CC BY
9
SRSTI 55.24.99
https://doi.org/10.48081/MFBQ8991
*A. Rakishev1, B. Donenbayev2, K. R. Jamaludin3
1,2Abylkas Saginov Karaganda Technical University,
Republic of Kazakhstan, Karaganda;
3Universiti Teknologi Malaysia, Malaysia, Kuala Lumpur;
*e-mail: a.rakishev@kstu.kz
STUDY OF THE MECHANICAL CHARACTERISTICS OF FDM
(3D PRINTED) PARTS: EMPIRICAL AND COMPUTATIONAL METHODS
Fused deposition modelling, alternatively referred to as Fused Filament
Fabrication, is an additive manufacturing technique that has garnered significant
attention across various industries due to its diverse applications. This research
investigates the ultimate tensile strength and elastic modulus of 3D-printed Polylactic
acid samples, following the ISO-527-2-2012 standard. The mechanical performance
of the created parts is considered from both experimental and computational points
of view. The finite element method within the ANSYS environment was employed for
computer-based load and strength calculations.
Tensile specimens are fabricated using the Fused deposition modelling approach.
The experimental outcomes were utilised to derive all the essential engineering constants
required for evaluating the mechanical behaviour. The validity of the theoretical model
has been confirmed through a comprehensive comparison with a substantial volume of
experimental data, exhibiting mean errors of approximately 1 %.
The objective of this research is to assess the effectiveness and efficacy
of analytical models in predicting the structural and mechanical behaviour of
components produced through fused deposition modelling.
Keywords: additive technology, fused deposition modelling (FDM), PLA,
mechanical properties, analytical model.
Introduction
Achieving optimal product quality and affordability, coupled with rapid
production timelines and competitive pricing while adhering to safety standards and
other benchmarks, is essential for maintaining competitiveness in the worldwide
manufacturing arena. A crucial aspect of product development is the engineering design
journey, beginning with requirement identification and culminating in a prototype primed
for manufacturing. The industrial perspective has shifted from conventional product
development approaches to additive technology, owing to the substantial capacity of
additive manufacturing techniques to curtail product development cycles and expenses.
Additive technologies, commonly known as 3D printing, have demonstrated
significant relevance and potential across various scientific disciplines. These
technologies involve creating three-dimensional objects by adding material layer by
layer, as opposed to traditional subtractive manufacturing methods that involve cutting
away material from a solid block.
Additive technologies are extensively used in scientific research for rapid prototyping
and iterative design. Scientists and researchers can quickly create physical models of
complex structures, devices, or experimental setups, allowing them to visualise and test
ideas more effectively. Also, additive technologies can fabricate intricate and complex
geometries that are challenging or impossible to produce using traditional manufacturing
methods. This is particularly valuable in fields such as aerospace, materials science, and
nanotechnology. It should also be noted that 3D printing enhances science education
by providing tangible, hands-on experiences. It enables students and the general public
to interact with physical models, enhancing understanding and engagement in various
scientific concepts. One of the main advantages Additive technologies are explored
for sustainable practices, such as recycling plastics to create 3D printing filament and
fabricating energy-efficient components. Overall, additive technologies have a broad
and transformative impact on scientific research, offering innovative solutions across
diverse disciplines and fostering new avenues for exploration and discovery.
There are seven categories of additive manufacturing (AM) processes [1]. These
categories are based on the type of energy source and the materials used. Thus, parts
can be printed using various additive manufacturing processes, including Material
Extrusion, Photopolymerization, Jetting, Lamination, and other techniques. Each of
these processes has its own unique characteristics, advantages, and limitations, making
them suitable for different applications and industries. These processes offer a wide
range of options for AM. As mentioned earlier each process has its own advantages,
such as speed, accuracy, material compatibility, and post-processing requirements. The
choice of which process to use depends on factors like the intended application, material
requirements, part complexity, and production volume.
As technology continues to evolve, new AM processes and variations are being
developed, expanding the possibilities for creating complex and functional parts through
additive manufacturing. It’s essential to stay up-to-date with the latest advancements
in the field to make informed decisions about which process to use for a particular
project [2].
Among AM processes Material Extrusion is an inexpensive, faster printing method
and widely used technique. It is often referred to as Fused Deposition Modelling (FDM)
or Fused Filament Fabrication (FFF). There are several reasons for its popularity,
namely, accessibility and affordability, material variety, ease of use, build volume and
scalability, diverse applications, post-processing options, open-source community.
FDM uses a variety of thermoplastic materials that are extruded through a heated
nozzle to build up layers and create 3D objects. The choice of material depends on the
specific application, functional requirements, and desired properties of the final part.
The mechanical properties of different Fused Deposition Modelling materials can vary
significantly. Each material has its own set of strengths, weaknesses, and characteristics
that make it suitable for specific applications.
This article uses Polylactic Acid (PLA) material as an example. PLA is a widespread
and environmentally friendly bioplastic derived from renewable resources like cornstarch
or sugarcane. It’s easy to print, has low warping, and is suitable for a wide range of
applications. The print material plays a key role in the mechanical properties of the
manufactured part. This article proposes to conduct a study in order to determine the
mechanical properties of parts manufactured by FDM and compare the results with a
computer model. Currently, numerous studies have been made by different researchers
[3-7]. Kumar and Singh [3] use multi-objective optimization to examine mechanical
characteristics of PLA. The accepted mechanical properties of PLA were unified by
optimising the FDM process parameters using Taguchi method. Croccolo et al. [8]
compares obtained experimental data with an analytical model which was developed
to predict the strength and the stiffness characteristics of FDM parts. Obtained model
was compared with experimental and affirmed.
Current study investigates simulation models of specimens that previously were
tested under different axial loads. Considering the works observed earlier, the relevance
of the work is proved by the theoretical and practical significance of the topic.
Materials and Methods
This article mainly explores the mechanical properties of parts that are made using
3D printing. The experimental process includes samples made of polylactic acid, as
was mentioned earlier a widely used material for FDM parts. The selected filament
belongs to Filamentive and has a diameter of 2.85 mm in white colour. All samples
were printed on an Ultimaker S5 printer with one nozzle. The nozzle was 0.8 mm in
diameter. A Cura program was used to obtain the G-code. It is also known that print
settings have an impact on part quality [9–11]. For this reason, all print parameters
were constant for all samples. At the same time, past experience and recommendations
from equipment producers were taken into account in order to set parameters. Sample
density was set at 100 %.
The schematic diagram and dimensions of the samples were indicated in Figure 1.
ISO-527-2-2012 standard was taken into consideration to prototype the 3D model of
the tensile test specimens in the CAD software. The experiments were conducted on a
Hounsfield-H10Ks universal testing machine with a capacity of 10 kN. The uniaxial
test is one of the most commonly performed tests in the field of mechanical testing
of materials. This test is designed to assess the mechanical properties of a material
under different forces. It provides valuable information about how a material responds
to applied loads, allowing it to determine various mechanical characteristics. This
information is crucial for material selection, design, and ensuring the safety and reliability
of various engineering applications.
Figure 1 – Tensile specimen dimensions (mm)
In addition to the experimental model for strength assessment, a computer model
was also built by means of the ANSYS program. Computer simulations can be utilised to
predict and analyse the behaviour of material and structures under different conditions.
This software program is based on the finite element method (FEM). The finite element
method is a numerical technique used to solve complex engineering and mathematical
problems by breaking down a continuous system into smaller, more manageable
elements. However, it’s important to note that the accuracy of the simulation heavily
relies on the accuracy of the input data and assumptions made during the modelling
process.
Calculation scheme of the sample outlined on Figure 2. One end of the part is rigidly
fixed, the second end is subjected to a vertical tensile force of 2466 N.
Figure 2 – Specimen boundary conditions for tension
Young’s modulus was adopted on the basis of engineering tests of 5 samples
and corresponds to the arithmetic mean. Other values of the boundary conditions are
presented in Table 1.
Table 1 – Linear parameters of PLA specimens
Result and Discussion
The aim of this research is to assess the mechanical characteristics of components
produced using the FDM technique through a combination of experimental and
computational approaches. Tensile, flexural and compression loads were applied to
the specimens in figure 1.
Figure 3 represents the tensile and flexural test results for the set of specimens
investigated in this study. As indicated in this diagram, the specimens exhibit tensile
strengths of 61, 62.5, 61.9, 61.9, and 61.5 MPa (with a standard deviation of 0.5 MPa).
In this manner, it can be asserted that the trials are reliable.
Figure 3 – Stress-strain curves for PLA samples
Additionally, the empirical results align with the values presented in previous studies
conducted by other researchers [12, 13].
The numerical technique yielded a normal stress of 62.43 MPa along the Y-axis at
the midpoint of the estimated sample length (Figure 4). Thus, the value of the numerical
method slightly exceeds the arithmetic mean value of the stress obtained on the basis
of the experiment on 0.67 MPa.
Figure 4 – Y-axis normal stress and its value
at the midpoint of the estimated sample length
This problem was solved in a linear formulation, where Hooke’s law is satisfied, and
this is obvious from Figure 5. For evaluation purposes, we can determine the Young’s
Modulus utilising the following equation:
As a result, the same average value is obtained, which was obtained empirically.
Figure 5 – Graph of stress versus relative longitudinal strain
at the midpoint of a PLA sample
Conclusions
The primary outcome of the research paper revolves around the potential to forecast
the mechanical characteristics of Fused Deposition modelled components through the
utilisation of empirical data. Using experimentally derived mechanical attributes, a linear
formulation was employed to conduct a numerical computation. The variance between
the two techniques was negligible, constituting a mere 1 % disparity.
The suggested analytical model holds the potential to serve as a valuable instrument
for FDM designers and manufacturers. Specifically, it can offer guidance in assessing
attainable strength or stiffness by adjusting parameters related to the components.
Hence, it is feasible to employ analytical models for foreseeing the structural
performance of FDM components or similar types of AM components, relying on
material characteristics. As a result, these analytical models can support the 3D
printing procedure, thereby mitigating the necessity for time-intensive and expensive
conventional experimental methods.
REFERENCES
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Modeling for Mechanical Properties of Biopolymer Parts Using the Grey-Taguchi
Method//Chinese Journal of Mechanical Engineering. 2023. – 36:30
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12 Laureto, J. J., Pearce, J. M. Anisotropic mechanical property variance between
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Material received on 30.08.23.
*A. Ракишев1, Б. Доненбаев2, Х. Р. Джамалудин3
1,2Әбілқас Сағынов атындағы Қарағанды техникалық университеті,
Қазақстан Республикасы, Қарағанды қ.;
3Малайзия технология университеті, Малайзия, Куала-Лумпур.
Материал 30.08.23 баспаға түсті.
FDM (3D БАСЫЛҒАН) БӨЛШЕКТЕРІНІҢ МЕХАНИКАЛЫҚ
СИПАТТАМАЛАРЫН ЗЕРТТЕУ: ЭМПИРИКАЛЫҚ
ЖӘНЕ КОМПЬЮТЕРЛІК ӘДІСТЕР
Балқытып тұндырумен үлгілеу, сонымен қатар жіпті балқытумен
жасау әдісі, аддитивті өндіріс әдісі болып табылады. Әртүрлі пайдалану
мүмкіндіктеріне байланысты өндірістің әр саласында үлкен қызығушылыққа
ие. Бұл жұмыста ISO-527-2-2012 стандартына сәйкес 3 D басып шығарылған
полилактикалық қышқыл (PLA) үлгілерінің созылу күші мен серпімділік
модулі зерттеледі. Жасалған бөлшектердің механикалық сипаттамалары
тәжірибелік жағынан да, есептелген жағынан да қарастырылады.
Компьютердің жүктемесі мен беріктігін есептеу үшін ANSYS бағдарламасында
соңғы элементтер әдісі қолданылды.
Тәжірибе үлгілері балқытып тұндыру тәсілі арқылы дайындалды.
Тәжірибе нәтижелері механикалық сипаттамаларды бағалау үшін қажетті
барлық негізгі инженерлік константаларды алу үшін пайдаланылды.
Теориялық модельдің дұрыстығы шамамен 1 % орташа қателерді көрсететін
эксперименттік деректердің мәнімен жан-жақты салыстыру арқылы
расталды.
Бұл зерттеудің мақсаты балқытып тұндырумен үлгілеу арқылы алынған
компоненттердің механикалық қасиетерін болжаудағы аналитикалық үлгінің
тиімділігін бағалау болып табылады.
Кілтті сөздер: аддитивті технологиялар, балқытып тұндыру әдісі
(FDM), PLA, механикалық қасиеттер, аналитикалық үлгі.
*A. Ракишев1, Б. Доненбаев1, Х. Р. Джамалудин2
1,2Карагандинский технический университет имени
Абылкаса Сагинова, Республика Казахстан, г. Караганда;
3Университеты технологий Малайзии, Малайзия, Куала-Лумпур.
Материал поступил в редакцию 30.08.23.
ИССЛЕДОВАНИЕ МЕХАНИЧЕСКИХ ХАРАКТЕРИСТИК FDM
ДЕТАЛЕЙ (3D ПЕЧАТИ): ЭМПИРИЧЕСКИЕ
И КОМПЬЮТЕРНЫЕ МЕТОДЫ
Моделирование с наплавлением, также называемое изготовлением
наплавленных нитей, представляет собой метод аддитивного производства,
который привлек значительное внимание в различных отраслях
промышленности из-за его разнообразных применений. В этой работе
исследуются предельная прочность на разрыв и модуль упругости образцов
полимолочной кислоты (PLA), напечатанных на 3D-принтере, в соответствии
со стандартом ISO-527-2-2012. Механические характеристики созданных
деталей рассматриваются как с экспериментальной, так и с расчетной
стороны. Метод конечных элементов в среде ANSYS использовался для
компьютерных расчетов нагрузки и прочности.
Образцы для растяжения изготавливаются с использованием подхода
моделирования наплавления. Экспериментальные результаты были
использованы для получения всех основных инженерных констант, необходимых
для оценки механического поведения. Обоснованность теоретической модели
была подтверждена путем всестороннего сравнения со значительным
объемом экспериментальных данных, демонстрирующих средние ошибки
примерно 1 %.
Целью данного исследования является оценка эффективности и
действенности аналитических моделей при прогнозировании структурного и
механического поведения компонентов, полученных с помощью моделирования
методом послойного наплавления.
Ключевые слова: аддитивные технологии, метод послойного наплавления
(FDM), PLA, механические свойства, аналитическая модель.
