Modeling and Analysis of Drilling Induced Damages on Hybrid Composites

Background/Objectives: To investigate the damages that occurs during drilling on newly prepared hybrid composites. Methods/Analysis: Composites have been prepared by using randomly oriented steel wool and woven jute as reinforcements and polyester as the matrix resin. Drilling experiments have been carried out on the developed composite by adopting Box-Behnken methodology. Speed, feed rate, point angle and tool diameter are taken as the input factors and the damage at entrance and exit surfaces have been measured as output responses. Findings: The output factors have been analyzed and optimized to yield a set of optimum conditions on the basis of desirability approach. The results showed that speed, feed rate and tool angle have significant influence on the entrance and exit damages but tool diameter does not have any influence. A speed of 500 rpm-970 rpm, a constant feed of 0.1 mm/rev, a tool angle of 900-1200, and selection of 8 mm and 10 mm as tool diameter are found to be the optimum input conditions for drilling. Confirmatory experiments have been conducted for the set of optimum conditions and the responses have been measured. The developed model is validated by an error analysis between the model and confirmatory runs. The observed errors between the model and confirmatory runs are meagre and hence the optimization using Box-Behnken design is satisfactory. Novelty/Improvement: Machining associated failures must be resolved in order to improve the productivity. This research made an attempt to optimize drilling associated damages on new composites made by using metal and natural fibers as reinforcement.