An investigation of the effects of step drill geometry on drilling induced delamination and burr of Ti/CFRP stacks

2020 ◽  
Vol 235 ◽  
pp. 111786 ◽  
Author(s):  
Zhen-yuan Jia ◽  
Chong Zhang ◽  
Fu-ji Wang ◽  
Rao Fu ◽  
Chen Chen
Keyword(s):  
Step Drill

Mathematical Models and Grinding Research for Step Drill

2004 ◽  
Vol 259-260 ◽  
pp. 411-414 ◽  
Author(s):  
S.J. Hu ◽  
Zhi Xiong Zhou ◽  
T.Y. Long
Keyword(s):  
Mathematical Models ◽  
Step Drill

scholarly journals Precise Design of Drill Structure Based on Cutting Force Distribution Alone Cutting Edge in CFRP Drilling

2021 ◽  
Author(s):  
Xin-Yi Qiu ◽  
Peng-Nan Li ◽  
Chang-Ping Li ◽  
Qiu-Lin Niu ◽  
Shu-Jian Li ◽  
...  
Keyword(s):  
Cutting Force ◽  
Thrust Force ◽  
Rake Angle ◽  
Cutting Edge ◽  
Distribution Model ◽  
Force Distribution ◽  
Force Coefficient ◽  
Cutting Force Prediction ◽  
Drilling Performance ◽  
Step Drill

Abstract At present, the problems that need to be solved urgently in CFRP drilling are delamination and tool wear, which are closely related to the distribution of cutting force on the cutting edge. The aim of this paper is to present a method to analyze the cutting force distribution on the main cutting edge of the drill. This method applies to the analysis of the drilling performance of double point angle (DPA) drill and to optimize the step drill structure for CFRP drilling. Both of these applications prove the correctness of the analysis method. According to the calculation model of the rake angle of the main cutting edge of the twist drill and the cutting force prediction model, the distribution model of the cutting force on the main cutting edge is established. This method reveals the basic reason why the thrust force increases linearly when a single main cutting edge cuts into the workpiece. In the process of analyzing the drilling performance of the DPA drill, the edge force coefficient is used to represent the thrust force, and the application environment of the drill with a different structure is analyzed. Based on the distribution characteristics of the axial force on the main cutting edge, the step ratio of the step drill is optimized. This method can optimize the step ratio of the step drill. This method can be employed to optimize the step ratio of any structure step drill.

Comparisons of the use of twist, pilot-hole and step-drill on influence of carbon fiber-reinforced polymer drilling hole quality

2017 ◽  
Vol 52 (11) ◽  
pp. 1465-1480 ◽  
Author(s):  
Gong-Dong Wang ◽  
Melly S Kirwa
Keyword(s):  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Hole Quality ◽  
Pilot Hole ◽  
Reinforced Polymer ◽  
Thrust Forces ◽  
Step Drill ◽  
Delamination Damage

Understanding the drilling-induced damage to carbon fiber-reinforced polymer composites remains the most active research being undertaken in the composite materials world of today. Despite the vast amounts of literature available, the relationship between drilling and damage to the composites has not been fully understood. In this research, a comparative study of different drilling methods including the use of a twist drill, the use of a pilot hole/pre-drilled hole and the use of a step drill on the influence of the hole quality has been accomplished. In order to achieve this comparison, thrust forces have been monitored during drilling experiments where four different feed rates and one spindle speed have been considered. A finite element model has also been included to study delamination damage on the laminates and validate the experimental results. Results show that thrust forces increase with increasing feed rates and that drilling by step drill is the most appropriate method as it records low forces hence minimal delamination damage.

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