FDM Method Research Articles

An experimental investigation on mechanical performances of 3D printed lightweight ABS pipes with different cellular wall thickness

In recent years, cellular structures have attracted great deal of attention of many researchers due to their unique properties like exhibiting high strength at low density and great energy absorption. Also, the applications of cellular structures (or lattice structures) such as wing airfoil, tire, fiber and implant, are mainly used in aerospace, automotive, textile and biomedical industries respectively. In this investigation, the idea of using cellular structures in pipes made of acrylonitrile butadiene styrene (ABS) material was focused on and four different pipe types were designed as honeycomb structure model, straight rib pattern model, hybrid version of the first two models and fully solid model. Subsequently, these models were 3D printed by using FDM method and these lightweight pipes were subjected to compression tests in order to obtain stress-strain curves of these structures. Mechanical properties of lightweight pipes like elasticity modulus, specific modulus, compressive strength, specific compressive strength, absorbed energy and specific absorbed energy were calculated and compared to each other. Moreover, deformation modes were recorded during all compression tests and reported as well. The results showed that pipe models including lattice wall thickness could be preferred for the applications which don’t require too high compressive strength and their specific energy absorption values were notably capable to compete with fully solid pipe structures. In particular, rib shape lattice structure had the highest elongation while the fully solid one possessed worst ductility. Lastly, it is pointed out that 3D printing method provides a great opportunity to have a foresight about production of uncommon parts by prototyping.

Design and Production of Smart Wearable Textile Products Using Layered Manufacturing Technology with Photovoltaic Energy

Smart textiles are used in a wide range of areas, such as defense industry, security, medicine, health, aviation, space sciences, environment, energy, biotechnology, agriculture, food, cosmetics and fashion design. In this study, with the progress of technology in the area of the wearable smart textile industry, 3D manufacturing which has started to take place in the industry as a new manufacturing method or in other words layered manufacturing practices are discessed. For this purpose, a solar panel was placed in the 3D printed material obtained by FDM method, one of the layered manufacturing methods, and integrated into the textile material and to charge our electronic devices from photovoltaic energy was explained. It is aimed to produce, using the knowledge gained as a result of the study, smart textile products that facilitate human life with 3D printed materials obtained from filaments with conductive additive.

Methodology for the Quality Control Process of Additive Manufacturing Products Made of Polymer Materials

The objective of this publication is to present a quality control methodology for additive manufacturing products made of polymer materials, where the methodology varies depending on the intended use. The models presented in this paper are divided into those that are manufactured for the purpose of visual presentation and those that directly serve the needs of the manufacturing process. The authors also a propose a comprehensive control system for the additive manufacturing process to meet the needs of Industry 4.0. Depending on the intended use of the models, the quality control process is divided into three stages: data control, manufacturing control, and post-processing control. Research models were made from the following materials: RGD 720 photopolymer resin (PolyJet method), ABS M30 thermoplastic (FDM method), E-Partial photopolymer resin (DLP method), PLA thermoplastic (FFF method), and ABS thermoplastic (MEM method). The applied measuring tools had an accuracy of at least an order of magnitude higher than that of the manufacturing technologies used. The results show that the PolyJet method is the most accurate, and the MEM method is the least accurate. The findings also confirm that the selection of materials, 3D printing methods, and measurement methods should always account not only for the specificity and purpose of the model but also for economic aspects, as not all products require high accuracy and durability.

ESTIMATION OF TRIBOLOGICAL PROPERTIES OF SELECTED PLASTICS MATERIALS MANUFACTURED BY EXTRUSION AND 3D PRINTING

The following work presents the results of research about the assessment of tribological properties of plastics used as components in modes of transport. For this purpose, the wear resistance of materials used in 3D printing (PA6CF and ABS), and extrusion moulding (PA) were tested. The tribological research was carried out with the use of the T-05 tester in the roller-block system. The samples in the form of cuboids with a concave rounding of one wall were made on a 3D printer using the FDM method. The counter-sample was a ring made of aluminium alloy subjected to anodizing. The research was carried out under a variable loads, in reciprocating motion, under dry friction conditions. After that the tribological characteristics were assessed. The research and analysis of the results confirmed the possibility of using selected plastics in modes of transport.

FEM analysis of 3D lattice structures of ABS material

FDM is a typical additive manufacturing method. Since FDM is a method of stacking layers one by one, it generally has a flat lattice structure. In this study, by checking the distribution of stress and deformation for several lattice structures made of ABS material, it is intended to find a structure with better mechanical properties with less material. Several three-dimensional lattice structures are modeled using parametric modeling. Subsequently, a constant pressure is applied to the same area to check the stress and strain distribution. A structure with a low maximum stress value in the stress concentration region and a small amount of deformation will have the best mechanical properties. To do this, parametric modeling is performed using Inventor to model four three-dimensional lattice structures. Afterwards, use Ansys Workbench to check the stress and deformation distribution. Looking at the stress distribution, stress concentration occurred in the truss supporting the upper surface of the SC structure. In the BCC and PTC structures, stress concentration occurred at the point where the upper surface and the truss met. In the FCC structure, it can be seen that the load is distributed throughout the truss structure. Looking at the deformation distribution, both the SC and BCC structures show similar amounts of deformation. It was confirmed that the FCC structure had less maximum deformation than the PTC structure with the thickest truss. Unlike previous studies, it was confirmed that the higher the internal filling rate, the better the mechanical properties may not come out. The FDM method can obtain different mechanical properties depending on the internal lattice structure as well as the internal filling rate. In a later study, we will find a new calculation algorithm that applies variables by FDM characteristics using the data obtained by printing the actual specimen.

Extrusion-Based 3D Printing Applications of PLA Composites: A Review

Polylactic acid (PLA) is the most widely used raw material in extrusion-based three-dimensional (3D) printing (fused deposition modeling, FDM approach) in many areas since it is biodegradable and environmentally friendly, however its utilization is limited due to some of its disadvantages such as mechanical weakness, water solubility rate, etc. FDM is a simple and more cost-effective fabrication process compared to other 3D printing techniques. Unfortunately, there are deficiencies of the FDM approach, such as mechanical weakness of the FDM parts compared to the parts produced by the conventional injection and compression molding methods. Preparation of PLA composites with suitable additives is the most useful technique to improve the properties of the 3D-printed PLA parts obtained by the FDM method. In the last decade, newly developed PLA composites find large usage areas both in academic and industrial circles. This review focuses on the chemistry and properties of pure PLA and also the preparation methods of the PLA composites which will be used as a raw material in 3D printers. The main drawbacks of the pure PLA filaments and the necessity for the preparation of PLA composites which will be employed in the FDM-based 3D printing applications is also discussed in the first part. The current methods to obtain PLA composites as raw materials to be used as filaments in the extrusion-based 3D printing are given in the second part. The applications of the novel PLA composites by utilizing the FDM-based 3D printing technology in the fields of biomedical, tissue engineering, human bone repair, antibacterial, bioprinting, electrical conductivity, electromagnetic, sensor, battery, automotive, aviation, four-dimensional (4D) printing, smart textile, environmental, and luminescence applications are presented and critically discussed in the third part of this review.

Improving bioactivity and strength of PEEK composite polymer for bone application

Poly-Ether-Ketone (PEEK) is a bioactive material capable of replacing traditional metal and ceramic components in biomedical applications but still lacks some strength and biological propertices compared with natural bone. In this research, calcium hydroxyapatite (cHAp) and reduced Graphene oxide (rGO) were combined with PEEK, and different lattice porose structures were produced to improve interfaces biocompatibility and mimick the bone. The FDM method was used to obtain PEEK, and rGOcHAP composites were coated, and Finite Element Analysis (FEA) was used to simulate the different lattice conditions of varying ratio. The new PEEK/rGO/cHAP composite characterisation was obtained by SEM analysis and the mechanical strength via compressive and tensile test. The composite with the highest proportion of rGO of 5% shows more biocompatibility and mechanical strength. The Young modulus and bulk modulus of PEEK increase exponentially with the increase of rGOcHAP from 3.85Gpa to 54.965% of 5 wt% addition of rGO. Also, PEEK/rGo/cHAp induces cell formation after several days of immersion in body fluids simulated with Dulbecco's Modified Eagle Medium (DMEM) and Nutrient Agar Solution (NAS) to determine their biological bioactivity. The In vivo experiments showed that cell aggregation and biological activity around PEEK/rGO/cHAP composite were higher than PEEK and the NAS shows more cell growth and bioactivity than DMEM.

ИССЛЕДОВАНИЕ ПОРИСТОСТИ КОМПОЗИТНЫХ КОНСТРУКЦИЙ НА ОСНОВЕ 3D-ПЕЧАТНЫХ КАРКАСОВ, ПРОПИТАННЫХ ЭПОКСИДНОЙ СМОЛОЙ

In the designs of modern machines, more and more polymer parts are used, at the same time, there is a problem of their quick replacement in case of failure. Reducing the cost and repair time can be achieved by using 3D printing by FDM method, but such parts do not always demonstrate the necessary strength. To improve their mechanical properties, a method of their impregnation after printing in epoxy resins was previously proposed. (Research purpose) The research purpose is in studying the dependence of the porosity of composite structures based on 3D-printed frames impregnated with resin on the parameters of their manufacture. (Materials and methods) Authors used samples for the first stage of the work, which are 3D-printed cylinders with different wall thicknesses and internal geometries, impregnated with ED-20 epoxy resin. The samples were cut in several sections and the number of pores in these sections was calculated. The second stage of the experiment was to evaluate the porosity of a part of complex geometry. (Results and discussion) With an increase in the percentage of filling and thickening of the wall in 3D printing, there is a tendency to reduce the number of pores. With a less dense filling of the frame and a thinner wall, the resin is worse retained in the product and partially flows out after impregnation. The best filling of a part of a complex shape was observed when it was cured in the position of the massive part up. (Conclusions) For the production of high- quality composite parts based on 3D-printed frames impregnated with epoxy resin, it is recommended to choose the largest possible percentage of filling during 3D printing and strive to position the part during the curing process after impregnation with the massive part up.

ИССЛЕДОВАНИЕ ПОРИСТОСТИ КОМПОЗИТНЫХ КОНСТРУКЦИЙ НА ОСНОВЕ 3D-ПЕЧАТНЫХ КАРКАСОВ, ПРОПИТАННЫХ ЭПОКСИДНОЙ СМОЛОЙ

In the designs of modern machines, more and more polymer parts are used, at the same time, there is a problem of their quick replacement in case of failure. Reducing the cost and repair time can be achieved by using 3D printing by FDM method, but such parts do not always demonstrate the necessary strength. To improve their mechanical properties, a method of their impregnation after printing in epoxy resins was previously proposed. (Research purpose) The research purpose is in studying the dependence of the porosity of composite structures based on 3D-printed frames impregnated with resin on the parameters of their manufacture. (Materials and methods) Authors used samples for the first stage of the work, which are 3D-printed cylinders with different wall thicknesses and internal geometries, impregnated with ED-20 epoxy resin. The samples were cut in several sections and the number of pores in these sections was calculated. The second stage of the experiment was to evaluate the porosity of a part of complex geometry. (Results and discussion) With an increase in the percentage of filling and thickening of the wall in 3D printing, there is a tendency to reduce the number of pores. With a less dense filling of the frame and a thinner wall, the resin is worse retained in the product and partially flows out after impregnation. The best filling of a part of a complex shape was observed when it was cured in the position of the massive part up. (Conclusions) For the production of high-quality composite parts based on 3D-printed frames impregnated with epoxy resin, it is recommended to choose the largest possible percentage of filling during 3D printing and strive to position the part during the curing process after impregnation with the massive part up.

Topological Optimization of a Component Made by the FDM Method

Topological Optimization of a Component Made by the FDM Method

Analysis The Effect Of Internal Geometry On The Mechanical Properties Of Acrylonitril Butadiene Styrene (ABS) Materials Prepared Using 3D Printing

The process of research and refinement of Fused Deposition Modeling 3D Printer, surely contains many variables and parameters with the aim of generating a 3D object with the results and the level of accuracy approaching its original design and can be applied as the expected design. In addition to the effect of printer type on the FDM method, the filament material used as a filler to print 3D objects certainly has different mechanical and physical characteristics, thus allowing for different object results for each different filament material. This research was conducted to determine the effect of internal variations of its geometry and dimensions on the mechanical properties of ABS using a 3D Printer. The internal geometries that are varied are triangle and honeycomb, with variations in thickness for each geometry are 1 mm and 2 mm, and variations in the axis of symmetry are 4.5 mm and 9 mm. The results showed that the control sample had tensile and bending strength results that matched the ABS filament datasheet reference. Objects with an internal geometry triangle in the size 4.5 mm and 2 mm of thickness have better tensile and bending strength than honeycomb geometry.

The Study of Physico-Mechanical Properties of Polylactide Composites with Different Level of Infill Produced by the FDM Method.

The aim of this study was to evaluate the changes in physical-mechanical properties of the samples manufactured by 3D printing technology with the addition of varying degrees of polylactide (PLA) infill (50, 70, 85 and 100%). Half of the samples were soaked in physiological saline. The material used for the study was neat PLA, which was examined in terms of hydrolytic degradation, crystallization, mechanical strength, variability of properties at elevated temperatures, and dissipation of mechanical energy depending on the performed treatment. A significant impact of the amount of infill on changeable mechanical properties, such as hydrolytic degradation and crystallization was observed. The FDM printing method allows for waste–free production of light weight unit products with constant specyfic strength.

Tailoring physico-mechanical properties and rheological behavior of ABS filaments for FDM via blending with SEBS TPE

PurposeThis paper aims to focus on the development of the three-dimensional (3D) printing filaments based on acrylonitrile butadiene styrene (ABS) copolymer and styrene-ethylene/butylene-styrene (SEBS) block copolymer, with tailored viscoelastic properties and controlled flow during the 3D printing process.Design/methodology/approachIn this investigation, ABS was blended with various amounts of SEBS via a melt mixing process. Then the ABS/SEBS filaments were prepared by a single-screw extruder and printed by the FDM method. The rheological properties were determined using an MCR 501 from Anton-Paar. The melt flow behavior of ABS/SEBS filaments was determined. The morphology of the filaments was studied by scanning electron microscope and the mechanical (tensile and impact) properties, surface roughness and void content of printed samples were investigated.FindingsThe rheological results can accurately interpret what drives the morphology and mechanical properties’ changes in the blends. The impact strength, toughness, elongation-at-break and anisotropy in mechanical properties of ABS samples were improved concurrently by adding 40 Wt.% of SEBS. The optimal tensile properties of blend containing 40 Wt.% SEBS samples were obtained at −45°/+45° raster angle, 0.05 mm layer thickness and XYZ build orientation. Optimized samples showed an 890% increase in elongation compared to neat ABS. Also, the impact strength of ABS samples showed a 60% improvement by adding 40 Wt.% SEBS.Originality/valueThe paper simultaneously evaluates the effects of material composition and 3D printing parameters (layer thickness, raster angle and build orientation) on the rheology, morphology, mechanical properties and surface roughness. Also, a mechanical properties comparison between printed samples and their compression-molded counterpart was conducted.

Glass-Filled Composite Materials Based on Polyarylene Ether Sulfones

This article provides a literature overview of glass-filled polyarylene sulfones. The main properties of polyarylene ether sulfones and applications are given. The industrially produced brands of glass-filled composites and their properties are shown. A problem of low interfacial interaction between polymer and fiberglass and the ways to increase was considered. Also the results of development of glass-filled composites based on polyphenylene sulfone for using in additive technologies, in particular 3D-printing by FDM method are shown.

Literature review on emissions from additive manufacturing by FDM method and their impact on human health

Literature review on emissions from additive manufacturing by FDM method and their impact on human health

A VERIFICATION ANALYSIS FOR PILES IN LIQUEFIABLE SOIL

The soil loses its strength and behaves like a liquid when the increasing the pore water pressure under dynamic loads in saturated sandy soils. The large soil displacements can occur on liquefied soils. Pile foundations are applied to bearing capacity problems soil which may be subjected to large lateral displacements due to liquefaction. Although there are many theoretical and practical studies on the behavior of laterally loaded piles in liquefiable soils, there is still no definitive method. The pile damages which are occurred by lateral spreading resulting from liquefaction under dynamic loads have been investigated by many scientists and studies on the causes of damages have increased. Pile response in liquefiable soils and the evaluation of its possible damage are generally assessed by using some available numerical method, for example: finite difference (FDM), finite element (FEM) and boundary element (BEM) methods. In this paper, the FDM method is used to study the pile behavior in liquefiable soils and its reliability is checked by comparison with centrifuge test results from literature. It, in which the effect of liquefaction-induced lateral spreading on pile was evaluated, are also studied. Finally, the analysis results with FLAC 2D are compared with those observed in a centrifuge experiment.

Functional fillers in composite filaments for fused filament fabrication; a review

Fused Deposition Modelling (FDM or Fused Filament Fabrication, FFF) constitutes the most widespread 3D printing technology because it uniquely combines simplicity, cost and speed. One of the major drawbacks of this promising technology that hinders its applicability to various industrial fields constitutes the lack of variation of feedstock materials in filament form, that are restricted to common thermoplastic polymers. Many industrial fields set their own specification to the materials that are used in terms of their physical, mechanical, thermal and electrical properties, and the applicability of FDM method to such fields requires the development of new filaments with corresponding properties. For this purpose, last two decades several studies have been held aiming to investigate the development of new composite filaments with enhanced or just different properties in comparison to the parental thermoplastics, through the incorporation of functional fillers of various types. In the current article, a review of the State of the Art in that field is presented. Functional fillers of different types have been considered and categorized (ceramic, C-based, minerals, metallic, glassy and wood), the composite filaments production methods are presented and the reported impact of fillers in attained composite filaments properties and morphology are given. Finally, an informative table is provided where neat thermoplastic and composite filaments’ properties are compared, scoping to reveal the provided functionality of each filler.

Additive manufacturing and biomechanical validation of a patient‐specific diabetic insole

Centers for Disease Control and Prevention (CDC) has reported that lower extremity amputation (LEA) rate of per 1000 diabetic patients is 18.4 because of the complications that first appeared in the foot. A second amputation is also required for 9% to 17% of these patients within the same year although LEA may be preventable. Most of the diabetic foot conditions may be prevented and treated by a therapeutic footwear or a medical device such as an insole or an orthotic shoe. Traditional insole manufacturing is a laborious work that requires specific skills. Moreover, traditional approaches contain harmful material particles that may cause respiratory failure. Unfortunately, manufactured insoles may not be suitable for any mass‐produced footwear in all cases. Therefore, patient requires to get insole‐specific footwear. In this study, a diabetic insole was manufactured by means of a fused deposition modeling‐(FDM) based system and a thermoplastic polymer. Biomechanical functionality was determined according to the applied polymer analysis on each produced sample and foam material. Subsequently, finite element analysis (FEA) was performed to target insole geometry to ensure the quality of the final medical product. Additive and traditional manufactured insoles are compared according to the cost and function. As a result, fabrication of an insole, based on the FDM method, was improved down to 8 h and 9 m. The weight of an insole prototype was 74.74 g, and the material cost was $3.44 while total cost of the traditional foam casting was determined as $35.37 and weight of the insole was 72.6 g for this study. Consequently, benefits of the applied method are evaluated.

Geometric accuracy of rapid prototyping technologies using laser scanner and coordinate measurement machine

In this paper we present a prototyping method used in medical data. 3D printing technology is extremely important, especially in medical area. Using 3D printing in preoperative treatment planning seems to be a proper solution in personalized medicine, contributing to improving healthcare system quality. Medical measurements methods on living bones, with respect to their natural environment are still unknown, the basic research includes mainly the measurement of landmarks using a digital caliper, where the linear measurement is taken between the marked points. Another way is to use a coordinate measuring machine. Most often, the accuracy measurement methods are based on marking landmarks on the object, which are collected by a machine, and then performs coordinate measurements of points. In our research we focus not on individual points of the model but on the measurement of whole objects, we prepared materials, and printed the model in 3D technology in different technologies and on different devices: FDM, PJ, SLM. On the basis of our work we conclude there is no best RP technique for making medical models. Due to the criterion of model accuracy, PolyJet is one of the most suitable technologies for medical modelling. The CJP method is the most appropriate for the cost of making a model. Due to the type of material the FDM method is the most suitable for medical applications. 3D printing technologies provide physicians, engineers and scientists with the ability to create customized solutions for a variety of conditions.

Numerical study on the CRLD cable–rock interaction under static pull-out loading using coupled DEM–FDM method

As an effective energy-absorbing cable, constant resistance large deformation (CRLD) cables have been widely applied in rock engineering projects; however, to the best of our knowledge, its interaction mechanism with the surrounding rock has never been studied. According to previous practical projects, the CRLD cable–rock interaction differs from that of conventional cables because of the tubular expansion during the CRLD process, and it influences the performance of the cable reinforcement system. Therefore, an attempt was made to investigate the characteristics of the CRLD cable–rock interaction under static pull-out loading by using a coupled numerical method. The structure of the CRLD cable was modelled via the finite-difference method, and the surrounding rock was modelled via the discrete-element method. The micro-parameters of the surrounding rock were carefully calibrated, and the macro-parameters of the CRLD cable were verified by comparing them with a corresponding experimental test in the laboratory. The numerical results were carefully analysed. The constant resistance forces of a single CRLD cable and a CRLD cable reinforcement system were compared. The distribution of the normal and shearing stresses on the cable–rock interface was obtained, and the evolution mode of the pull-out strength was examined. In addition, the failure mode of the grouting material and surrounding rock was studied on a micro-scale. The findings describe the interaction of the CRLD cable against the surrounding rock, reveal its special anchorage mechanism, and can be used to predict and improve the performance of the CRLD cable reinforcement system.