3D Printing of a Double Network Hydrogel with a Compression Strength and Elastic Modulus Greater than those of Cartilage

2017 ◽  
Vol 3 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Feichen Yang ◽  
Vaibhav Tadepalli ◽  
Benjamin J. Wiley
Keyword(s):  
Elastic Modulus ◽  
3D Printing ◽  
Compression Strength ◽  
Double Network

scholarly journals Bikomponent ve Karışım HDPE/LDPE Filamentlerin Üretimi ve 3B Yazıcılarda Kullanımı

2021 ◽  
Vol 28 (121) ◽  
pp. 2-15
Author(s):  
Oğuzhan Uslu ◽  
Yakup Aykut
Keyword(s):  
3D Printing ◽  
Compression Strength ◽  
Honeycomb Structure ◽  
Strength Test ◽  
3D Printer ◽  
Thermal And Mechanical Properties ◽  
Thermoplastic Material ◽  
3D Objects ◽  
3D Methods ◽  
Test Result

Thermoplastic polymer have been used in 3D printing technologies since the objects produced via 3D methods by using thermoplastic materials can be recycled and reformed easly. In order to use a thermoplastic material in the 3D technologies, the thermplastic polymers are spun into fiber structures and then 3D objects are produced from these fibers. In this regard, low density polyethylene (LDPE) and high density polyethylene (HDPE) were melt spun into fiber with various construction including neat, blend and bicomponent forms. Chemical, microstructural, thermal and mechanical properties of the produced fibers were investigated. 3D printable properties of the prepared fibers were observed by using them in the 3D printer. It was observed that bicomponent LDPE/HDPE fibers were the most suitable fiber to produced 3D sample in the lab scale 3D printer. 3D honeycomb structure was produced from this fiber and its compression strength property was investigated by comparing the same size of the PLA honeycomb structure. Compression strength test result of the honeycomb sample produced from LDPE/HDPE bicomponent fiber was close to compression strength test result of the PLA honeycomb sample. The results revelaled that LDPE/HDPE bicomponent fibers could be an alternative to PLA fiber in 3D printing technologies.

scholarly journals Hydrogen bond-reinforced double-network hydrogels with ultrahigh elastic modulus and shape memory property

2018 ◽  
Vol 56 (19) ◽  
pp. 1281-1286 ◽  
Author(s):  
Yan Jie Wang ◽  
Chen Yu Li ◽  
Zhi Jian Wang ◽  
Yiping Zhao ◽  
Li Chen ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Elastic Modulus ◽  
Shape Memory ◽  
Shape Memory Property ◽  
Double Network ◽  
Memory Property

Effect of Silica Fume on Mechanical Properties and Carbonation Resistance of Concrete

2012 ◽  
Vol 238 ◽  
pp. 161-164 ◽  
Author(s):  
Qing Long Wang ◽  
Jun Chao Bao
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Elastic Modulus ◽  
Silica Fume ◽  
Compression Strength ◽  
Considerable Increase ◽  
Carbonation Resistance

A designed experimental study has been conducted to investigate the effect of silica fume on mechanical properties and carbonation resistance of concrete, a large number of experiments have been carried out in this study. The results indicate that the addition of silica fume has improved the compression strength and elastic modulus of concrete. A considerable increase for the compression strength and elastic modulus of the concrete was observed by increasing the dosage of silica fume. Besides, the addition of silica fume can improve the carbonation resistance of the concrete composite evidently, and the carbonation resistance is becoming better and better as the silica fume content is increasing gradually.

scholarly journals Concrete with Reused Concrete Sand

2019 ◽  
Vol 8 (6) ◽  
pp. 4868-4873
Keyword(s):  
Elastic Modulus ◽  
Compression Strength ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Ordinary Concrete ◽  
Mixed Concrete

This paper examines the impacts of substitution of reused concrete sand (RCS) with sands, on the new and hardened physiognomies of concrete. the property of RCS blended concrete was examined and likened with ordinary concrete of 40 MPa compression strength. the physiognomies of RCS concrete vary from ordinary concrete arranged with characteristic sand, as an outcome of the quality of connected mortar, old cement glue, and more fines. the outcomes demonstrate that the RCS concrete demonstrations tantamount workability in contrast with ordinary concrete. the mechanical physiognomies (compressive, flexure, split tensile and elastic modulus) of concrete developed with RCS was lower in compression to ordinary concrete however worthy up to 60percentage RCS in the blend. The drying shrinkage strain of 100percentage RCC mixed concrete at twenty-eight days was watched twice in compression to controlled concrete and it demonstrated more abrasion value in that comparison and furthermore concrete developed with 100 percent RCS indicated 41percentage and 11.3percentage lower in sorption value at ahead of schedule and later age organize individually in that examination.

scholarly journals Experimental Study on Physical-mechanical Properties and Fracture Behaviors of Saturated Yellow Sandstone Considering Coupling Effect of Freeze-Thaw and Specimen Inclination

2020 ◽  
Vol 12 (3) ◽  
pp. 1029 ◽  
Author(s):  
Liang Chen ◽  
Peng Wu ◽  
Yanlong Chen ◽  
Wei Zhang
Keyword(s):  
Mechanical Properties ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Failure Mode ◽  
Inclination Angle ◽  
Compression Strength ◽  
Shear Loading ◽  
Cold Regions ◽  
Freeze Thaw ◽  
Peak Compression

The effect of freeze-thaw on the physical-mechanical properties and fracture behavior of rock under combined compression and shear loading was crucial for revealing the instability mechanism and optimizing the structure design of rock engineering in cold regions. However, there were few reports on the failure behavior of rock treated by freeze-thaw under combined compression and shear loading due to the lack of test equipment. In this work, a novel combined compression and shear test (C-CAST) system was introduced to carry out a series of uniaxial compression tests on saturated yellow sandstone under various inclination angles (θ = 0°, 5°, 10°, and 15°) and the number of freeze-thaw cycles (N = 0, 20, 40, and 60). The test results showed that the P-wave velocity dramatically decreased, while the rock quality and porosity increased gradually as N increased; the peak compression strength and elastic modulus obviously decreased with the increasing θ and N, while the peak shear stress increased gradually with the increasing θ and decreased with the increase of N, indicating that the shear stress component can accelerate the crack propagation and reduce its resistance to deformation. The acoustic emission (AE) results revealed that the change of crack initiation (CI) stress and crack damage (CD) stress with the θ and N had a similar trend as that of the peak compression strength and elastic modulus. Particularly, the CI and CD thresholds at 60 cycles were only 81.31% and 84.47% of that at 0° cycle and indicated a serious freeze-thaw damage phenomenon, which was consistent with the results of scanning electron microscopy (SEM) with the appearance of some large-size damage cracks. The fracture mode of sandstone was dependent on the inclination angle. The failure mode developed from both the tensile mode (0°) and combined tensile-shear mode (5°) to a pure shear failure (10°–15°) with the increasing inclination angle. Meanwhile, the freeze-thaw cycle only had an obvious effect on the failure mode of the specimen at a 5° inclination. Finally, a novel multivariate regression analysis method was used to predict the peak compression strength and elastic modulus based on the initial strength parameters (θ = 0°, N = 0). The study results can provide an important reference for the engineering design of rock subjected to a complex stress environment in cold regions.

scholarly journals 3D Printing of PLA/clay Nanocomposites: Influence of Printing Temperature on Printed Samples Properties

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1947 ◽  
Author(s):  
Bartolomeo Coppola ◽  
Nicola Cappetti ◽  
Luciano Di Maio ◽  
Paola Scarfato ◽  
Loredana Incarnato
Keyword(s):  
Elastic Modulus ◽  
3D Printing ◽  
Layered Silicate ◽  
Tensile Tests ◽  
Nucleating Agent ◽  
Clay Nanocomposites ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Dog Bone ◽  
3D Printed

In this study, the possibility of using a layered silicate-reinforced polylactic acid (PLA) in additive manufacturing applications was investigated. In particular, the aim of this work was to study the influence of printing temperature in the 3D printing process of PLA/clay nanocomposites. For this reason, two PLA grades (4032D and 2003D, D-isomer content 1.5 and 4, respectively) were melt-compounded by a twin screw extruder with a layered silicate (Cloisite 30B) at 4 wt %. Then, PLA and PLA/clay feedstock filaments (diameter 1.75 mm) were produced using a single screw extruder. Dog-bone and prismatic specimens were 3D printed using the FDM technique at three different temperatures, which were progressively increased from melting temperature (185–200–215 °C for PLA 4032D and 165–180–195 °C for PLA 2003D). PLA and PLA/clay specimens were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and tensile tests. Moreover, the morphology of the 3D printed specimens was investigated using optical microscopy and contact angle measurements. The different polymer matrix and the resulting nanocomposite morphology strongly influenced 3D printed specimen properties. DMA on PLA/clay filaments reported an increase in storage modulus both at ambient temperature and above the glass transition temperature in comparison to neat PLA filaments. Furthermore, the presence of nanoclay increased thermal stability, as demonstrated by TGA, and acted as a nucleating agent, as observed from the DSC measurements. Finally, for 3D printed samples, when increasing printing temperature, a different behavior was observed for the two PLA grades and their nanocomposites. In particular, 3D printed nanocomposite samples exhibited higher elastic modulus than neat PLA specimens, but for PLA 4032D+C30B, elastic modulus increased at increasing printing temperature while for PLA 2003D+C30B slightly decreased. Such different behavior can be explained considering the different polymer macromolecular structure and the different nanocomposite morphology (exfoliated in PLA 4032D matrix and intercalated in PLA 2003D matrix).

scholarly journals 3D Printing of Strong and Tough Double Network Granular Hydrogels

2020 ◽  
pp. 2005929
Author(s):  
Matteo Hirsch ◽  
Alvaro Charlet ◽  
Esther Amstad
Keyword(s):  
3D Printing ◽  
Double Network

The relation between porosity, microstructure and strength, and the approach to advanced cement-based materials

1983 ◽  
Vol 310 (1511) ◽  
pp. 139-153 ◽  
Keyword(s):  
Elastic Modulus ◽  
Fracture Energy ◽  
Cement Paste ◽  
Compression Strength ◽  
Bending Strength ◽  
Cement Pastes ◽  
Cement Based Materials ◽  
Mdf Cements

A theory is formulated to connect the strength of cement paste with its porosity. The theory shows that bending strength is largely dictated by the length of the largest pores, as in the Griffith (1920) model, but there is also an influence of the volume of porosity, which affects toughness through changing elastic modulus and fracture energy. Verification of this theory was achieved by observing the large pores in cement, and then relating bending strength to the measured defect length, modulus and fracture energy. The argument was proved by developing processes to remove the large pores from cement pastes, thereby raising the bending strength to 70 MPa. Further removal of colloidal pores gave a bending strength of 150 MPa and compression strength up to 300 MPa with improved toughness. Re-introduction of controlled pores into these macro-defect-free (mdf) cements allowed Feret’s law (1897) to be explained.

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