scholarly journals Effects of deposition - strategy - induced raster gaps and infill voids on the compressive strength of 3D printed isogrid structures

2021 ◽  
Author(s):  
Alan Mauricio Guajardo-Trevino ◽  
Horacio Ahuett-Garza ◽  
Pedro Orta-Castanon ◽  
Pedro Daniel Urbina-Coronado ◽  
Christopher Saldana ◽  
...  
Keyword(s):  
Compressive Strength ◽  
3D Printed

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

2021 ◽  
Vol 15 (2) ◽  
pp. 8169-8177
Author(s):  
Berkay Ergene ◽  
İsmet ŞEKEROĞLU ◽  
Çağın Bolat ◽  
Bekir Yalçın
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
Wall Thickness ◽  
Lattice Structure ◽  
Honeycomb Structure ◽  
Cellular Structures ◽  
Compression Tests ◽  
Absorbed Energy ◽  
Great Opportunity ◽  
3D Printed

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.

scholarly journals In Vivo Reconstruction of the Acetabular Bone Defect by the Individualized Three-Dimensional Printed Porous Augment in a Swine Model

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jun Fu ◽  
Yi Xiang ◽  
Ming Ni ◽  
Xiaojuan Qu ◽  
Yonggang Zhou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Bone Defect ◽  
Bone Ingrowth ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Acetabular Bone ◽  
Acetabular Bone Defect ◽  
3D Printed ◽  
Matching Degree

Background and Purpose. This study established an animal model of the acetabular bone defect in swine and evaluated the bone ingrowth, biomechanics, and matching degree of the individualized three-dimensional (3D) printed porous augment. Methods. As an acetabular bone defect model created in Bama miniswine, an augment individually fabricated by 3D print technique with Ti6Al4V powders was implanted to repair the defect. Nine swine were divided into three groups, including the immediate biomechanics group, 12-week biomechanics group, and 12-week histological group. The inner structural parameters of the 3D printed porous augment were measured by scanning electron microscopy (SEM), including porosity, pore size, and trabecular diameter. The matching degree between the postoperative augment and the designed augment was assessed by CT scanning and 3D reconstruction. In addition, biomechanical properties, such as stiffness, compressive strength, and the elastic modulus of the 3D printed porous augment, were measured by means of a mechanical testing machine. Moreover, bone ingrowth and implant osseointegration were histomorphometrically assessed. Results. In terms of the inner structural parameters of the 3D printed porous augment, the porosity was 55.48 ± 0.61 % , pore size 319.23 ± 25.05   μ m , and trabecular diameter 240.10 ± 23.50   μ m . Biomechanically, the stiffness was 21464.60 ± 1091.69   N / mm , compressive strength 231.10 ± 11.77   MPa , and elastic modulus 5.35 ± 0.23   GPa , respectively. Furthermore, the matching extent between the postoperative augment and the designed one was up to 91.40 ± 2.83 % . Besides, the maximal shear strength of the 3D printed augment was 929.46 ± 295.99   N immediately after implantation, whereas the strength was 1521.93 ± 98.38   N 12 weeks after surgery ( p = 0.0302 ). The bone mineral apposition rate (μm per day) 12 weeks post operation was 3.77 ± 0.93   μ m / d . The percentage bone volume of new bone was 22.30 ± 4.51 % 12 weeks after surgery. Conclusion. The 3D printed porous Ti6Al4V augment designed in this study was well biocompatible with bone tissue, possessed proper biomechanical features, and was anatomically well matched with the defect bone. Therefore, the 3D printed porous Ti6Al4V augment possesses great potential as an alternative for individualized treatment of severe acetabular bone defects.

Enhancement of the Compressive Strength of 3D-Printed Polylactic Acid(PLA) by Controlling Internal Pattern

2021 ◽  
Vol 1023 ◽  
pp. 75-81
Author(s):  
Aappo Mustakangas ◽  
Atef Hamada ◽  
Antti Järvenpää
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Polylactic Acid ◽  
Optical Microscope ◽  
Fused Filament Fabrication ◽  
Loading Direction ◽  
Compressive Flow ◽  
3D Printed ◽  
Cost Efficient ◽  
Loading Axis

Cost-efficient 3D-printing can create a lot of new opportunities in engineering as it enables rapid prototyping of models and functional parts. In the present study, Polylactic acid (PLA) cubic specimens with different types of infill patterns (IPs), rectilinear, grid and cuboid, were additively manufactured by Fused Filament Fabrication 3D-printing. The PLA cubes are fabricated with one perimeter and different IPs density (10, 20, and 30%). Subsequently, the compressive strengths of the PLA materials were measured in two loading directions, i.e., the layers building direction is parallel (PD) to the loading axis and perpendicular (ND) to the loading direction. An optical microscope was used to examine the deformed IPs in both loading directions. The compressive flow stress curves of the PLA cubes infilled with rectilinear and grid patterns exhibited strong fluctuations with lower compressive strengths in the loading direction along ND. The PLA with 30% grid IP revealed a superior strength of ~12 kN in the loading direction along PD. On the contrary, the same material exhibited a worst compressive strength 3 kN along ND.

scholarly journals Comparison of Dental Stone Models and Their 3D Printed Acrylic Replicas for the Accuracy and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4066
Author(s):  
Marta Czajkowska ◽  
Ewa Walejewska ◽  
Łukasz Zadrożny ◽  
Monika Wieczorek ◽  
Wojciech Święszkowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Impact Strength ◽  
Physical Properties ◽  
Diagnostic Tool ◽  
Medical Records ◽  
Diagnostic Value ◽  
Dental Models ◽  
3D Printed ◽  
The Impact

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces. The mechanical properties of acrylic and stone samples, specifically the impact strength, shore D hardness, and flexural and compressive strength were investigated according to ISO standards. The matching of models’ surfaces was the highest on the level of peaks of cusps (average lack of deviations, 0.21 mm) and the lowest on the level of all teeth surfaces (average lack of deviations, 0.64 mm). Acrylic samples subjected to mechanical testing, as expected, showed higher mechanical properties as compared to the specimens made of dental stone. In the present study we demonstrated that 3D printed acrylic models could be ideal representatives in the case of use as a diagnostic tool and as a part of medical records. The acrylic samples exhibited not only higher mechanical properties, but also showed better accuracy comparing to dental stone.

scholarly journals Predicting Compressive Strength of 3D Printed Mortar in Structural Members Using Machine Learning

2021 ◽  
Vol 11 (22) ◽  
pp. 10826
Author(s):  
Hamed Izadgoshasb ◽  
Amirreza Kandiri ◽  
Pshtiwan Shakor ◽  
Vittoria Laghi ◽  
Giada Gasparini
Keyword(s):  
Machine Learning ◽  
Compressive Strength ◽  
Cement Mortar ◽  
Iteration Process ◽  
Machine Learning Method ◽  
Structural Members ◽  
Grasshopper Optimization Algorithm ◽  
3D Printed ◽  
Grasshopper Optimization ◽  
Artificial Neural Network Ann

Machine learning is the discipline of learning commands in the computer machine to predict and expect the results of real application and is currently the most promising simulation in artificial intelligence. This paper aims at using different algorithms to calculate and predict the compressive strength of extrusion 3DP concrete (cement mortar). The investigation is carried out using multi-objective grasshopper optimization algorithm (MOGOA) and artificial neural network (ANN). Given that the accuracy of a machine learning method depends on the number of data records, and for concrete 3D printing, this number is limited to few years of study, this work develops a new method by combining both methodologies into an ANNMOGOA approach to predict the compressive strength of 3D-printed concrete. Some promising results in the iteration process are achieved.

scholarly journals Biocompatible Customized 3D Bone Scaffolds Treated with CRFP, an Osteogenic Peptide

2021 ◽  
Vol 8 (12) ◽  
pp. 199
Author(s):  
Vamiq M. Mustahsan ◽  
Amith Anugu ◽  
David E. Komatsu ◽  
Imin Kao ◽  
Srinivas Pentyala
Keyword(s):  
Compressive Strength ◽  
Bone Growth ◽  
Bone Matrix ◽  
Stress Shielding ◽  
Acrylonitrile Butadiene Styrene ◽  
3D Printed ◽  
Bone Graft Substitutes ◽  
Matrix Production ◽  
Receptor Fragment ◽  
Butadiene Styrene

Background: Currently used synthetic bone graft substitutes (BGS) are either too weak to bear the principal load or if metallic, they can support loading, but can lead to stress shielding and are unable to integrate fully. In this study, we developed biocompatible, 3D printed scaffolds derived from µCT images of the bone that can overcome these issues and support the growth of osteoblasts. Methods: Cylindrical scaffolds were fabricated with acrylonitrile butadiene styrene (ABS) and Stratasys® MED 610 (MED610) materials. The 3D-printed scaffolds were seeded with Mus musculus calvaria cells (MC3T3). After the cells attained confluence, osteogenesis was induced with and without the addition of calcitonin receptor fragment peptide (CRFP) and the bone matrix production was analyzed. Mechanical compression testing was carried out to measure compressive strength, stiffness, and elastic modulus. Results: For the ABS scaffolds, there was a 9.8% increase in compressive strength (p < 0.05) in the scaffolds with no pre-coating and the treatment with CRFP, compared to non-treated scaffolds. Similarly, MED610 scaffolds treated with CRFP showed an 11.9% (polylysine pre-coating) and a 20% (no pre-coating) increase (p < 0.01) in compressive strength compared to non-treated scaffolds. Conclusions: MED610 scaffolds are excellent BGS as they support osteoblast growth and show enhanced bone growth with enhanced compressive strength when augmented with CRFP.

scholarly journals Blood, Sweat and Tears: Extraterrestrial Regolith Biocomposites with in Vivo Binders

2021 ◽  
Author(s):  
Aled Roberts ◽  
Dominic Whittall ◽  
Rainer Breitling ◽  
Eriko Takano ◽  
Jonny J. Blaker ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Serum Albumin ◽  
Spider Silk ◽  
Protein Secondary Structure ◽  
3D Printed ◽  
Martian Regolith ◽  
Β Sheet ◽  
Opening Up ◽  
Average Compressive Strength

In this work, we explore the use of human serum albumin (HSA) – a common protein obtained from blood plasma – as a binder for simulated Lunar and Martian regolith to produce so-called extraterrestrial regolith biocomposites (ERBs). In essence, HSA produced by astronauts in vivo could be extracted on a semi-continuous basis and combined with Lunar or Martian regolith to produce a concrete-like material. Employing a simple fabrication strategy, HSA-based ERBs were produced and displayed compressive strengths as high as 25.0 MPa. For comparison, standard concrete typically has a compressive strength ranging between 20 and 32 MPa. The incorporation of urea – which could be extracted from the urine, sweat or tears of astronauts – could further increase the compressive strength by over 300% in some instances, with the best-performing formulation having an average compressive strength of 39.7 MPa. Furthermore, we demonstrate that HSA-ERBs can be 3D-printed, opening up an interesting potential avenue for extraterrestrial construction using human-derived feedstocks. The mechanism of adhesion was investigated and attributed to the dehydration-induced reorganisation of the protein secondary structure into a densely hydrogen-bonded, supramolecular β-sheet network – analogous to the cohesion mechanism of spider silk. For comparison, synthetic spider silk and bovine serum albumin (BSA) were also investigated as regolith binders – which could also feasibly be produced on a Martian colony with future advancements in biomanufacturing technology.<br>

scholarly journals Influence of curing age on high-temperature properties of additive manufactured geopolymer mortar

2020 ◽  
Vol 218 ◽  
pp. 03019
Author(s):  
Xiaohong Yin ◽  
Xiaodong Wang ◽  
Yuan Fang ◽  
Zhu Ding
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Flexural Strength ◽  
High Temperature Properties ◽  
Before And After ◽  
3D Printed ◽  
Curing Age

Some researches have been conducted on the application of geopolymer in 3D printing. However, there is no publication about the high-temperature properties of 3D printed geopolymer made from fly ash, slag, and metakaolin. This paper presents the experimental research on the mechanical properties of 3D printed geopolymer after being exposed to elevated empratures. The effects of curing age on high-temperature properties are analyzed. The heating temperasures were 300 °C, 600 °C, and 900 °C, and the holding time was one hour. After exposure to temperatures, the flexural strength of 3D printed geopolymer exhibited different change trends with increasing curing age for different exposure temperatures. Before and after exposure to elevated temperature, the 3D printed geopolymer experienced significant anisotropic compressive strengths. The change trends of compressive strength at different exposure temperatures wit hincreasing curing ages were different from each other on different loading directions.

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