Optimization of Delamination and Thrust Force in the Drilling Process of Nanocomposites

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.

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Dynamic characteristics of a drill in the drilling process

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/095440503321148803 ◽

2003 ◽

Vol 217 (2) ◽

pp. 161-167 ◽

Cited By ~ 10

Author(s):

B W Huang

Keyword(s):

Dynamic Characteristics ◽

High Speed ◽

Thrust Force ◽

Time Dependent ◽

Drilling Process ◽

Improve Quality ◽

Vibration Model ◽

High Speed Drilling ◽

Spinning Speed ◽

Twisted Beam

The dynamic characteristics of high-speed drilling were investigated in this study. To improve quality and produce a higher production rate, the dynamic characteristics of the drilling process need to be studied. A pre-twisted beam is used to simulate the drill. The moving Winkler-type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The spinning speed, pre-twisted angle and thrust force effects of the drill are considered. The numerical analysis indicates that the natural frequency is suddenly reduced as the drill moves into a workpiece.

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A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

Mathematical Problems in Engineering ◽

10.1155/2015/952049 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Qiang Fang ◽

Ze-Min Pan ◽

Bing Han ◽

Shao-Hua Fei ◽

Guan-Hua Xu ◽

...

Keyword(s):

Cutting Force ◽

Thrust Force ◽

Cutting Parameters ◽

Force Model ◽

Drilling Process ◽

Reinforced Plastics ◽

Orbital Drilling ◽

Drilling Parameters ◽

Drilling Operations ◽

Machining Properties

Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti) stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm) before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.

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Fuzzy Logic in Hole Drilling of Composites

4th Flexible Assembly Conference ◽

10.1115/detc1994-0363 ◽

1994 ◽

Author(s):

Aditya Thadani ◽

Athamaram H. Soni

Keyword(s):

Fuzzy Logic ◽

Fuzzy Logic Controller ◽

Thrust Force ◽

Cutting Speed ◽

Research Data ◽

Theoretical Research ◽

Hole Drilling ◽

Tool Geometry ◽

Drilling Process ◽

And Control

Abstract Experimental and theoretical research data was utilized in building a Fuzzy Logic Controller model applied to simulate the drilling process of composite materials. The objective is to have a better understanding and control of delamination of composites during the drilling process and at the same time to improve the hole finish by controlling fraying and splintering. By controlling the main issues in the drilling process such as feed rate, cutting speed, thrust force, and torque generated in addition to the tool geometry, it is possible to optimize the drilling process avoiding the conventionally encountered problems.

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Experiments of Drilling Titanium Alloy with Varying Operation Parameters

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.748.254 ◽

2017 ◽

Vol 748 ◽

pp. 254-258

Author(s):

Chang Yi Liu ◽

Bai Shou Zhang ◽

Suman Shrestha

Keyword(s):

Titanium Alloy ◽

Feed Rate ◽

Thrust Force ◽

Maximum Amount ◽

Spindle Speed ◽

Drilling Process ◽

Process Variables ◽

Experimental Cutting ◽

Operation Parameters ◽

Titanium Alloy Ti6al4v

Drilling experiments of titanium alloy Ti6Al4V were conducted. Taking the speed and feed as the process variables, a set of experimental cutting forces are obtained and compared. From the experimental results it is concluded that within the experimental extent the thrust force and torque of drilling process rises with the feed rate. The lower spindle speed resulted in the greater amount of thrust. Feed rates have greater influence on the thrust force than the spindle speed. The combination of greater feed rate and lower spindle speed results in the maximum amount of thrust. However, combination of greater feed rate and spindle speed resulted in maximum amount of torque.

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Effects of Twist Drill Point Angle on Thrust Force and Delamination Factor in Hybrid Fiber Composites Drilling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.564.501 ◽

2014 ◽

Vol 564 ◽

pp. 501-506 ◽

Cited By ~ 2

Author(s):

Mohd Azuwan Maoinser ◽

Faiz Ahmad ◽

Safian Shariff ◽

Tze Keong Woo

Keyword(s):

Feed Rate ◽

Thrust Force ◽

Polymeric Composite ◽

Drilling Process ◽

Twist Drill ◽

Fiber Reinforced ◽

Hybrid Fiber ◽

Frp Composites ◽

Delamination Factor ◽

Drill Point

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.

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Using artificial neural network models for the prediction of thrust force and torque in drilling operation of Al7075

MATEC Web of Conferences ◽

10.1051/matecconf/201817801008 ◽

2018 ◽

Vol 178 ◽

pp. 01008

Author(s):

Panagiotis Kyratsis ◽

Nikolaos Efkolidis ◽

Daniel Ghiculescu ◽

Konstantinos Kakoulis

Keyword(s):

Thrust Force ◽

Network Models ◽

Cutting Parameters ◽

Drilling Process ◽

Neural Network Models ◽

Cutting Velocity ◽

Artificial Neural ◽

Hidden Layer ◽

The One ◽

Tool Diameter

This study investigates the thrust force (Fz) and torque (Mz) in a drilling process of an Al7075 workpiece using solid carbide tools (Kennametal KC7325), depending on the effects of crucial cutting parameters such as cutting velocity, feed rate and tool diameter of 10mm, 12mm and 14mm. Artificial neural networks (ANN) methodology is used in order to acquire mathematical models for both the thrust force (Fz) and torque (Mz) related to the drilling process. The ANN results showed that the best prediction topology of the network for the thrust force was the one with five neurons in the hidden layer, while for the case of Mz the best network topology for the prediction of the experimental values was the one with six neurons in the hidden layer. Based on the results acquired, the ANN models achieved accuracy of 1,96% and 1,95% for both the thrust force and torque measured, while the R coefficient for the prediction model of the thrust force is 0.99976 and 00.99981 for the torque. As a result they can be considered as very accurate and appropriate for their prediction.

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The Drilling Vibration Behavior of a Twisted Microdrill

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1813472 ◽

2004 ◽

Vol 126 (4) ◽

pp. 719-726 ◽

Cited By ~ 27

Author(s):

Bo-Wun Huang

Keyword(s):

Dynamic Characteristics ◽

Printed Circuit Boards ◽

Thrust Force ◽

Time Dependent ◽

Drilling Process ◽

Improve Quality ◽

Circuit Boards ◽

Rotating Speed ◽

Printed Circuit ◽

Vibration Model

The dynamic characteristics of a microdrill in the drilling process were investigated in this study. The trend toward higher density printed circuit boards requires smaller holes, down to 0.3 mm in diameter, to be drilled through the board layers. To improve quality, produce a higher production rate, and avoid drill breakage, the dynamic characteristics of the microdrilling process must be studied. A stepped pretwisted beam is used to simulate the microdrill. A moving Winkler-Type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The rotating speed, pretwisted angle, and thrust force effects of the microdrill are considered. The numerical analysis indicates that the natural frequency is reduced suddenly as the microdrill moves into a workpiece.

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Drilling Force and Chip Morphology in Drilling of PCB Supported Hole

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.188.429 ◽

2011 ◽

Vol 188 ◽

pp. 429-434 ◽

Cited By ~ 11

Author(s):

L.P. Yang ◽

Li Xin Huang ◽

Cheng Yong Wang ◽

L.J. Zheng ◽

Ping Ma ◽

...

Keyword(s):

Feed Rate ◽

Printed Circuit Board ◽

Thrust Force ◽

Chip Morphology ◽

Cutting Parameters ◽

Spindle Speed ◽

Circuit Board ◽

Drilling Process ◽

Drilling Force ◽

Drill Bits

Supported holes of Printed circuit board (PCB) are drilled with two different drill bits. Drilling force (thrust force and torque) and chip morphology are examined at different cutting parameters, and the effects of the two drills are discussed. The results indicate that the drilling force and chip morphology are affected by the feed rate, spindle speed and drill shape. Thrust force increases with the increasing feed rate, and decreases with the increasing spindle speed. Optimization of drill geometry can reduce the thrust force significantly, and is effective in chip breaking which can improve the chip evacuation during the drilling process.

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Finite Element Method Simulation of Drilling Process on Metal-Matrix Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.188.372 ◽

2011 ◽

Vol 188 ◽

pp. 372-375

Author(s):

H.L. Zhang ◽

Jin Chen

Keyword(s):

Finite Element ◽

Feed Rate ◽

Shear Failure ◽

Thrust Force ◽

Equivalent Stress ◽

Damage Model ◽

Cutting Speed ◽

Finite Element Method Simulation ◽

Drilling Process ◽

Machining Processes

Drilling is one of the complex machining processes, which has been widely applied in the manufacturing area. In this paper, a 3D coupled thermo-mechanical finite element model was used for simulating the thrust force, torque and von Mises equivalent stress at different cutting conditions. The J-C damage model (shear failure) was used in conjunction with the J-C plasticity model, as well as the continuous adaptive remeshing technical. The results show that the thrust force and torque increase with the increasing of the cutting speed and feed rate, and the influence of the feed rate is more obviously.

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