Study of drilling-induced defects for CFRP composites using new criteria

Xu, Jinyang; Li, Chao; Mi, Sipei; An, Qinglong; Chen, Ming

doi:10.1016/j.compstruct.2018.06.051

Cited by 171 publications

(80 citation statements)

References 30 publications

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“…The material properties of NRF are different than the material properties of the matrix material (epoxy resin) and of the reinforcing fibers (carbon), the machinability of these NRF is therefore different too. Special cutting tools for CFRP machining are usually (i) good in wear resistance against carbon fibers [53][54][55][56][57][58], (ii) excellent in minimizing delamination [59][60][61][62], furthermore, (iii) they are good in reducing the number of uncut reinforcing fibers [63][64][65][66]. Nevertheless, these special cutting tools usually do not cut properly NRF.…”

Section: Results Of Drilling Experimentsmentioning

confidence: 99%

Analysis of Characteristics of Surface Roughness of Machined CFRP Composites

Geier

Pereszlai

2019

Period. Polytech. Mech. Eng.

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Measuring and characterizing of surface roughness of machined surfaces of carbon fiber reinforced polymer (CFRP) composites are difficult due to the occurrence of special surface damages (delamination, uncut fibers, fiber pull-outs or micro-cracks, etc.). The main objective of the present study is to analyze the characteristics of surface roughness of machined unidirectional CFRP in detail. Numerous conventional drilling, helical milling, and edge trimming experiments were carried out with different cutting tools in order to analyze the influence of them on the average surface roughness (Ra), on the roughness depth (Rz) and on the Rz /Ra parameter. The surface roughness was measured by a Mitutoyo SJ-400 contact profilometer and an Alicona Infinite Focus confocal microscope. The usability of the contact profilometer was experimentally tested and compared its results with the results of the confocal microscope. Experimental results show that the contact profilometer is suitable for measuring surface roughness of CFRP, furthermore, values of Rz /Ra of drilled and edge trimmed surfaces of unidirectional CFRP are changing in a wide interval: from 5 to 14 μm/μm due to the special surface damages. Based on this research, the machinability analysis of CFRP is suggested to be extended to the analysis of the Rz /Ra parameter.

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Section: Results Of Drilling Experimentsmentioning

confidence: 99%

Analysis of Characteristics of Surface Roughness of Machined CFRP Composites

Geier

Pereszlai

2019

Period. Polytech. Mech. Eng.

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“…In case improper machining technology is applied when machining CFRPs, many micro-and macro-geometrical damages can be generated easily: such damages include delamination [6,7,[14][15][16][17][18][19][20][21][22][23][24], uncut fibres and pull-outs [13,[25][26][27][28][29][30][31] as well as microcracks on the machined surfaces [30,[32][33][34]. In order to minimize the above-listed damages, there are many process and technological parameters that have to be optimized including (i) the geometry and coating of the cutting tool [18,33]; (ii) the cutting speed, feed rate and the depth of cut [7,18,35]; (iii) the tool path [7,13,32]; (iv) the cooling [36][37][38][39]; and (v) the type of support plate [40][41][42].…”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of wobble milling, helical milling and conventional drilling of CFRPs

Pereszlai

Geier

2020

Int J Adv Manuf Technol

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Due to its excellent specific mechanical properties, carbon fibre-reinforced polymer (CFRP) composite is a widely used structural material in the aerospace industry. However, this material is difficult to cut, mainly due to its inhomogeneity and anisotropic features and because of the strong wear effects of its carbon fibres. In the scope of aerospace industrial uses of this material, thousands of holes have to be machined for purposes of assembly. Nevertheless, conventional drilling technologyeven if special drilling tools are usedis only moderately able to manufacture good quality holes. Wobble milling is a novel advanced hole-making technology, which has been developed to minimize machining-induced geometrical defects like delamination or uncut fibres. The main objective of the present paper is to compare wobble milling, helical milling and conventional drilling technologies concerning unidirectional CFRPs. In addition, the kinematics of wobble milling technology is discussed in detail. In the scope of this paper, numerous machining experiments were conducted in unidirectional CFRPs: herein the impact of the type of cutting tool and of process parameters on the quality of machined holes are analysed and discussed (diameter of holes, circularity error and characteristics of uncut fibres). During these investigations, experimental data were evaluated with the help of digital image processing (DIP) and with the help of analysis of variance (ANOVA) techniques. Experimental results show that the amount of uncut fibres can significantly be minimized through the application of wobble milling technology.

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“…Delamination damage deteriorates the mechanical properties of the machined part and reduces in-service life due to fatigue [12,13]. Research efforts have focused on the selection of machining parameters aimed at overcoming the delamination issue [5,6,[14][15][16]. Delamination defects have been attributed mainly to higher thrust forces [13].…”

Section: Introductionmentioning

confidence: 99%

Chip Morphology and Delamination Characterization for Vibration-Assisted Drilling of Carbon Fiber-Reinforced Polymer

Hussein

Sadek

Elbestawi

et al. 2019

JMMP

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Carbon fiber-reinforced polymers (CFRP) are widely used in the aerospace industry. A new generation of aircraft is being built using CFRP for up to 50% of their total weight, to achieve higher performance. Exit delamination and surface integrity are significant challenges reported during conventional drilling. Exit delamination influences the mechanical properties of machined parts and, consequently, reduces fatigue life. Vibration-assisted drilling (VAD) has much potential to overcome these challenges. This study is aimed at investigating exit delamination and geometrical accuracy during VAD at both low- and high-frequency ranges. The kinematics of VAD are used to investigate the relationship between the input parameters (cutting speed, feed, vibration frequency, and amplitude) and the uncut chip thickness. Exit delamination and geometrical accuracy are then evaluated in terms of mechanical and thermal load. The results show a 31% reduction in cutting temperature, as well as a significant enhancement in exit delamination, by using the VAD technology.

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Study of drilling-induced defects for CFRP composites using new criteria

Cited by 171 publications

References 30 publications

Analysis of Characteristics of Surface Roughness of Machined CFRP Composites

Analysis of Characteristics of Surface Roughness of Machined CFRP Composites

Comparative analysis of wobble milling, helical milling and conventional drilling of CFRPs

Chip Morphology and Delamination Characterization for Vibration-Assisted Drilling of Carbon Fiber-Reinforced Polymer

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