scholarly journals Design and Characterization of Sheet-Based Gyroid Porous Structures with Bioinspired Functional Gradients

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3844
Author(s):  
Yuan Jin ◽  
Haoyu Kong ◽  
Xueyong Zhou ◽  
Guangyong Li ◽  
Jianke Du
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Biomechanical Properties ◽  
Potential Method ◽  
Structural Features ◽  
Design Parameters ◽  
Porous Scaffolds ◽  
Porous Structures ◽  
Compression Tests ◽  
Graded Structures

A new type of sheet porous structures with functionally gradients based on triply periodic minimal surfaces (TPMS) is proposed for designing bone scaffolds. The graded structures were generated by constructing branched features with different number of sheets. The design of the structure was formulated mathematically and five types of porous structure with different structural features were used for investigation. The relative density (RD) and surface area to volume (SA/V) ratio of the samples were analyzed using a slice-based approach to confirm their relationships with design parameters. All samples were additively manufactured using selective laser melting (SLM), and their physical morphologies were observed and compared with the designed models. Compression tests were adopted to study the mechanical properties of the proposed structure from the obtained stress–strain curves. The results reveal that the proposed branched-sheet structures could enhance and diversify the physical and mechanical properties, indicating that it is a potential method to tune the biomechanical properties of porous scaffolds for bone tissue engineering (TE).

Experimental investigation of the mechanical behavior of glass fiber/high fluidity polyamide-based composites for automotive market

2021 ◽  
pp. 073168442110140
Author(s):  
Hossein Ramezani-Dana ◽  
Moussa Gomina ◽  
Joël Bréard ◽  
Gilles Orange
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Mechanical Performance ◽  
Physical And Mechanical Properties ◽  
Ultimate Strain ◽  
Uniaxial Tensile ◽  
Compression Tests ◽  
Automotive Market ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Reinforcement

In this work, we examine the relationships between the microstructure and the mechanical properties of glass fiber–reinforced polyamide 6,6 composite materials ( V f = 54%). These materials made by thermocompression incorporate different grades of high fluidity polyamide-based polymers and two types of quasi-UD glass fiber reinforcement. One is a classic commercial fabric, while the other specially designed and manufactured incorporates weaker tex glass yarns (the spacer) to increase the planar permeability of the preform. The effects of the viscosity of the polymers and their composition on the wettability of the reinforcements were analyzed by scanning electron microscopy observations of the microstructure. The respective influences of the polymers and the spacer on the mechanical performance were determined by uniaxial tensile and compression tests in the directions parallel and transverse to the warp yarns. Not only does the spacer enhance permeability but it also improves physical and mechanical properties: tensile longitudinal Young’s modulus increased from 38.2 GPa to 42.9 GPa (13% growth), tensile strength increased from 618.9 MPa to 697 MPa (3% growth), and decrease in ultimate strain from 1.8% to 1.7% (5% reduction). The correlation of these results with the damage observed post mortem confirms those acquired from analyses of the microstructure of composites and the rheological behaviors of polymers.

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

Characteristics and Biocompatibility of the Hydroxyapatite Based Two Ternary Biocomposites

2016 ◽  
Vol 720 ◽  
pp. 130-140
Author(s):  
Berrak Bulut ◽  
Ziya Engin Erkmen ◽  
Eyup Sabri Kayali
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Secondary Phase ◽  
In Vitro Test ◽  
Compression Tests ◽  
Vitro Test ◽  
Dental Applications ◽  
The Ideal

Hydroxyapatite (HA) is a very popular bioceramic for orthopedic and dental applications. Although HA has excellent biocompatibility, its inferior mechanical properties make it unsuitable for load-bearing implant applications. Therefore, HA should be strengthened by a secondary phase for robust mechanical properties. The aim of this study was to compare the properties of HA-Al2O3 (HAC) and HA-ZrO2 (HZC) composites with the addition of 5 and 10 wt% commercial inert glass (CIG); independently. The mixture powders were pressed and then, the pellets were sintered between 1000-1300 °C for 4 hours. Microstructural characterizations were carried out using SEM + EDS and XRD, while hardness and compression tests were done to measure mechanical properties. In order to investigate the biocompatibility behavior of the samples in vitro and in vivo tests were performed. The mechanical properties of HAC composites increased with rising CIG content and increasing sintering temperature. For HZC composites, increasing CIG content caused an elevation in hardness and a decrease in compressive strength values at 1300 °C. The composites having the best physical and mechanical properties also showed improved bioactive properties at in vitro test. In this study, the ideal composite was selected as HZC5 sintered at 1200 °C depending on the microstructure, mechanical and biocompatibility properties.

scholarly journals GEOMETRY AND MECHANICAL PROPERTIES OF A 3D-PRINTED TITANIUM MICROSTRUCTURE

2018 ◽  
Vol 15 ◽  
pp. 104-108
Author(s):  
Luboš Řehounek ◽  
Petra Hájková ◽  
Petr Vakrčka ◽  
Aleš Jíra
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Uniaxial Compression ◽  
Elastic Moduli ◽  
Weight Ratio ◽  
Porous Structures ◽  
Compression Tests ◽  
Local Material ◽  
3D Printed ◽  
Titanium Microstructure

Construction applications sometimes require use of a material other than construction steel or concrete – mainly in cases, where strength to weight ratio needs to be considered. A suitable solution to this problem are structures manufactured using the 3D printing process, as they have a very good strength to weight ratio (i.e.: Ti-6Al-4V – σ<sub>ult</sub> = 900 MPa and ρ = 4500 kg/m<sup>3</sup>). Trabecular structures are porous structures with local material characteristics identical to their commonly manufactured counterparts, but due to their geometry, they have different global mechanical properties and are suited for special applications. We designed and manufactured six variants of these structures and subjected them to uniaxial compression tests, nanoindentation tests and subsequently evaluated their differences and elastic moduli. The values of global moduli E are in the range of 2.55 GPa – 3.55 GPa for all specimens.

scholarly journals Fused Deposition Modeling of Poly (lactic acid)/Macadamia Composites—Thermal, Mechanical Properties and Scaffolds

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 258 ◽  
Author(s):  
Xiaohui Song ◽  
Wei He ◽  
Huadong Qin ◽  
Shoufeng Yang ◽  
Shifeng Wen
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Fused Deposition Modeling ◽  
Poly Lactic Acid ◽  
Porous Scaffolds ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Structural Parts

In this work Macadamia nutshell (MS) was used as filler in fused deposition modeling (FDM) of Poly (lactic acid) (PLA) composites filaments. Composites containing MS both treated and untreated with alkali and silane were investigated by means of Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), Thermogravimetry (TG), scanning electron microscopy (SEM). The results showed that the treated MS composites had better thermal stability. Furthermore, compression tests were carried out. The PLA with 10 wt% treated MS composite was found possessing the best mechanical properties which was almost equivalent to that of the pure PLA. Finally, porous scaffolds of PLA/10 wt% treated MS were fabricated. The scaffolds exhibited various porosities in range of 30–65%, interconnected holes in size of 0.3–0.5 mm, micro pores with dimension of 0.1–1 μm and 37.92–244.46 MPa of elastic modulus. Those values indicated that the FDM of PLA/MS composites have the potential to be used as weight lighter and structural parts.

scholarly journals Expansion volume of alkali activated foamed cork composites from tungsten mining mud waste with aluminium

2019 ◽  
Vol 274 ◽  
pp. 03002
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes ◽  
Haroon Ihsan ◽  
John Pickstone ◽  
Nuno Estrada
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Porous Structures ◽  
Expansion Process ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

Several mixes of alkali activated foams from tungsten mud waste (MW), grounded glass (GG) and metakaolin (MK) were developed incorporating expanded granulated cork (EGC). This study presents preliminary results of the expansion process obtained with the addition of aluminium (AL) powder as a foaming agent. 0.3 wt.%, 0.4 wt.% to 0.5wt.% of AL powder were added to the alkali activated matrix. The physical and mechanical properties of the obtained foams, the effects of the type and amount of the foaming agent added are presented and discussed. Highly porous structures were obtained, with overall expansion up to 68.2% when the AL powder was added. The size and distribution of pores are shown. The compressive strength of foams in the case of highly porous structures achieved of 1.2 MPa for the samples containing 0.5 wt.% of AL powder. Mechanical and thermal properties of the cured structure are good and can therefore be used for applications in acoustic panels and lightweight prefabricated components for thermal insulation purposes.

Study of rheological behaviours of electrostatic thermoset powder coatings

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Morteza Ehsani ◽  
Ali Akbar Yousefi ◽  
Saeed Samiei Yeganeh
Keyword(s):  
Mechanical Properties ◽  
Dynamic Viscosity ◽  
Physical And Mechanical Properties ◽  
Powder Coating ◽  
Curing Temperature ◽  
Design Parameters ◽  
Powder Coatings ◽  
Gel Time ◽  
Rheological Measurements ◽  
The Impact

AbstractThe use of dynamic viscosity/time (temperature) cure curves is seen as a powerful technique to quantify formulation and resin design parameters. The behaviour of different thermoset powder coating systems, epoxy/polyester (50/50, 40/60 and 30/70) as well as the impact of the filler, the curing temperature and the frequency upon gel-time have been examined based upon the rheological measurements and compared with PE/TGIC systems. Two disparate methodologies have been utilized to determine gel-time. The behaviour of dissimilar systems bearing different formulations has been compared by means of the non-isothermal DSC test. The effects of resin percentage and the formulation on physical and mechanical properties of coating have been studied.

scholarly journals Polycaprolactone Foam Functionalized With Chitosan Microparticles – a Suitable Scaffold for Cartilage Regeneration

2016 ◽  
pp. 121-131 ◽  
Author(s):  
E. FILOVÁ ◽  
B. JAKUBCOVÁ ◽  
I. DANILOVÁ ◽  
E. KUŽELOVÁ KOŠŤÁKOVÁ ◽  
T. JAROŠÍKOVÁ ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Growth ◽  
Dna Content ◽  
Viscoelastic Properties ◽  
Cartilage Regeneration ◽  
Biomechanical Properties ◽  
Porous Scaffolds ◽  
Chitosan Microparticles ◽  
Salt Leaching ◽  
Cell Growth And Differentiation

For biodegradable porous scaffolds to have a potential application in cartilage regeneration, they should enable cell growth and differentiation and should have adequate mechanical properties. In this study, our aim was to prepare biocompatible scaffolds with improved biomechanical properties. To this end, we have developed foam scaffolds from poly-Ɛ-caprolactone (PCL) with incorporated chitosan microparticles. The scaffolds were prepared by a salt leaching technique from either 10 or 15 wt% PCL solutions containing 0, 10 and 20 wt% chitosan microparticles, where the same amount and size of NaCl was used as a porogen in all the cases. PCL scaffolds without and with low amounts of chitosan (0 and 10 wt% chitosan) showed higher DNA content than scaffolds with high amounts of chitosan during a 22-day experiment. 10 wt% PCL with 10 and 20 wt% chitosan showed significantly increased viscoelastic properties compared to 15 wt% PCL scaffolds with 0 and 10 wt% chitosan. Thus, 10 wt% PCL scaffolds with 0 wt% and 10 wt% chitosan are potential scaffolds for cartilage regeneration.

scholarly journals Analysis of efficiency of drilling equipment use in mining operations

2021 ◽  
Vol 315 ◽  
pp. 02018
Author(s):  
Yuriy Masaev ◽  
Vladislav Masaev ◽  
Yuriy Drozdenko
Keyword(s):  
Mechanical Properties ◽  
Energy Intensity ◽  
Physical And Mechanical Properties ◽  
Structural Features ◽  
Ore Deposits ◽  
Mining Operations ◽  
Drilling Equipment ◽  
Wide Range ◽  
Mine Workings ◽  
Underground Method

When developing coal and ore deposits by underground method, it is necessary to carry out a large volume of preparatory mine workings using drilling and blasting operations. Minerals are found in rocks under various conditions and their physical and mechanical properties change in a wide range. Under such conditions, it is necessary to use drilling machines this different to the principle of action and structural features. The article considers geometric parameters of roc cutters, peculiarities of drilling modes, affecting energy intensity and drilling productivity in rocks with different strength coefficient.

scholarly journals Analysis of Mechanical Properties and Permeability of Trabecular-Like Porous Scaffold by Additive Manufacturing

2021 ◽  
Vol 9 ◽  
Author(s):  
Long Chao ◽  
Chen Jiao ◽  
Huixin Liang ◽  
Deqiao Xie ◽  
Lida Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Repair ◽  
Bone Cells ◽  
Porous Scaffold ◽  
Bone Ingrowth ◽  
Voronoi Tessellation ◽  
Stress Shielding ◽  
Porous Scaffolds ◽  
Porous Structures ◽  
Element Analysis

Human bone cells live in a complex environment, and the biomimetic design of porous structures attached to implants is in high demand. Porous structures based on Voronoi tessellation with biomimetic potential are gradually used in bone repair scaffolds. In this study, the mechanical properties and permeability of trabecular-like porous scaffolds with different porosity levels and average apertures were analyzed. The mechanical properties of bone-implant scaffolds were evaluated using finite element analysis and a mechanical compression experiment, and the permeability was studied by computational fluid dynamics. Finally, the attachment of cells was observed by confocal fluorescence microscope. The results show that the performance of porous structures can be controlled by the initial design of the microstructure and tissue morphology. A good structural design can accurately match the performance of the natural bone. The study of mechanical properties and permeability of the porous structure can help address several problems, including stress shielding and bone ingrowth in existing biomimetic bone structures, and will also promotes cell adhesion, migration, and eventual new bone attachment.

Sign in / Sign up

Export Citation Format

Share Document