polyester composites. Saline, alkaline and acidic treatments were used to perform the surface modification of Ukam fiber. Twelve samples were produced and tensile, compressive and bending tests were conducted to determine the properties of the specimen based on untreated, saline, alkaline and acid treatments conditions. Results obtained showed that surface treatment especially sodium hydroxide treatment gave improvements on properties up to 79%. A conclusion was reached by stating that surface treatments have significant impact on the mechanical properties of Ukam Fibers. Ugoamadi [7] studied the factors that improve the impact responses of Ukam plant fiber reinforced composite. One-factor-at-a- time method of experimental design was utilized to study the effect of fiber conditions, Application of additives, fiber length, fiber orientation and fiber volume fraction on impact response of Ukam plant reinforced polymer composite. Samples were also produced Optimal process parameters settings affecting the impact strength response of biocomposite materials Okoye Samuel Lotanna 1 and Ubani Nelson Obinna 2 1 Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria. 2 Department of Mechanical Engineering, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria. ABSTRACT This paper utilized Taguchi robust design of experiment to obtain the optimum response and optimum setting of control factors affecting the impact strength response of ukam plant fiber reinforced CNSL biocomposite. Fiber Orientation (A), Fiber volume fraction (B) and Aspect ratio(C) are the considered process parameters used in the study. Charpy Impact test was carried out considering Standard L9 orthogonal array for the nine experimental runs and the optimization was done based on a larger is better Signal Noise ratio. Fiber volume fraction had the most significant effect on impact strength response evaluated. The optimum impact strength was captured as 11.12963KJ/m 2 . © 2014 Elixir All rights reserved. Elixir Mech. Engg. 69 (2014) 23228-23238 Mechanical Engineering Available online at www.elixirpublishers.com (Elixir International Journal) ARTICLE INFO Article history: Received: 17 September 2013; Received in revised form: 29 March 2014; Accepted: 14 April 2014; Keywords Taguchi robust design, Impact strength, Biocomposite, Charpy impact test. Tele: E-mail addresses: grantnelson2007@yahoo.com © 2014 Elixir All rights reserved