Experimental Investigation and Statistical Modelling of Cutting Force and Torque During Rotary Ultrasonic Drilling of Polyetherimide Composite

• Published in: Strength of materials 2023-03, Vol.55 (2), p.355-370
• Main Authors: Shard, A., Garg, M. P., Gupta, V.
• Format: Article
• Language: English
• Subjects: Abrasive cutting; Carbon fibers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Composite materials industry; Cutting force; Cutting parameters; Drill bits; Drilling; Drilling and boring; Feed rate; Fiber composites; Grit; Laminated materials; Machining; Materials Science; Polyetherimide; Polyetherimides; Process parameters; Solid Mechanics; Statistical models; Torque; Ultrasonic vibration; Variance analysis
• ISSN: 0039-2316; 1573-9325
• DOI: 10.1007/s11223-023-00530-7

Drilling is one of the common machining operations performed on the carbon fiber composite. For making a hole in the carbon fiber composite, normal drilling method is widely used in the industry. Carbon fiber composites have layered structure and during the drilling significant amount of cutting forces and torque are generated. If the level of cutting forces and torque is high then it may cause delamination of the layers of fabricated composite, hole quality can be damaged, drill bit can be jammed/break during drilling operations. To overcome, the aforesaid problems the rotary ultrasonic drilling method was used to reduce the cutting forces and torques exerted on the composite during the drilling of polyetherimide composite. The standard laying off and compression methodology were used to fabricate the polyetherimide composite. The effect of the machining parameters of ultrasonic power, rotational speed, feed rate and abrasive grit size on the cutting force and torque has been studied and then subsequently analyzed by analysis of variance. Statistical models were also developed and validated to minimize the cutting forces and torque during the drilling of polyetherimide composite. It has been observed that cutting force and torque are highly influenced by abrasive grit size, feed rate, rotational speed, and ultrasonic vibrations. Experiments were also performed to compare the rotary ultrasonic drilling with and without vibrations with a standard conventional drilling method. It has been observed that cutting forces can be reduced to 50 % using the rotary ultrasonic drilling in comparison to conventional drilling method.