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1 – 10 of over 1000Donghua Zhao, Jiapeng He, Gaohan Zhu, Youcheng Han and Weizhong Guo
The rapid development of three-dimensional (3D) printing makes it familiar in daily life, especially the fused deposition modeling 3D printers. The process planning of traditional…
Abstract
Purpose
The rapid development of three-dimensional (3D) printing makes it familiar in daily life, especially the fused deposition modeling 3D printers. The process planning of traditional flat layer printing includes slicing and path planning to obtain the boundaries and the filling paths for each layer along the vertical direction. There is a clear division line through the whole fabricated part, inherited in the flat-layer-based printed parts. This problem is brought about by the seam of the boundary in each layer. Hence, the purpose of this paper is to propose a novel helical filling path generation with the ideal surface-plane intersection for a rotary 3D printer.
Design/methodology/approach
The detailed algorithm and implementation steps are given with several worked examples to enable readers to understand it better. The adjacent points obtained from the planar slicing are combined to generate each layer's helical points. The contours of all layers are traversed to obtain the helical surface layer and helical path. Meanwhile, the novel rotary four-degree of freedom 3D printer is briefly introduced.
Findings
As a proof of concept, this paper presents several examples based on the rotary 3D printer designed in the authors’ previous research and the algorithms illustrated in this paper. The preliminary experiments successfully verify the feasibility and versatility of the proposed slicing method based on a rotary 3D printer.
Originality/value
This paper provides a novel and feasible slicing method for multi-axis rotary 3D printers, making manufacturing thin-wall and complex parts possible. To further broaden the proposed slicing method’s application in further research, adaptive tool path generation for flat and curved layer printing could be applied with a combination of flat and curved layers in the same layer, different layers or even different parts of structures.
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Burçak Zehir, Mirsadegh Seyedzavvar and Cem Boğa
This study aims to comprehensively investigate the mixed-mode fracture behavior and mechanical properties of selective laser sintering (SLS) polyamide 12 (PA12) components…
Abstract
Purpose
This study aims to comprehensively investigate the mixed-mode fracture behavior and mechanical properties of selective laser sintering (SLS) polyamide 12 (PA12) components, considering different build orientations and layer thicknesses. The primary objectives include the following. Conducting mixed-mode fracture and mechanical analyses on SLS PA12 parts. Investigating the influence of build orientation and layer thickness on the mechanical properties of SLS-printed components. Examining the fracture mechanisms of SLS-produced Arcan fracture and tensile specimens through experimental methods and finite element analyses.
Design/methodology/approach
The research used a combination of experimental techniques and numerical analyses. Tensile and Arcan fracture specimens were fabricated using the SLS process with varying build orientations (X, X–Y, Z) and layer thicknesses (0.1 mm, 0.2 mm). Mechanical properties, including tensile strength, modulus of elasticity and critical stress intensity factor, were quantified through experimental testing. Mixed-mode fracture tests were conducted using a specialized fixture, and finite element analyses using the J-integral method were performed to calculate fracture toughness. Scanning electron microscopy (SEM) was used for detailed morphological analysis of fractured surfaces.
Findings
The investigation revealed that the highest tensile properties were achieved in samples fabricated horizontally in the X orientation with a layer thickness of 0.1 mm. Additionally, parts manufactured with a layer thickness of 0.2 mm exhibited favorable mixed-mode fracture behavior. The results emphasize the significance of build orientation and layer thickness in influencing mechanical properties and fracture behavior. SEM analysis provided valuable insights into the failure mechanisms of SLS-produced PA12 components.
Originality/value
This study contributes to the field of additive manufacturing by providing a comprehensive analysis of the mixed-mode fracture behavior and mechanical properties of SLS-produced PA12 components. The investigation offers novel insights into the influence of build orientation and layer thickness on the performance of such components. The combination of experimental testing, numerical analyses and SEM morphological observations enhances the understanding of fracture behavior in additive manufacturing processes. The findings contribute to optimizing the design and manufacturing of high-quality PA12 components using SLS technology.
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Fernando Peña, José Carlos Rico, Pablo Zapico, Gonzalo Valiño and Sabino Mateos
The purpose of this paper is to provide a new procedure for in-plane compensation of geometric errors that often appear in the layers deposited by an additive manufacturing (AM…
Abstract
Purpose
The purpose of this paper is to provide a new procedure for in-plane compensation of geometric errors that often appear in the layers deposited by an additive manufacturing (AM) process when building a part, regardless of the complexity of the layer geometry.
Design/methodology/approach
The procedure is based on comparing the real layer contours to the nominal ones extracted from the STL model of the part. Considering alignment and form deviations, the compensation algorithm generates new compensated contours that match the nominal ones as closely as possible. To assess the compensation effectiveness, two case studies were analysed. In the first case, the parts were not manufactured, but the distortions were simulated using a predictive model. In the second example, the test part was actually manufactured, and the distortions were measured on a coordinate measuring machine.
Findings
The geometric deviations detected in both case studies, as evaluated by various quality indicators, reduced significantly after applying the compensation procedure, meaning that the compensated and nominal contours were better matched both in shape and size.
Research limitations/implications
Although large contours showed deviations close to zero, dimensional overcompensation was observed when applied to small contours. The compensation procedure could be enhanced if the applied compensation factor took into account the contour size of the analysed layer and other geometric parameters that could have an influence.
Originality/value
The presented method of compensation is applicable to layers of any shape obtained in any AM process.
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Josué Costa-Baptista, Edith Roland Fotsing, Jacky Mardjono, Daniel Therriault and Annie Ross
The purpose of this paper is the design and experimental investigation of compact hybrid sound-absorbing materials presenting low-frequency and broadband sound absorption.
Abstract
Purpose
The purpose of this paper is the design and experimental investigation of compact hybrid sound-absorbing materials presenting low-frequency and broadband sound absorption.
Design/methodology/approach
The hybrid materials combine microchannels and helical tubes. Microchannels provide broadband sound absorption in the middle frequency range. Helical tubes provide low-frequency absorption. Optimal configurations of microchannels are used and analytical equations are developed to guide the design of the helical tubes. Nine hybrid materials with 30 mm thickness are produced via additive manufacturing. They are combinations of one-, two- and four-layer microchannels and helical tubes with 110, 151 and 250 mm length. The sound absorption coefficient of the hybrid materials is measured using an impedance tube.
Findings
The type of microchannels (i.e. one, two or four layers), the number of rotations and the number of tubes are key parameters affecting the acoustic performance. For instance, in the 500 Hz octave band (α500), sound absorption of a 30 mm thick hybrid material can reach 0.52 which is 5.7 times higher than the α500 of a typical periodic porous material with the same thickness. Moreover, the broadband sound absorption for mid-frequencies is reasonably high with and α1000 > 0.7. The ratio of first absorption peak wavelength to structure thickness λ/T can reach 17, which is characteristic of deep-subwavelength behaviour.
Originality/value
The concept and experimental validation of a compact hybrid material combining a periodic porous structure such as microchannels and long helical tubes are original. The ability to increase low-frequency sound absorption at constant depth is an asset for applications where volume and weight are constraints.
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Rodrigo Enzo de Prada, Guillermo Rubén Bossio and Mariano Martín Bruno
The purpose of this study is to investigate how the amount of material used and printing parameters affect the mechanical and water sorption properties of acrylonitrile butadiene…
Abstract
Purpose
The purpose of this study is to investigate how the amount of material used and printing parameters affect the mechanical and water sorption properties of acrylonitrile butadiene styrene printed parts.
Design/methodology/approach
The specimens were printed using different printing parameters such as shell number, infill pattern and printing orientation, while accounting for the amount of material used. The mechanical properties of the printed parts were then evaluated using tensile, compression and flexural tests, along with sorption tests.
Findings
The results revealed that the maximum tensile stress of 31.41 MPa was obtained when using 100% infill and a horizontal printing orientation. Similarly, the maximum flexural strength and compression of 40.5 MPa and 100.7 MPa, respectively, were obtained with 100% infill. The printing orientation was found to have a greater impact on mechanical behavior compared to the number of shells or infill patterns. Specifically, the horizontal printing orientation resulted in specimens with at least 25% greater strength compared to the vertical printing orientation. Furthermore, the relationship between the amount of material used and strength was evident in the tensile and flexural tests, which showed a close correlation between the two.
Originality/value
This study’s originality lies in its focus on optimizing the amount of material used to achieve the best strength-to-mass ratio and negligible water infiltration. The findings showed that specimens with two shells and a 60% infill density exhibited the best strength-to-mass ratio.
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Fatih Yılmaz, Ercan Gürses and Melin Şahin
This study aims to evaluate and assess the elastoplastic properties of Ti-6Al-4V alloy manufactured by Arcam Q20 Plus electron beam melting (EBM) machine by a tensile test…
Abstract
Purpose
This study aims to evaluate and assess the elastoplastic properties of Ti-6Al-4V alloy manufactured by Arcam Q20 Plus electron beam melting (EBM) machine by a tensile test campaign and micro computerized tomography (microCT) imaging.
Design/methodology/approach
ASTM E8 tensile test specimens are designed and manufactured by EBM at an Arcam Q20 Plus machine. Surface quality is improved by machining to discard the effect of surface roughness. After surface machining, hot isostatic pressing (HIP) post-treatment is applied to half of the specimens to remove unsolicited internal defects. ASTM E8 tensile test campaign is carried out simultaneously with digital image correlation to acquire strain data for each sample. Finally, build direction and HIP post-treatment dependencies of elastoplastic properties are analyzed by F-test and t-test statistical analyses methods.
Findings
Modulus of elasticity presents isotropic behavior for each build direction according to F-test and t-test analysis. Yield and ultimate strengths vary according to build direction and post-treatment. Stiffness and strength properties are superior to conventional Ti-6Al-4V material; however, ductility turns out to be poor for aerospace structures compared to conventional Ti-6Al-4V alloy. In addition, micro CT images show that support structure leads to dense internal defects and pores at applied surfaces. However, HIP post-treatment diminishes those internal defects and pores thoroughly.
Originality/value
As a novel scientific contribution, this study investigates the effects of three orthogonal build directions on elastoplastic properties, while many studies focus on only two-build directions. Evaluation of Poisson’s ratio is the other originality of this study. Furthermore, another finding through micro CT imaging is that temporary support structures result in intense defects closer to applied surfaces; hence high-stress regions of structures should be avoided to use support structures.
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Mohd Javaid, Shahbaz Khan, Abid Haleem and Shanay Rab
Modern technologies are seen as an essential component of the fourth industrial revolution (industry 4.0) and their adoption is vital to transform the existing manufacturing…
Abstract
Purpose
Modern technologies are seen as an essential component of the fourth industrial revolution (industry 4.0) and their adoption is vital to transform the existing manufacturing system into industry 4.0-based manufacturing system. Therefore, the primary objective of this research explores the barriers of modern technology adoption and their mitigating solutions in order to align with Industry 4.0 objectives.
Design/methodology/approach
Barriers to adopting modern technologies and respective mitigating solutions are identified from the available literature. Further, these barriers are ranked with the help of expert opinions by using the BWM method appropriately. The identified solutions are ranked using the combined compromise solution (CoCoSo) method.
Findings
Several modern technologies and their capabilities are recognised to support the industry 4.0-based manufacturing systems. This study identifies 22 barriers to the effective adoption of modern technologies in manufacturing and 14 solutions to overcome these barriers. Change management, the high initial cost of technology and appropriate support infrastructure are the most significant barriers. The most prominent solutions to overcome the most considerable barriers are ‘supportive research, development and commercialisation environment’, ‘updated policy and effective implementation’ and ‘capacity building through training’ that are the top three solutions that need to be addressed.
Research limitations/implications
The barriers and solutions of modern technology adoption are obtained through a comprehensive literature review, so there is a chance to ignore some significant barriers and their solutions. Furthermore, ranking barriers and solutions is done with expert opinion, which is not free from biases.
Practical implications
This identification and prioritisation of barriers will help managers to understand the barriers so they can better prepare themselves. Furthermore, the suggested solutions to overcome these barriers are helpful for the managers and could be strategically adopted through optimal resource utilisation.
Originality/value
This study proposes a framework to identify and analyse the significant barriers and solutions to adopting modern technologies in the manufacturing system. It might be helpful for manufacturing organisations that are willing to transform their manufacturing system into industry 4.0.
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Iván La Fé-Perdomo, Jorge Andres Ramos-Grez, Ramón Quiza, Ignacio Jeria and Carolina Guerra
316 L stainless steel alloy is potentially the most used material in the selective laser melting (SLM) process because of its versatility and broad fields of applications (e.g…
Abstract
Purpose
316 L stainless steel alloy is potentially the most used material in the selective laser melting (SLM) process because of its versatility and broad fields of applications (e.g. medical devices, tooling, automotive, etc.). That is why producing fully functional parts through optimal printing configuration is still a key issue to be addressed. This paper aims to present an entirely new framework for simultaneously reducing surface roughness (SR) while increasing the material processing rate in the SLM process of 316L stainless steel, keeping fundamental mechanical properties within their allowable range.
Design/methodology/approach
Considering the nonlinear relationship between the printing parameters and features analyzed in the entire experimental space, machine learning and statistical modeling methods were defined to describe the behavior of the selected variables in the as-built conditions. First, the Box–Behnken design was adopted and corresponding experimental planning was conducted to measure the required variables. Second, the relationship between the laser power, scanning speed, hatch distance, layer thickness and selected responses was modeled using empirical methods. Subsequently, three heuristic algorithms (nonsorting genetic algorithm, multi-objective particle swarm optimization and cross-entropy method) were used and compared to search for the Pareto solutions of the formulated multi-objective problem.
Findings
A minimum SR value of approximately 12.83 μm and a maximum material processing rate of 2.35 mm3/s were achieved. Finally, some verification experiments recommended by the decision-making system implemented strongly confirmed the reliability of the proposed optimization methodology by providing the ultimate part qualities and their mechanical properties nearly identical to those defined in the literature, with only approximately 10% of error at the maximum.
Originality/value
To the best of the authors’ knowledge, this is the first study dealing with an entirely different and more comprehensive approach for optimizing the 316 L SLM process, embedding it in a unique framework of mechanical and surface properties and material processing rate.
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Erwin Molino Alvarez, Sergio Andres Quintana González, Luis Lisandro Lopez Taborda and Enrique Esteban Niebles Nuñez
Additive manufacturing has disadvantages, such as the maximum part size being limited by the machine’s working volume. Therefore, if a part more considerable than the working…
Abstract
Purpose
Additive manufacturing has disadvantages, such as the maximum part size being limited by the machine’s working volume. Therefore, if a part more considerable than the working volume is required, the part is produced in parts and joined together. Among the many methods of joining thermoplastic parts, adhesives and mechanical interlocking are considered. This study aims to characterize and optimize mechanically stressed adhesive joints combined with female and male mechanical interlocking on acrylonitrile butadiene styrene (ABS) specimens made with fused filament fabrication (FFF) so that the joint strength is as close as possible to the strength of the base material.
Design/methodology/approach
This study characterized the subject’s state of the art to justify the decisions regarding the experimental design planned in this research. Subsequently, this study designed, executed and analyzed the experiment using a statistical analysis of variance. The output variables were yield strength and tensile strength. The input variables were two different cyanoacrylate adhesives, two different types of mechanical interlock (truncated pyramid and cylindrical pin) and the dimensions of each type of mechanical interlock. This study used simple and factorial experiments to select the best adhesive and interlocking to be optimized using the response surface and the steep ascent method.
Findings
The two adhesives have no statistical difference, but they show different data dispersion. The design or yield stress was a determining factor for selecting the optimal specimen, with cylindrical geometry exhibiting higher resistance at initial failure. Geometry type is crucial due to the presence of stress concentrators. The cylindrical geometry with fewer stress concentrators demonstrated better tensile strength. Ultimately, the specimen with a mechanically reinforced joint featuring a cylindrical pin of radius 5.45 mm and height of 4.6 mm exhibited the maximum tensile and yield strength.
Originality/value
Previous research suggests that a research opportunity is the combination of bonding methods in FFF or fused deposition modeling, which is not a frequent topic, and this research to enrich that topic combines the adhesive with mechanically interlocked joints and studies it experimentally for FFF materials, to provide unpublished information of the performance of the adhesive joint with mechanical interlocking, to designers and manufacturers of this technology.
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Soud Mohammad Almahamid, Nehal Almurbati, Adel Ismail Al-Alawi and Mohammed Al Fataih
The study aims to develop an integrated model for three-dimensional (3D) printing adoption in the Gulf Cooperation Council (GCC) context to form a baseline for more theoretical…
Abstract
Purpose
The study aims to develop an integrated model for three-dimensional (3D) printing adoption in the Gulf Cooperation Council (GCC) context to form a baseline for more theoretical and empirical debate from emerging markets.
Design/methodology/approach
A qualitative approach with a convenience sample is adopted since there is no formal body that has accurate data about the number of companies, governmental bodies, nongovernmental organizations, universities, labs, etc. that already have adopted 3D printing.
Findings
The results indicate that the technological usefulness of 3D printing and its ease-of-use factor were found to be lacking among community members and governmental officials. Yet, these factors were the most influential factor affecting the spread of 3D printing technology adoption in the GCC countries. Nevertheless, the adaptation of 3D printing is not yet at the level of its global markets, nor is it used within leading companies’ assembly lines. In addition, the 3D printing awareness and use increased during the COVID-19 pandemic. Yet, the adaptation rate is still below expectations due to several challenges that face the growth of the 3D printing market in the GCC countries. The most vital challenge facing 3D printing growth is manifested in governmental policies and regulations.
Practical implications
Companies’ managers can benefit from the current study results by focusing on the factors that facilitate 3D adoption and avoiding bottle-neck factors that hinder the speed of the 3D adoption. 3D providers can also benefit by understanding the factors that affect 3D adoption and designing their machine and marketing strategy in a way that helps the intended companies to easily adopt 3D printing.
Originality/value
To the best of the authors’ knowledge, this is the first study that explored 3D printing adoption on the GCC countries’ level. It also adds a new flavor to the literature by exploring 3D adoption during the COVID-19 crisis.
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