scholarly journals Experimental Study on the Fracture Evolution Processof Rock-like Specimens Containing a Closed RoughJoint Based on 3D-Printing Technology

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Jiawei Liu ◽  
Haijian Su ◽  
Hongwen Jing ◽  
Chengguo Hu ◽  
Qian Yin
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Failure Mode ◽  
Shear Failure ◽  
Rock Joints ◽  
Image Correlation ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Joint Inclination ◽  
Joint Length

In order to overcome the disadvantage of traditional joint fabrication method—inability to reproduce the rough surfaces of practical rock joints—3D-printing technology was applied to restructure five kinds of rough joint according to the failure surface formed by the triaxial prepeak unloading test in this study. And uniaxial compression test was carried out on the rock-like specimens containing closed 3D-printing rough joint to study the effects of joint inclination and joint length on the mechanical properties (peak strength, peak strain, elastic modulus, and secant modulus), cracking process, and failure modes. Besides, digital image correlation (DIC) method and acoustic emission (AE) system are used to investigate the whole evolution process of strain fields and crack propagation during loading. It is found that the mechanical parameters decrease first and then go up as the joint inclination increases, while presenting a continuous downward trend with the increase of joint length. Inclination of 45° and the larger joint length bring more extensive reduction to mechanical properties of specimens. Specimens exhibit typical brittle failure characteristics. The failure mode of specimens affected by different joint inclination is tension-shear failure. And the joint scale rises; the failure mode of specimens changes from tensile failure to shear failure. Larger joint scale results in the longer prepeak fluctuation phase on axial stress-strain curves and more dispersed distribution of high-value AE counts.

scholarly journals Possible Applications of Additive Manufacturing Technologies in Shipbuilding: A Review

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 84
Author(s):  
Marcin Ziółkowski ◽  
Tomasz Dyl
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Weight Reduction ◽  
Maritime Industry ◽  
High Quality ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Manufacturing Technologies ◽  
Very High

3D printing conquers new branches of production due to becoming a more reliable and professional method of manufacturing. The benefits of additive manufacturing such as part optimization, weight reduction, and ease of prototyping were factors accelerating the popularity of 3D printing. Additive manufacturing has found its niches, inter alia, in automotive, aerospace and dentistry. Although further research in those branches is still required, in some specific applications, additive manufacturing (AM) can be beneficial. It has been proven that additively manufactured parts have the potential to out perform the conventionally manufactured parts due to their mechanical properties; however, they must be designed for specific 3D printing technology, taking into account its limitations. The maritime industry has a long-standing tradition and is based on old, reliable techniques; therefore it implements new solutions very carefully. Besides, shipbuilding has to face very high classification requirements that force the use of technologies that guarantee repeatability and high quality. This paper provides information about current R&D works in the field of implementing AM in shipbuilding, possible benefits, opportunities and threats of implementation.

Nano Mechanical Properties of Ceramic Polymer Composite Micro Thruster Developed Using 3D Printing Technology

2018 ◽  
Vol 24 (8) ◽  
pp. 5884-5890 ◽  
Author(s):  
Pravin Khandekar ◽  
Kanishka Biswas ◽  
Dushyant Kothari ◽  
H Muthurajan
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Polymer Composite ◽  
Small Angle ◽  
Large Deviation ◽  
Mems Devices ◽  
Long Distance ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Specific Direction

Nano and micro satellites, when revolving around the earth, may drift by very small angle from their orbit. But this small angle drift may result in large deviation from their original orbit over a long distance which these satellite covers over a period of time. For the course correction of these satellites, very small thrust is required in specific direction. Normal propulsion system cannot serve this purpose, because the thrust may be too large for these satellites. That’s where the role of micro thrusters becomes important. These are MEMS devices which can produce very small thrust and can be used for nano and micro satellite propulsion. In this study, we have developed micro thrusters using 3D printing technology from ceramic polymer composite. They have been characterized for different nano mechanical properties to study their suitability for propelling the nano and micro satellite.

scholarly journals Effects of Carbonyl Iron Powder (CIP) Content on the Electromagnetic Wave Absorption and Mechanical Properties of CIP/ABS Composites

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1694
Author(s):  
Wenwen Lai ◽  
Yan Wang ◽  
Junkun He
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Wave ◽  
3D Printing ◽  
Iron Powder ◽  
Carbonyl Iron ◽  
Functional Material ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Fused Deposition ◽  
Carbonyl Iron Powder

Three-dimensional (3D) printing technology has proven to be a convenient and effective method to fabricate structural electromagnetic wave (EMW) absorbers with tunable EMW absorption properties. To obtain a functional material with strong EMW absorbing performance and excellent mechanical properties for fused deposition modeling (FDM) 3D printing technology, in this work, carbonyl iron powder (CIP)/acrylonitrile-butadiene-styrene copolymer (ABS) composites with different CIP contents were prepared by the melt-mixing process. The effects of the CIP content on the EMW absorption and mechanical properties of CIP/ABS composites were investigated. The CIP/ABS composite with a CIP content of 40 wt.% presented the lowest reflection loss (RL) of −48.71 dB for the optimal impedance matching. In addition, this composite exhibited optimal mechanical properties due to the good dispersion of the CIPs in the matrix ABS. Not only were the tensile and flexural strength similar to pure ABS, but the tensile and flexural modulus were 32% and 37% higher than those of pure ABS, respectively. With a CIP content of 40 wt.%, the CIP/ABS composite proved to be a novel functional material with excellent EMW absorbing and mechanical properties, providing great potential for the development of structural absorbers via FDM 3D printing technology.

scholarly journals Testing of mechanical properties of materials used in FDM technology

Mechanik ◽  
2019 ◽  
Vol 92 (4) ◽  
pp. 285-287 ◽  
Author(s):  
Marcin Snopczyński ◽  
Jarosław Kotliński ◽  
Ireneusz Musiałek
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
3D Printing ◽  
Strength Parameters ◽  
Full Data ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials ◽  
Materials Used

With the development of 3D printing technology, there is a development in the use of new printing materials. In practice, it often happens that the constructor does not have full data about the material that he wants to use. The article presents the results of tests of tensile strength of samples printed using the FDM method. 3D printing using the FDM method is widespread, however, the properties of the materials used in this method are still not fully understood. The aim of the research was to obtain information on strength parameters that form the basis for further analyzes.

Experiment of Mechanical Properties of a Customized Distractor Based on 3D Printing Technology

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Xinran Zhao ◽  
Guangwei Li ◽  
Guofang Shen ◽  
Jianhe Wei ◽  
Ming Cai
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Printing Technology ◽  
3D Printing Technology

Thermoplastic polyurethanes for mining application processing by 3D printing

2019 ◽  
Vol 1 (95) ◽  
pp. 13-19
Author(s):  
M. Mrówka ◽  
M. Szymiczek ◽  
J. Lenża
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mine Water ◽  
Aging Process ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Printing Technology ◽  
Thermoplastic Polyurethanes ◽  
3D Printing Technology ◽  
Static Tensile

Purpose: Thermoplastic polyurethanes (TPU) found application in mining. Due to the excellent processing properties, thermoplastic polyurethanes can be also use to make elements that would facilitate miner's work. These elements, however, differ in dimensions depending on the person who is going to use them, that is why they should be personalized. In case of all the above studies, the elements or stuffs were made by means of the injection method. This method limits the possibility of producing mining’s stuff only to models that have a mould. The 3D printing technology developing rapidly throughout the recent years allows for high-precision, personalized elements’ printing, made of thermoplastic materials. Design/methodology/approach: The samples from thermoplastic polyurethanes were made using 3D printing and then subjected to the aging process at intervals of 2, 7 and 30 days. The samples were then subjected to a static tensile tests, hardness tests and FT-IR spectroscopy. Findings: The obtained results of mechanical tests and IR analyses show that the aging process in mine water does not affect the mechanical properties of the samples regardless of the aging time. IR spectral analysis showed no changes in the structure of the main and side polyurethane chains. Both mechanical and spectral tests prove that polyurethanes processed using 3D printing technology can be widely used in mining. Research limitations/implications: Only one type of TPU was processed in this work. Further work should show that synthetic mine water does not degrade the mechanical properties of other commercially available TPUs. Practical implications: The additive technology allows getting elements of mining clothing, ortheses, insoles or exoskeleton elements adapted to one miner. Originality/value: The conducted tests allowed to determine no deterioration of the mechanical properties of samples aged in synthetic mine water. TPU processing using 3D printing technology can be used in mining.

scholarly journals Characterization and Preliminary Biological Evaluation of 3D-Printed Porous Scaffolds for Engineering Bone Tissues

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1832 ◽  
Author(s):  
Chen-Guang Liu ◽  
Yu-Ting Zeng ◽  
Ranjith Kankala ◽  
Shan-Shan Zhang ◽  
Ai-Zheng Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Bone Cells ◽  
Evaluation Studies ◽  
Critical Evaluation ◽  
Biological Evaluation ◽  
Porous Scaffolds ◽  
3D Scaffolds ◽  
Printing Technology ◽  
3D Printing Technology

Some basic requirements of bone tissue engineering include cells derived from bone tissues, three-dimensional (3D) scaffold materials, and osteogenic factors. In this framework, the critical architecture of the scaffolds plays a crucial role to support and assist the adhesion of the cells, and the subsequent tissue repairs. However, numerous traditional methods suffer from certain drawbacks, such as multi-step preparation, poor reproducibility, high complexity, difficulty in controlling the porous architectures, the shape of the scaffolds, and the existence of solvent residue, which limits their applicability. In this work, we fabricated innovative poly(lactic-co-glycolic acid) (PLGA) porous scaffolds, using 3D-printing technology, to overcome the shortcomings of traditional approaches. In addition, the printing parameters were critically optimized for obtaining scaffolds with normal morphology, appropriate porous architectures, and sufficient mechanical properties, for the accommodation of the bone cells. Various evaluation studies, including the exploration of mechanical properties (compressive strength and yield stress) for different thicknesses, and change of structure (printing angle) and porosity, were performed. Particularly, the degradation rate of the 3D scaffolds, printed in the optimized conditions, in the presence of hydrolytic, as well as enzymatic conditions were investigated. Their assessments were evaluated using the thermal gravimetric analyzer (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). These porous scaffolds, with their biocompatibility, biodegradation ability, and mechanical properties, have enabled the embryonic osteoblast precursor cells (MC3T3-E1), to adhere and proliferate in the porous architectures, with increasing time. The generation of highly porous 3D scaffolds, based on 3D printing technology, and their critical evaluation, through various investigations, may undoubtedly provide a reference for further investigations and guide critical optimization of scaffold fabrication, for tissue regeneration.

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