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Publication Circular economy innovation: A deep investigation on 3D printing of industrial waste polypropylene and carbon fibre composites(Elsevier, 2024-04-30) Ghabezi, Pouyan; Sam-Daliri, Omid; Flanagan, Tomas; Walls, Michael; Harrison, Noel M.; European Union's Horizon 2020; Science Foundation Ireland; Enterprise IrelandTransforming waste polypropylene (PP) and waste carbon fibre into upcycled composite materials for additive manufacturing represents an ideal circular economy challenge. An optimized method for material extrusion and 3D printing was developed to overcome adhesion and warpage challenges during printing. The study explored the impact of varying waste carbon fibre weight fractions (0 wt%, 2 wt%, 5 wt%, 8 wt%, 15 wt%, and 25 wt%), firstly on the properties of filament and then on printability and mechanical properties of printed specimens. Optimized extrusion parameters yielded the successful fabrication of fibre-reinforced filaments. Micro-level assessment of the polymer revealed a decrease in mechanical properties due to thermal processes during filament making and 3D printing. Microstructural analysis, along with optical and scanning electron microscopy, provided insights into inter-bead voids, debonding, fibre dispersion, fracture modes, and filament/sample quality. Differential Scanning Calorimetry indicated slight matrix degradation during filament extrusion, leading to slightly reduced melting and crystallization temperatures.Publication Upcycling waste polypropylene with basalt fibre reinforcement enhancing additive manufacturing feedstock for advanced mechanical performance(Elsevier, 2024-10-25) Ghabezi, Pouyan; Sam-Daliri, Omid; Flanagan, Tomas; Walls, Michael; Harrison, Noel M.; European Union's Horizon 2020; Taighde Éireann/Research Ireland (formerly Science Foundation Ireland)This research seeks to overcome the printing and processing challenges of using waste polypropylene (PP) reinforced with short basalt fibres, transforming them into upcycled feedstock for additive manufacturing. It introduces an optimised method for producing filaments and 3D printing with these materials, addressing common issues such as adhesion and warpage through innovative techniques while achieving maximum mechanical performance in the resulting composites. Basalt fibre weight fractions of 0 %, 2 %, 5 %, 8 %, 15 %, 30 %, and 50 % were used to reinforce the recycled polypropylene, improving both printability and mechanical properties. The tensile strength reached 53.58 MPa at 15 % fibre content, while the flexural strength peaked at 34.06 MPa with 30 % fibre content, revealing distinct interactions between the fibres and polymer under tensile and flexural loading that were not previously observed. Microstructure, voids, debonding, and dispersion were examined using optical and scanning electron microscopy. Differential Scanning Calorimetry (DSC) was performed to assess the thermal behaviour and crystallinity of the recycled polymer during filament production and printing, revealing slight matrix degradation during these processes. The findings highlight the potential of waste basalt fibre-reinforced PP as a valuable filament feedstock for 3D printing, supporting a circular economy approach to composite manufacturing.Publication Multi-scale modelling and life prediction of aged composite materials in salt water(SAGE Publications and American Society for Composites, 2023-02-23) Ghabezi, Pouyan; Harrison, Noel; Science Foundation Ireland; Enterprise IrelandTidal turbine infrastructure is currently in the large-scale prototype and short-term demonstration phase. However, the immediate requirement is to develop materials, processes and long-term life predictive facilities for tidal turbine plant that has decades of operational lifetime requirements. Computational modelling is a key tool to interpret the experimental data, understand the relevant mechanisms and provide a predictive capability for the performance of aged components for industries. The goal of this paper is a prediction of the long-term life of marine-based glass/epoxy and carbon/epoxy composite laminates aged in artificial seawater with 3.5% salinity based on Arrhenius degradation theory and tensile strength retention over 180 days ageing at room temperature and 60°C. Three different analytical models (linear and exponential) were implemented to calculate time shift factors and corresponding life in a real marine environment. Additionally, multi-scale modelling has been implemented via a representative volume element approach for square and hexagonal cells, and two-step homogenization of textile composites in accordance with nanoindentation testing for matrix/resin cells and fibre constraint cells after 90 days of immersion in saltwater. In general, the multi-scale modelling in ABAQUS and TexGen4SC was able to approximate (with about 10% difference) the mechanical properties of dry and aged composite laminates.Publication Degradation characteristics of 3D printed continuous fibre-reinforced PA6/chopped fibre composites in simulated saltwater(Springer, 2024-05-16) Ghabezi, Pouyan; Flanagan, Tomas; Walls, Michael; Harrison, Noel M.; European Union Horizon 2020; Science Foundation Ireland; Enterprise Ireland; IReL ConsortiumThis paper investigates the performance of continuous fibre-reinforced 3D printed components in salt water medium at room temperature. Markforged® Mark Two 3D printer was employed to fabricate standard specimens made of Onyx and reinforced Onyx specimens with continuous carbon, high-strength high-temperature glass, and Kevlar fibres. Aging process was conducted to characterize the long-term effect of salt water on the mechanical behaviour of fibre-reinforced 3D printed samples. Several mechanical tests including tensile, 3-point bending test and indentation testing have been carried out on the dry and aged standard samples to evaluate tensile strength, flexural strength, micro-hardness, and modulus of elasticity in micro-scale. The mechanical tests revealed the degradation and loss in mechanical properties of the printed samples after aging in salt water. The data highlighted that Onyx samples without continuous fibres experienced the most significant reduction in both tensile (33.54%) and flexural (63.47%) strengths after 1 year, while continuous carbon fibre-reinforced Onyx samples showed comparatively lower strength reductions (28.46% in tensile strength and 18.73% in flexural strength). Optical and scanning electron microscopy were performed to investigate the fracture behaviour of the tested specimens. In addition, the DSC assessment showed a slight change in the thermal properties of aged specimens.Publication First-principles study of electronic properties of Zn and La doped and co-doped anatase TiO2(AIP Publishing, 2023-12-12) Christhunathan, Vivek; Farràs, Pau; Tong, Mingming; University of Galway College of Science and EngineeringAb initio computational modeling, based on Density Functional Theory, was employed to predict the influence of metal ions Zn2+ and La3+ on structural, electronic, and photocatalytic properties of anatase TiO2. Specifically, chemical modification of TiO2 was conducted by doping and co-doping the TiO2 using these ions. Properties of the chemically modified TiO2 were computationally predicted in terms of lattice parameters, electronic band structure, density of states, charge density, and absorption spectrum. It was found that co-doping TiO2 using Zn2+ and La3+ significantly reduced the bandgap and improved relative stability, and enhanced photocatalytic activity in the visible-light region was observed in comparison with pure TiO2. This research also interprets the underlying mechanism regarding why the doping and co-doping may have such influences on the properties of the chemically modified TiO2.Publication Evaluation of the performance and complexity of water quality models for peatlands(Elsevier, 2024-11-30) Opoku-Agyemang, Emmanuel; Healy, Mark; Tong, Mingming; Environmental Protection AgencyRewetting is accepted as an effective technique in restoring degraded peatlands. However, it may adversely impact water quality, particularly in nutrient-rich peatlands. The aim of this study was to review water quality models applied to peatlands, with a focus on evaluating the performance (such as stability and accuracy) and complexity of the models. In a systematic review of published studies from 01/01/2003 to 10/12/2023, out of 3618 published studies on peatlands and nutrient modelling, only 23 studies applied water quality models to predict the evolution and distribution of nutrients of peatlands by using 16 different water quality models. Out of the 23 studies, only 1 predicted the nutrient concentration and transport of a rewetted peatland. Among the 16 models evaluated, only the mixed mire water and heat (MMHW) model was capable of considering the inherent heterogeneity in peatland characteristics. The HYDRUS 1D/2D model is effective at predicting nitrogen species, despite encountering challenges in some studies due to the complex nature of the peat environment. To enhance the predictive power of water quality models, it is important to consider all the processes that can affect the concentration of nutrients in peatlands such as oxidation of carbon, the nitrogen cycle, decay/production rate for nutrients, adsorption/desorption of nutrients in the soil, and the advection of nutrients due to the influence of ground water and surface water. To date, no peatland-specific water quality model has been developed to simultaneously predict DOC, nitrogen and phosphorus in peatland ecosystems.Publication Review of particle-based computational methods and their application in the computational modelling of welding, casting and additive manufacturing(MDPI, 2023-08-03) Tong, Mingming; Science Foundation IrelandA variety of particle-based methods have been developed for the purpose of computationally modelling processes that involve, for example, complex topological changes of interfaces, significant plastic deformation of materials, fluid flow in conjunction with heat transfer and phase transformation, flow in porous media, granular flow, etc. Being different from the conventional methods that directly solve related governing equations using a computational grid, the particle-based methods firstly discretize the continuous medium into discrete pseudo-particles in mathematics. The methods then mathematically solve the governing equations by considering the local interaction between neighbouring pseudo-particles. Such solutions can reflect the overall flow, deformation, heat transfer and phase transformation processes of the target materials at the mesoscale and macroscale. This paper reviews the fundamental concepts of four different particle-based methods (lattice Boltzmann method—LBM, smoothed particle hydrodynamics—SPH, discrete element method—DEM and particle finite element method—PFEM) and their application in computational modelling research on welding, casting and additive manufacturing.Publication Direct Flux via Virtual Faces (DFVF-overset): Interpolation-free, conservative, overset CFD using a generalised finite volume method(Elsevier, 2023-10-18) Devlin, James; Chandar, Dominic; Quinlan, Nathan J.; Irish Research CouncilWe present DFVF-overset (Direct Flux via Virtual Faces), a conservative overset scheme based on a general form of the finite volume method, originally derived for a meshless method, which intrinsically supports overlapping cells. Fluxes pass between overlapping cells through virtual faces which have rigorously defined area. Exact conservation is retained, and the method does not require interpolation between constituent grids. The new technique has been implemented as a preprocessor for the open-source CFD library OpenFOAM, and validated for a number of 1D and 2D cases. In a 1D diffusion case, the method converges to an analytical solution in the second order. For the lid-driven cavity, DFVF-overset results are close to single-grid solutions and display similar convergence towards a benchmark solution. The new method produces smooth velocity fields, and on a relatively coarse grid, it resolves a tertiary vortex which is absent in interpolation-based overset solutions. In static and dynamic multiphase cases solved with a volume-of-fluid method, conventional overset schemes display loss of liquid mass, whereas DFVF-overset demonstrates strict conservation of mass and close agreement with single-grid solutions. The new technique shows promise for applications where conventional overset is unsuitable due to interpolation errors or lack of conservation.Publication Effect of corrosion pit on fatigue damage and failure in powder bed fusion AlSi10Mg(Wiley, 2024-05-13) Leen, Sean B.; Science Foundation IrelandThis paper is concerned with environmental corrosion during service of load-bearing aluminum alloys fabricated by additive manufacturing (AM) with a focus on damage evolution characterisation and identification of dominated failure mechanisms of pre-corroded selective laser melted aluminum alloy. An experimental strategy for analysis of the damage and failure process is presented, combining 3D surface measurement, 3D digital image correlation and scanning electron microscopy, to provide multi-source experimental characterization of corrosion morphology, strain field evolution and fracture morphology. Statistics and machine learning methods were employed to process the measured multi-source experimental data, showing that local average roughness has a strong influence on macro-crack initiation position. The analysis focuses on four primary types of fatigue micro-crack initiation, namely internal defects, corrosion platform, corrosion micro-pit and corrosion jut-in; internal defects and corrosion platform are unique features for powder bed fusion (PBF) AlSi10Mg. The micro-crack initiation mechanisms for all four types are (i) local stress concentrations due to adjacent material micro-structural defects, (ii) interaction of underlying alloy microstructure and corrosion-induced stress/strain, and (iii) local stress/strain concentration at corrosion micro-pit and jut-in, respectively.Publication Combined Gleeble physical welding simulation and low-cycle thermo-mechanical fatigue for heat-affected zone material for 9Cr steel: Experimental testing and through-process model(SAGE Publications, 2024-06-13) MacArdghail, Padraig; Barrett, Richard A.; Harrison, Noel; Sabirov, Ilchat; LLorca, Javier; Leen, Seán B.; Science Foundation IrelandThere is an urgent need to operate thermal power plant at significantly higher temperatures, pressures and flexibility, in order to reduce emissions, increase efficiency and facilitate uptake of renewable energy. This demands significantly improved design of welded connections for thermo-mechanical fatigue (TMF). A common mode of high temperature failure for welded 9Cr steels in such plant is Type IV failure, due to reduced hardness in the inter-critical heat affected zone (IC-HAZ). Little or no work has been previously conducted on TMF characterisation of HAZ of 9Cr steels. This work presents development of a combined Gleeble physically-simulated welding process for P91 heat affected zone, based on measured thermal histories from bead-on-plate welding trials, with in-situ low cycle thermo-mechanical fatigue up to 650°C. The simulated welding process, including post-weld heat treatment (PWHT), is shown to have significant effect on both microstructure and TMF behaviour, including life. The as-welded condition is shown to have the cyclically hardest stable response and the longest life, whereas the PWHT and parent material (PM) cases have similar cyclically soft responses and lives. A recently-developed through-process, physically-based, thermal-metallurgical-mechanical model is adapted and applied to the simulated welding thermal cycle and TMF testing for PM and HAZ specimens. The model is calibrated and validated against high temperature low-cycle fatigue and low-cycle TMF data for PM in the range 400 to 600°C, for different strain-ranges and strain-rates. It is also shown to capture some observed general trends for the simulated HAZ-TMF testing, especially the significant softening effect of PWHT and the significant increase in cyclic strength for the as-welded condition.Publication Efficiency and accuracy of GPU-parallelized Fourier spectral methods for solving phase-field models(Elsevier, 2023-06-15) Boccardo, Adrian; Tong, Mingming; Leen, Sean B.; Tourret, Damien; Segurado, Javier; Science Foundation Ireland; Spanish Ministry of Science; Horizon 2020Phase-field models are widely employed to simulate microstructure evolution during processes such as solidification or heat treatment. The resulting partial differential equations, often strongly coupled together, may be solved by a broad range of numerical methods, but this often results in a high computational cost, which calls for advanced numerical methods to accelerate their resolution. Here, we quantitatively test the efficiency and accuracy of semi-implicit Fourier spectral-based methods, implemented in Python programming language and parallelized on a graphics processing unit (GPU), for solving a phase-field model coupling Cahn–Hilliard and Allen–Cahn equations. We compare computational performance and accuracy with a standard explicit finite difference (FD) implementation with similar GPU parallelization on the same hardware. For a similar spatial discretization, the semi-implicit Fourier spectral (FS) solvers outperform the FD resolution as soon as the time step can be taken 5 to 6 times higher than afforded for the stability of the FD scheme. The accuracy of the FS methods also remains excellent even for coarse grids, while that of FD deteriorates significantly. Therefore, for an equivalent level of accuracy, semi-implicit FS methods severely outperform explicit FD, by up to 4 orders of magnitude, as they allow much coarser spatial and temporal discretization.Publication Experimental characterization and strengthening mechanism of process-structure-property of selective laser melted 316 L(Elsevier, 2023-03-02) Chen, Yefeng; Wang, Xiaowei; Li, Dong; Zhou, Dewen; Jiang, Yong; Yang, Xinyu; Liu, Chenglu; Leen, Sean B.; Gong, Jianming; Science Foundation IrelandHeat treatment is the most common method to relieve residual stress and to adjust tensile properties in additively manufactured material. However, the well-known strengthening factors (e.g., dislocation density, cellular sub-structure, low angle grain boundaries, nano-oxide particle) in selective laser melted 316 L (SLM 316 L) are strongly influenced by heat-treatment temperature. In this work, horizontal and vertical oriented SLM 316 L specimens are heat treated from 550 °C to 1150 °C, followed by tensile tests and microstructural characterization. With increasing temperature, strength (e.g., yield strength, ultimate tensile strength) is found to decrease and elongation is found to increase. The heat treatments of 550 °C, 650 °C and 750 °C lead to coarsening of cellular sub-structure. Furthermore, the cellular sub-structure and melt boundaries annihilate at 950 °C. When the temperature reaches 1150 °C, SLM 316 L has finished recrystallization with volume fraction of nano-oxide particles increasing greatly. Based on microstructural characterization, the proposed relationship, considering strengthening mechanisms of cellular sub-structure, nano-oxide particle and grain boundaries, give satisfactory accuracy to predict yield strength for horizontal orientation. The yield strength for vertical orientation can also be predicted by this relationship when modified by consideration of anisotropy of columnar grains and lack-of-fusion defects. The anisotropy and lack-of-fusion lead to 5.4% reduction in yield strength for the vertical orientation. This work establishes quantitative relationships for heat treatment-microstructure-property, in which the anisotropy of tensile properties is considered.Publication Process-structure-property modeling for postbuild heat treatment of powder bed fusion Ti-6Al-4V(SAGE Publications, 2023-07-10) Liu, Jianxin; Yang, Xinyu; Chai, Xingzai; Boccardo, Adrian; Chen, Yefeng; Wang, Xiaowei; Leen, Sean B.; Gong, Jianming; Science Foundation IrelandPostbuild heat treatment is an important component in optimized manufacturing processing for laser beam powder bed fusion (PBF-LB) Ti-6Al-4V. The development of predictive modeling, based on the understanding of the relationships between process parameters, microstructure evolution, and mechanical properties, is a potentially key ingredient in this optimization process. In this paper, a process-structure-property (PSP) model is developed to predict the effect of postbuild heat treatment on yield strength, which is a key tensile property for PBF-LB Ti-6Al-4V. The process-structure part is developed with a focus on the prediction of solid-state phase transformation, especially dissolution of martensite during the heating phase. Subsequent tensile properties are quantified by a microstructure-sensitive yield strength model based on the predicted microstructure variables. The integrated PSP model is validated via experimentally measured phase fraction, α lath width and monotonic tensile tests on PBF-LB Ti-6Al-4V with different heat treatment temperatures, for identification of optimal process parameters.Publication Three-dimensional finite element modelling for additive manufacturing of Ti-6Al-4V components: Effect of scanning strategies on temperature history and residual stress(Elsevier, 2022-03-22) Zhou, Jinbiao; Barrett, Richard A.; Leen, Sean B.; Science Foundation IrelandA key challenge for metal additive manufacturing is the requirement to adapt process-structure-property methods currently under development to realistic, complex geometries. Of specific concern in the present work is the requirement for accurate computation in such realistic geometries of (i) thermal histories, to facilitate microstructure prediction, and hence, mechanical properties, and (ii) residual stresses, as required for accurate assessment and design for structural integrity, such as fatigue cracking. This paper presents three-dimensional, finite element modelling for simulation of a realistic Ti-6Al-4V component using directed energy deposition. The predicted results are successfully validated against published experimental and numerical data. The effects of different scanning strategies on temperature histories and residual stresses are investigated as a basis for identification of optimal manufacturing protocols. Finally, fatigue life predictions of the Ti-6Al-4V component have been considered based on the Basquin-Goodman equation with the effect of residual stress taken into account.Publication Finite element modelling for mitigation of residual stress and distortion in macro-scale powder bed fusion components(SAGE Publications, 2022-12-23) Zhou, Jinbiao; Barrett, Richard A.; Leen, Sean B.; Science Foundation IrelandPowder bed fusion (PBF) has attracted significant attention in many applications due to its capability of fabricating complex and customized metal parts. However, the potential for high inherent residual stresses that produce distortion in additive manufacturing (AM) components prevents more widespread application of the AM technique. Efficient and accurate prediction of residual stress and distortion at component-level (macro-scale) is a complex task. Although process-level (meso-scale) thermo-mechanical simulations have resulted in accurate predictions for small-scale parts, the computational times (typically weeks) and memory requirements for application of such methods to component-level are prohibitive. The main goal of the current study therefore is to present an efficient and accurate finite element (FE) simulation method with detailed validation for PBF manufacture of a complex 3D Inconel 625 benchmark bridge component (macro-scale). The simulation results are successfully validated against the published benchmark experimental measurements from neutron diffraction, X-ray diffraction (XRD), contour method and coordinate measurement machine (CMM) by the National Institute of Standards and Technology (NIST) laboratory. A key additional novelty of the present work is the investigation of the effects of substrate removal and preheating on mitigation of residual stresses and distortions using the validated model. Ultimately, these results will guide the selection of optimal manufacturing protocols and integration of the FE-based AM modelling for industrial application with complex geometries. The ultimate aim of the present work is to facilitate fatigue life prediction of complex geometry AM components including residual stress effects, for example, conformally-cooled injection moulding dies (for different material than Inconel 625).Publication Strategies for mainstreaming education for sustainable development in education systems(Index Copernicus, 2022-06-30) Thakore, Renuka; Nkuba, Michael; Mitchell, Sinéad; Kelkar, AshishA meaningful and relevant ¿Excellence in Education Spaces¿ is imperative so that future generations can address societal risks. This inevitably requires education to integrate strategies to transform the current approaches and build on sustainability strategies. Education for sustainable development (ESD), considered a pivotal vehicle, is, nevertheless, relegated to science and environmental-related courses at most schools and universities. ESD is treated as one off-topic for discussion, creating an information deficit, implying that a few future leaders get knowledge about sustainability. The practices and attitudes about sustainable development goals (SDGs) are not universal, failing to achieve equitable SDGs. A few purposive studies from engineering were analysed to confirm that the ESD must be mainstreamed in education, allowing future generation delegates to build knowledge capital at the individual and institutional levels, equip future practitioners and decision-makers with strategic capabilities to resolve unforeseeable problems, drive societal transformation, and impact climate change, honouring SDGsPublication Portfolio management: The holistic data lifecycle(Drake Management Review, 2022-10) McAvoy, John; Murphy, Conor; Mushtaq, Laila; O’Donnell, James; Brennan, Attracta; Dempsey, Mary; Kiely, GayeMachine learning provides many benefits to Portfolio Managers in analysing data and has the potential to provide much more. A concern with the approach to Machine Learning in Portfolio Management is that is caught between two domains: finance and information systems. In reality, to ensure its success, having these two separate and distinct domains are problematic. What is required is a holistic view, facilitating discussions, with data being the unifying concept and the one that is key to success. The data value map is a lens that allows all involved, in the use or adoption of Machine Learning in Portfolio Management, to form a shared understanding of the lifecycle of the data involved. Rather than being seen as a financial concept or a technical concept, this view of the data lifecycle provides a platform for all involved to determine what is required, and to identify and deal with any potential pitfalls along the way. A holistic view, and shared understanding, are required for the success of Machine Learning in Portfolio Management. Research on the intersection between Machine Learning and Portfolio Management is currently lacking. A focus on the different parts of the data lifecycle provides an opportunity for further research.Publication On the corrosion cracking of austenitic stainless steel in molten solar salt: experiments and modelling(Elsevier, 2022-09-16) Li, Heng; Wang, Xiaowei; Feng, Xiucheng; Yang, Xinyu; Tang, Jianqun; Gong, Jianming; Leen, Sean B.; National Natural Science Foundation of ChinaThe mechanical behaviors of 304 and 316 L steels was investigated in air and in solar salt with different contents of chloride impurity under slow strain rate tensile (SSRT) tests using a novel experimental approach at 565 °C. Results show that the yield strength (YS) and ultimate tensile strength (UTS) are negligibly affected by the molten salt corrosion whereas the ductility decreases with increasing contents of chloride. Corrosion cracks initiate and propagate along the grain boundary due to its higher corrosion rate and incremental oxide rupture. Moreover, a damage model that captures the corrosion and chloride effects is proposed and validated.Publication A review of the most significant challenges impacting conventional Project Management success(Institute of Electrical and Electronics Engineers, 2022-06-29) Dempsey, Mary; Brennan, Attracta; Holzberger, Astrid; McAvoy, JohnTo remain competitive, it is important for organizations to be aware of the success factors for effective conventional project management. It is equally important for them to develop knowledge about project management challenges and how such challenges can be addressed. Organizations and their project management teams are influenced by the three categories of enablers, limitations and challenges. In this study, a review was carried out to highlight the challenges impacting the effectiveness of conventional project management. The review process comprised; identifying the research question; identifying relevant references; selecting studies; charting the data; and collating, summarizing, and reporting results. This process resulted in the inclusion of eight relevant references. Based on the frequency of challenge occurrence, the following five significant challenges have been identified; communication, control, competence, culture, and complexity. Complementarity and dependency links between these five challenges have been highlighted in this paper. In this review paper, some project management challenges may not be presented. Due to the selected databases, search terms, chosen publications, and the authors¿ assessment, the research may have some limitations. Furthermore, the challenges of conventional project management can partly be overcome by a mixture of other project management methods and identified recommendations.Publication Defect evaluation of the honeycomb structures formed during the drilling process(SAGE Publications, 2019-07-02) Ghabezi, Pouyan; Farahani, M.; Shahmirzaloo, Ali; Ghorbani, H.; Harrison, Noel M.In this paper, a comprehensive experimental investigation was carried out to precisely characterize the delamination and uncut fiber in the drilling process. A digital imaging procedure was developed in order to calculate the damage resulted from the drilling process. A novel method is proposed in this article based on image intensity to verify the obtained results. A full factorial experimental design was performed to evaluate the importance of the drilling parameters. Among other process parameters, feed rate, cutting speed, and tool diameter are the principal factors responsible for the delamination damage size during the drilling. The drilling process was assessed based on two proposed incurred damage factors, specifically the delamination factor and uncut fiber factor. Experimental results demonstrated that the feed rate was the paramount parameter for both delamination and uncut fiber factors. It was observed that both factors increased with an increase in the feed rate. Additionally, by increasing the tool diameter, the delamination and uncut fiber factors significantly increase. The effects of the cutting speed on damage factors were not linear. The minimum delamination factor and uncut fiber factor were obtained at the cutting speed of 1500 and 2500â r/min, respectively.In this paper, a comprehensive experimental investigation was carried out to precisely characterize the delamination and uncut fiber in the drilling process. A digital imaging procedure was developed in order to calculate the damage resulted from the drilling process. A novel method is proposed in this article based on image intensity to verify the obtained results. A full factorial experimental design was performed to evaluate the importance of the drilling parameters. Among other process parameters, feed rate, cutting speed, and tool diameter are the principal factors responsible for the delamination damage size during the drilling. The drilling process was assessed based on two proposed incurred damage factors, specifically the delamination factor and uncut fiber factor. Experimental results demonstrated that the feed rate was the paramount parameter for both delamination and uncut fiber factors. It was observed that both factors increased with an increase in the feed rate. Additionally, by increasing the tool diameter, the delamination and uncut fiber factors significantly increase. The effects of the cutting speed on damage factors were not linear. The minimum delamination factor and uncut fiber factor were obtained at the cutting speed of 1500 and 2500â r/min, respectively.