scholarly journals MECHANICAL PROPERTIES OF 3D SCAFFOLDS FOR BONE REGENERATION / 3D KARKASŲ, SKIRTŲ KAULŲ REGENERACIJAI, MECHANINIŲ SAVYBIŲ TYRIMAS

2017 ◽  
Vol 8 (6) ◽  
pp. 587-591
Author(s):  
Deividas Mizeras ◽  
Andžela Šešok ◽  
Algirdas Vaclovas Valiulis ◽  
Justinas Gargasas ◽  
Irmantas Gedzevičius
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Bone Substitutes ◽  
Point Of View ◽  
Bone Tissue Regeneration ◽  
3D Scaffolds ◽  
Bending Tests ◽  
Ethical Point ◽  
Additional Surgery ◽  
3D Printed

One of the biggest challenges in modern tissue engineering is a creation 3D scaffolds for bone tissue regeneration. Until now, in order to restore bone defects are used various bone substitutes (autologous and allogeneic), however, their usage is limited because is required additional surgery, possible complications, also limited their use is associated with ethical point of view. In this work we aim to determine the mechanical properties of 3D printed PLA objects having various orientation woodpile microarchitectures. In this work we chose three different 3D microarchitectures: woodpile BCC (each layer consists of parallel logs which are rotated 90 deg every next layer), woodpile FCC (every layer is additionally shifted half of the period in respect to the previous parallel log layer) and a rotating woodpile 60 deg (each layer is rotated 60 deg in respect to the previous one). Compressive and bending tests were carried out with TIRAtest2300 universal testing machine. We found that 60 deg rotating woodpile geometry had the highest mechanical values which were approximately about 3 times higher than the BCC or FCC microstructures. Vienas didžiausių šiuolaikinės audinių inžinerijos iššūkių yra 3D karkasų, skirtų kaulinio audinio regeneracijai, sukūrimas. Iki šiol, norint atstatyti kaulo defektus, naudojami įvairūs kaulo pakaitalai (autogeniniai ir alogeniniai), kurių naudojimo galimybės jau nebeatitinka poreikių, nes reikalinga papildoma operacija, galimos komplikacijos, taip pat ribotas jų naudojimas, susijęs su etinėmis pažiūromis. Šiame darbe lyginamos 3D spausdintuvu suformuotų mikrodarinių, skirtų kaulinio audinio defektui atkurti, mechaninės savybės. Darbe pasirinktos trys skirtingos 3D karkasų mikrostruktūros: woodpile BCC (kiekvienas sluoksnis susideda iš lygiagrečių rąstų, kurie keičiami 90 laipsnių kampu prieš tai esančio sluoksnio atžvilgiu), woodpile FCC (kiekvienas sluoksnis papildomai keičiasi per pusę periodo sluoksnio, esančio prieš tai, atžvilgiu) ir woodpile 60 deg (besisukanti rąstų rietuvė, kiekvienas tokios gardelės sluoksnis yra pasuktas 60 laipsnių prieš tai esančios atžvilgiu). Gniuždymo ir lenkimo bandymai buvo atlikti TIRAtest 2300 universalia bandymų mašina. Buvo nustatyta, kad, taikant 60 laipsnių kampu besikeičiančią woodpile geometriją, galima pasiekti didžiausias mechanines vertes, kurios buvo maždaug tris kartus didesnės nei woodfile BCC arba woodfile FCCmikrostruktūros.

scholarly journals Comparison of different microstructure scaffolds for tissue regeneration

2016 ◽  
Author(s):  
Andžela Šešok ◽  
Deividas Mizeras ◽  
Algirdas Vaclovas Valiulis ◽  
Julius Griškevičius ◽  
Mangirdas Malinauskas
Keyword(s):  
Mechanical Properties ◽  
Tissue Regeneration ◽  
Low Cost ◽  
Testing Machine ◽  
Raw Material ◽  
Bending Tests ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
3D Printed

In this work we aim to determine the mechanical properties of 3D printed PLA objects having various orientation woodpile microarchitectures. In this work we chose three different 3D microarchitectures: woodpile BCC (each layer consists of parallel logs which are rotated 90 deg every next layer), woodpile FCC (every layer is additionally shifted half of the period in respect to the previous parallel log layer) and a rotating woodpile 60 deg (each layer is rotated 60 deg in respect to the previous one). Compressive and bending tests were carried out TIRAtest2300 universal testing machine. We found that 60 deg rotating woodpile geometry had the highest values which was approximately 3 times than the BCC or FCC log arrangements. Thus we prove that employing low-cost equipment and applying the same raw material one can create objects of desired rigidity.

Study on Automobile Body Performance of Honeycomb Sandwich Composite Material

2012 ◽  
Vol 567 ◽  
pp. 146-149 ◽  
Author(s):  
Xue Mei Fan ◽  
Jian Feng Wang ◽  
Cheng Jin Duan ◽  
Xiang Xin Xia ◽  
Zhao Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Testing Machine ◽  
Sandwich Composite ◽  
Element Analysis ◽  
Bending Tests ◽  
Three Point Bending ◽  
Honeycomb Sandwich ◽  
Core Thickness ◽  
Honeycomb Sandwich Structure

In order to analyze the mechanical properties of Carbon/epoxy facings-Aluminum honeycomb sandwich structure, we simulated panels of different layers and core thickness using ABAQUS finite element analysis program. And three-point bending tests and shear tests were made on the same panels using electronic universal testing machine. In addition, we also made the same three-point bending tests on steel tubes to get a comparison with honeycomb sandwich panels. It could be seen that, the simulated results were basically identified with experimental results. The results indicated that core thickness played an important role in the panels’ bulking modulus, and number of carbon fiber layers decided the shear strength. As a whole, honeycomb sandwich structure was suitable for use in the car body with good mechanical properties under premise of lighter.

Failure of an Advanced Five Layers RT800 Composite

2015 ◽  
Vol 760 ◽  
pp. 299-304
Author(s):  
Vasile Gheorghe ◽  
Florin Teodorescu-Draghicescu ◽  
Dora Raluca Ionescu
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Testing Machine ◽  
Experimental Tests ◽  
Specific Weight ◽  
Materials Testing ◽  
Bending Tests ◽  
Three Point Bending ◽  
Median Part ◽  
Glass Mat

This paper presents mechanical properties of five layers RT800 glass mat laminate impregnated with polyester resin and subjected to three-point bending tests until break. The RT800 glass mat used as reinforcement presents randomly disposed short glass fibers with 845 g/m2specific weight. From the cured plate, twenty specimens have been cut and placed on a three-point bending device and tested using a materials testing machine with servo hydraulic command. The specimens have been carried out at Compozite Ltd Brasov and the experimental tests have been accomplished at SC INAR SA Brasov and Transilvania University of Brasov. Outstanding mechanical properties of this kind of material have been found in which the specimens have suffered delamination mainly in their median part.

scholarly journals Mechanical Properties of Flexible TPU-Based 3D Printed Lattice Structures: Role of Lattice Cut Direction and Architecture

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2986
Author(s):  
Victor Beloshenko ◽  
Yan Beygelzimer ◽  
Vyacheslav Chishko ◽  
Bogdan Savchenko ◽  
Nadiya Sova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lattice Structure ◽  
Pore Space ◽  
Thermoplastic Polyurethane ◽  
Bending Tests ◽  
Three Point Bending ◽  
Lattice Materials ◽  
3D Printed ◽  
Anisotropy Of Mechanical Properties

This study addresses the mechanical behavior of lattice materials based on flexible thermoplastic polyurethane (TPU) with honeycomb and gyroid architecture fabricated by 3D printing. Tensile, compression, and three-point bending tests were chosen as mechanical testing methods. The honeycomb architecture was found to provide higher values of rigidity (by 30%), strength (by 25%), plasticity (by 18%), and energy absorption (by 42%) of the flexible TPU lattice compared to the gyroid architecture. The strain recovery is better in the case of gyroid architecture (residual strain of 46% vs. 31%). TPUs with honeycomb architecture are characterized by anisotropy of mechanical properties in tensile and three-point bending tests. The obtained results are explained by the peculiarities of the lattice structure at meso- and macroscopic level and by the role of the pore space.

Improvement of the Mechanical Properties of Calcium Phosphate Bone Substitutes by Polycaprolactone Infiltration

2007 ◽  
Vol 361-363 ◽  
pp. 403-406 ◽  
Author(s):  
Marion Quiquerez ◽  
Marianna Peroglio ◽  
Laurent Gremillard ◽  
Jérôme Chevalier ◽  
Laurent Chazeau ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Maximum Stress ◽  
Bone Substitutes ◽  
Bending Tests ◽  
Ceramic Scaffold ◽  
Low Viscosity ◽  
Bimodal Pore Size Distribution ◽  
Interesting Candidate ◽  
Work Of Fracture

In this study we show that mechanical properties of bioceramic scaffolds can be significantly improved by repeated infiltration with a low-viscosity polycaprolactone solution. Biphasic calcium phosphate (BCP: 70% hydroxyapatite, 30% β-tricalcium phosphate) scaffolds characterized by a bimodal pore size distribution and a global porosity of 70% have been chosen as starting materials. Polymer content in the ceramic scaffold was varied so that an inorganic/organic ratio close to that of bone may be achieved. Work of fracture at maximum stress was 36 J/m2 for the ceramic scaffold alone and reached 127 J/m2 for the 8-times infiltrated samples. These results are superior to the ones previously obtained with polycaprolactone infiltrated alumina due to higher micropore content. We show that during bending tests, polycaprolactone phase formed fibrils while the crack propagated. Crack bridging by polycaprolactone ensured the integrity of the composite once the ceramic scaffold was broken and directly involved in the composite toughening. Because of its composition, microstructure and mechanical behavior of this kind composite can be an interesting candidate for bone substitution.

Studies on Processing Rheological and Mechanical Properties of Poly(lactic acid)/Sesbania Gum/Nano-silica Composites

2017 ◽  
Vol 25 (5) ◽  
pp. 395-404
Author(s):  
Qing Zhang
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Rheological Properties ◽  
Testing Machine ◽  
Silica Content ◽  
Impact Testing ◽  
Poly Lactic Acid ◽  
Nano Silica ◽  
Bending Tests ◽  
Sesbania Gum

Processing rheological properties of poly(lactic acid) (PLA)/sesbania gum (SG)/nano-silica composites were investigated with a torque rheometer, and mechanical properties were researched by a universal testing machine and a cantilever-beam impact testing machine. Effects of SG content, nano-silica content, the types of plasticisers, the plasticiser content and the rotor speed of a torque rheometer on the properties of composites were discussed. The results indicated that polyethylene glycol (PEG)20000 exhibited the best plasticising effect on the composites, and at the same time, did not increase energy consumption of the systems compared with other four plasticisers. As for the aspect of processing rheological properties, the optimum formulation for PLA/SG/ nano-SiO2/PEG20000 composites was: 100 parts of PLA, 8 parts of SG, 2 parts of nano-SiO2, and 5–10 parts of PEG20000. Comparing with unmodified PLA, the comprehensive mechanical properties of the composites improved greatly, based on the results of the tensile, impact and bending tests.

Validation of an Analytical Model Describing Mechanical Properties of Porous BCP Ceramics

2007 ◽  
Vol 361-363 ◽  
pp. 15-18
Author(s):  
François Pecqueux ◽  
Nathalie Payraudeau ◽  
Franck Tancret ◽  
Jean Michel Bouler
Keyword(s):  
Mechanical Properties ◽  
Biphasic Calcium Phosphate ◽  
Bone Substitutes ◽  
Mechanical Tests ◽  
Cold Isostatic Pressing ◽  
Bending Tests ◽  
Three Point Bending ◽  
Conventional Sintering ◽  
Critical Flaw ◽  
Modelling Approach

Macroporous biphasic calcium phosphate bioceramics, for use as bone substitutes, have been fabricated by cold isostatic pressing and conventional sintering, using naphthalene particles as a porogen to produce macropores. The resulting ceramics, composite materials made of hydroxyapatite and β-tricalcium phosphate containing various macroporosities and microporosities, have been submitted to compression and three-point bending tests. The mechanical tests performed on the sintered ceramics tend to validate the modelling approach and its hypothesis, i.e. the material can be considered as a microporous matrix containing isolated macropores, and the critical flaw is a macropore.

scholarly journals Comparing Properties of Variable Pore-Sized 3D-Printed PLA Membrane with Conventional PLA Membrane for Guided Bone/Tissue Regeneration

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1718 ◽  
Author(s):  
Hao Yang Zhang ◽  
Heng Bo Jiang ◽  
Jeong-Hyun Ryu ◽  
Hyojin Kang ◽  
Kwang-Mahn Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Bone Tissue Regeneration ◽  
Control Group ◽  
Micro Computed Tomography ◽  
Barrier Membranes ◽  
Pore Sizes ◽  
Small Pore ◽  
Superior Mechanical Properties ◽  
3D Printed

The aim of this study was to fabricate bioresorbable polylactide (PLA) membranes by 3D printing and compare their properties to those of the membranes fabricated by the conventional method and compare the effect of different pore sizes on the properties of the 3D-printed membranes. PLA membranes with three different pore sizes (large pore-479 μm, small pore-273 μm, and no pore) were 3D printed, and membranes fabricated using the conventional solvent casting method were used as the control group. Scanning electron microscopy (SEM) and micro-computed tomography (µ-CT) were taken to observe the morphology and obtain the porosity of the four groups. A tensile test was performed to compare the tensile strength, elastic modulus, and elongation at break of the membranes. Preosteoblast cells were cultured on the membranes for 1, 3 and 7 days, followed by a WST assay and SEM, to examine the cell proliferation on different groups. As a result, the 3D-printed membranes showed superior mechanical properties to those of the solvent cast membranes, and the 3D-printed membranes exhibited different advantageous mechanical properties depending on the different pore sizes. The various fabrication methods and pore sizes did not have significantly different effects on cell growth. It is proven that 3D printing is a promising method for the fabrication of customized barrier membranes used in GBR/GTR.

scholarly journals 3D-Printed Composite Bone Bricks For Large Bone Tissue Applications

2020 ◽  
Vol 318 ◽  
pp. 01009
Author(s):  
Evangelos Daskalakis ◽  
Fengyuan Liu ◽  
Anil A. Acar ◽  
Edera-Elena Dinea ◽  
Glen Cooper ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Tissue ◽  
Ceramic Composite ◽  
Manufacturing System ◽  
Low Cost ◽  
Ceramic Materials ◽  
Bone Tissue Regeneration ◽  
Porous Structures ◽  
3D Printed ◽  
Large Bone

This study investigates the use of low cost, customizable, biodegradable, polymer-ceramic composite porous structures (bone bricks) for large bone tissue regeneration. Different ceramic materials (hydroxyapatite (HA), β-tri-calcium phosphate (TCP) and Bioglass (45S5) were mixed with poly-ε-caprolactone (PCL). Bone bricks with different material compositions were produced using an extrusion-based additive manufacturing system. Produced bone bricks were morphologically and mechanically assessed. Results allowed to establish a correlation between scaffolds architecture and material composition and scaffolds performance. Reinforced scaffolds showed improved mechanical properties. Best mechanical properties were obtained with PCL/TCP bone bricks and topologies based on 38 double zig zag filaments and 14 spirals.

scholarly journals Reliability and Mechanical Properties of Materials Recycled from Multilayer Flexible Packages

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3992 ◽  
Author(s):  
Natividad Antón ◽  
Álvaro González-Fernández ◽  
Alberto Villarino
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Point Of View ◽  
Good Reliability ◽  
Simultaneous Application ◽  
Bending Tests ◽  
Food Packages ◽  
Pressure Time ◽  
Before And After

Present work proposes a recycling form of multilayer food packages to avoid their incineration, landfill of wastes or re-using of their individual components. The manufacturing process of the material consists of binding several sheets by the non-simultaneous application of temperature and pressure, these being bound by the fusion of the polyethylene, without any other adhesives. The influence of elected variables (temperature, pressure, time and number of sheets) on the mechanical properties is determined. Bending tests in three points were carried out, with the purpose of obtaining flexural strength and flexural modulus. Finally, the reliability was determined through the method of Weibull using different failure estimators for the most appropriate materials (relative to flexural strength and porosity values). Light microscopy to obtain information about defectology before and after tests was used. The results obtained by this type of material are very similar to those presented by wood-based materials and present good reliability from the strength point of view.

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