Rake angle effects on ultrasonic-assisted edge trimming of multidirectional CFRP laminates

Abstract Machining of CFRP composites is a process frequently accompanied with adverse effects on machined surface. The geometry of the cutting tool, linked primarily to influencing the cutting mechanism, could largely influence the induced damage. An optimum combination of tool material and geometry could improve the cut quality and prolong the tool life. This article investigates the effect of using tools having different rake angles in an ultrasonic-assisted edge trimming operation when cutting multidirectional CFRP laminates. A full-factorial experimental design was adopted to analyse the effect of parameters typically cutting speed, feed rate, rake angle, amplitude, and their interactions on machining performance indicators captured which were the cutting forces, tool wear, chip temperature, and surface roughness. The results showed that UAM mode contributed to the increase in cutting forces, tool wear, and chip temperature compared to conventional mode. On the other hand, UAM mode improved the quality of the machined surface. Additionally, the ultrasonic mode enhances the material removal mechanism using a tool with a negative rake angle.

Download Full-text

Experimental Investigation of Bouncing-Back of Multidirectional CFRP Laminates during Ultrasonic Assisted Edge Trimming

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.382.109 ◽

2018 ◽

Vol 382 ◽

pp. 109-113

Author(s):

Mohamed O. Helmy ◽

M.H. El-Hofy ◽

Hassan El-Hofy

Keyword(s):

Feed Rate ◽

Depth Of Cut ◽

Spring Back ◽

Cfrp Laminates ◽

Radial Depth ◽

Ultrasonic Assisted ◽

Ultrasonic Assisted Machining ◽

End Mills ◽

Edge Trimming

Edge trimming process is needed for finishing CFRP components to the required accuracy and surface quality. The bouncing–back effect of CFRP components is very challenging owing to spring back of trimmed edge after cutting tool pass. Ultrasonic assisted machining (UAM) is an efficient method used to enhance the quality of CFRP parts due to the reduced contact time between the tool and workpiece. This paper experimentally investigates the effect of edge trimming variables on the cutting forces and the magnitude of the bouncing back. Diamond abrasive end mills were utilized during ultrasonic assisted edge trimming of CFRP. The processes variables include spindle speed, feed rate, radial depth of cut, fiber orientations, and up/down strategy. Statistical analysis was conducted to determine the most significant factor on performance characteristics. Regression equation was also developed to predict the value of bouncing back. The results showed that depth of cut and feed rate have a significant effect on bouncing back among the process variables.

Download Full-text

Influence of process parameters on the ultrasonic assisted edge trimming of aerospace CFRP laminates using MQL

International Journal of Machining and Machinability of Materials ◽

10.1504/ijmmm.2020.109844 ◽

2020 ◽

Vol 22 (5) ◽

pp. 349

Author(s):

Mohamed O. Helmy ◽

M.H. El Hofy ◽

Hassan El Hofy

Keyword(s):

Process Parameters ◽

Influence Of Process Parameters ◽

Cfrp Laminates ◽

Ultrasonic Assisted ◽

Edge Trimming

Download Full-text

Influence of process parameters on the ultrasonic assisted edge trimming of aerospace CFRP laminates using MQL

International Journal of Machining and Machinability of Materials ◽

10.1504/ijmmm.2020.10030613 ◽

2020 ◽

Vol 22 (5) ◽

pp. 349

Author(s):

Hassan El Hofy ◽

Mohamed O. Helmy ◽

M.H. El Hofy

Keyword(s):

Process Parameters ◽

Influence Of Process Parameters ◽

Cfrp Laminates ◽

Ultrasonic Assisted ◽

Edge Trimming

Download Full-text

The effect of fiber orientation on tool wear in edge-trimming of carbon fiber reinforced plastics (CFRP) laminates

Wear ◽

10.1016/j.wear.2020.203213 ◽

2020 ◽

Vol 450-451 ◽

pp. 203213

Author(s):

Dinh Nguyen ◽

Mohammad Sayem Bin Abdullah ◽

Ryan Khawarizmi ◽

Dave Kim ◽

Patrick Kwon

Keyword(s):

Carbon Fiber ◽

Tool Wear ◽

Fiber Orientation ◽

Fiber Reinforced ◽

Cfrp Laminates ◽

Carbon Fiber Reinforced Plastics ◽

Reinforced Plastics ◽

Fiber Reinforced Plastics ◽

Carbon Fiber Reinforced ◽

Edge Trimming

Download Full-text

A New Cutting Device Design to Study the Orthogonal Cutting of CFRP Laminates at Different Cutting Speeds

Materials ◽

10.3390/ma12244074 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4074 ◽

Cited By ~ 1

Author(s):

Víctor Criado ◽

Norberto Feito ◽

José Luis Cantero Guisández ◽

José Díaz-Álvarez

Keyword(s):

Orthogonal Cutting ◽

Cutting Speed ◽

Cutting Parameters ◽

Rake Angle ◽

Linear Displacement ◽

Tool Geometry ◽

Cfrp Laminates ◽

Reinforced Plastics ◽

Wide Range ◽

Cutting Speeds

Carbon Fiber-reinforced plastics (CFRPs) are widely used in the aerospace industry due to their highly mechanical properties and low density. Most of these materials are used in high-risk structures, where the damage caused by machining must be controlled and minimized. The optimization of these processes is still a challenge in the industry. In this work, a special cutting device, which allows for orthogonal cutting tests, with a linear displacement at a wide range of constant cutting speeds, has been developed by the authors. This paper describes the developed cutting device and its application to analyze the influence of tool geometry and cutting parameters on the material damage caused by the orthogonal cutting of a thick multidirectional CFRP laminate. The results show that a more robust geometry (higher cutting edge radius and lower rake angle) and higher feed cause an increase in the thrust force of a cutting tool, causing burrs and delamination damage. By reducing the cutting speed, the components with a higher machining force were also observed to have less surface integrity control.

Download Full-text

Edge Trimming of Aluminum Sheets Using Shear Slitting at a Rake Angle

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2336258 ◽

2006 ◽

Vol 128 (4) ◽

pp. 866-873 ◽

Cited By ~ 2

Author(s):

Hongbing Lu ◽

Jin Ma ◽

Ming Li

Keyword(s):

Relative Motion ◽

Sheet Thickness ◽

Rake Angle ◽

Aluminum Sheet ◽

Early Separation ◽

Burr Height ◽

Aluminum Sheets ◽

Wide Range ◽

Blade Edge ◽

Edge Trimming

Edge burr is inevitably present at a slit edge when an aluminum web is shear slit by a pair of rotary knives (or blades) engaged and rotated in opposite directions. This paper presents a new method of shear slitting for an aluminum sheet to produce very low edge burr height, for use in edge trimming. The method uses the same bottom rotary blade as in the traditional shear slitting, but a revised top blade that forms a rake angle with respect to the bottom blade. The top blade edge is chamfered so that the surface of the top blade edge is parallel to the surface of the bottom blade edge to produce a pair of shearing surfaces to shear slit the aluminum sheet. A sequential set of micrographs of an aluminum slit edge are taken to visualize different stages of the shear slitting process. The observation indicates that this new slitting configuration induces a local tension as a result of blade relative motion so that a combined tension∕shear is applied to the aluminum sheet to facilitate early separation in the aluminum sheets. As a result, a clean edge with very small burr height is produced consistently. Edge trimming of aluminum sheet over a wide range of slitting conditions indicates that the new configuration is insensitive to blade gap and overlap, and can lead to a clean cut with very low edge burr height even when two blades are separated by a gap that is a few times of the sheet thickness.

Download Full-text