scholarly journals Flexural Behavior of 3D printed Concrete Beam with Fiber Reinforcement

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Ghassan K Al-Chaar ◽  
Andrij Kozych
Keyword(s):  
Concrete Beam ◽  
Low Cost ◽  
Flexural Behavior ◽  
Flexure Strength ◽  
Steel Rebar ◽  
Maximum Flexure ◽  
Reinforced Beams ◽  
Cast Concrete ◽  
3D Printed ◽  
Steel Rebars

3D printing with concrete is a promising new method for rapid, low cost construction. The flexural strengths for reinforced/unreinforced and 3D printed/cast concrete Warren trusses were tabulated and the failure mechanisms were reported. The types of reinforcement used were rebar(basalt and steel), and mesh (basalt and aramid). The effect of loading geometry and loading speed  was measured for basalt mesh and aramid mesh composite, respectively. Due to the expected variation in flexure between samples, it cannot be said whether small differences for various tests are significant. Variation stems from a microscopically uneven surface and random inhomogeneities in the bulk of the tested material which act as a microcrack catalyst and propagator. Since the tested beams are short specimens the numerical findings of other studies will vary based on the intended design. This paper is intended to assess the performance of various reinforcements in a qualitative sense by comparing basalt reinforcement with other reinforcements.  It was found that cast beams tolerated deflection better but had a similar flexure strength compared as the printed beams. The steel and basalt rebar reinforced beams had the highest flexure strengths where the traditional steel rebar reinforcement outperformed the basalt in flexure by 36% and the basalt outperformed the steel in deflection by 40%.  The basalt mesh outperformed the cast and printed unreinforced bars by a small margin but had only 25% of steel rebars’ deflection at maximum flexure strength. The aramid mesh tolerated the biggest deflection out of any sample at 2.26 cm.

Experimental Research on Bending Performance of Concrete Beams Reinforced with CFRP-PCPs Composite Rebars

2013 ◽  
Vol 438-439 ◽  
pp. 804-806
Author(s):  
Jiong Feng Liang ◽  
Jian Bao Wang ◽  
Jian Ping Li
Keyword(s):  
Experimental Research ◽  
Prestressed Concrete ◽  
Crack Width ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Bending Performance ◽  
Reinforced Beams

The flexural behavior of concrete beams reinforced with CFRP-PCPs composite rebars was studied. Experimental results showed that the deflection of beams reinforced with highly prestressed prisms is at service loads coMParable to deflection of steel reinforced beam. Flexural cracks of CFRP-PCPs composite rebars reinforced beams are hairline before prism cracking, and widened after the prism cracking. When the concrete beam was reinforced with the prestressed concrete prisms, the crack width decreased as the prestress in the prism increased.

scholarly journals Low-Cycle Flexural Fatigue Behavior of Concrete Beam Reinforced with Hybrid FRP-Steel Rebar

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jinkyo F. Choo ◽  
Young-Cheol Choi ◽  
Seung-Jun Kwon ◽  
Ki-Tae Park ◽  
Sung-Won Yoo
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beam ◽  
Flexural Behavior ◽  
Fatigue Cycle ◽  
Flexural Fatigue ◽  
Steel Rebar

Studies examined experimentally the flexural behavior of concrete beams reinforced with the hybrid FRP-steel rebar but very few among them evaluated their fatigue performance. In this study, the fatigue test has been performed, and an analytical model for simulating the flexural fatigue behavior of the concrete beam reinforced with the hybrid bar considering its postyielding behavior is developed. A formula relating the postyielding fatigue strain of the rebar to the number of the fatigue cycle is suggested and used in the proposed procedure. The method simulating the low-cycle behavior of the reinforced concrete beam is found to be satisfactory and can predict the number of cyclic loading to failure.

Pioneering Low-Cost 3D-Printed Transtibial Prosthetics to Serve a Rural Population in Sierra Leone

2020 ◽  
Author(s):  
Merel van der Stelt ◽  
Martin P. Grobusch ◽  
Abdul R. Koroma ◽  
Marco Papenburg ◽  
Ismaila Kebbie ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Rural Population ◽  
Low Cost ◽  
3D Printed

scholarly journals UV Inscription and Pressure Induced Long-Period Gratings through 3D Printed Amplitude Masks

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1977
Author(s):  
Ricardo Oliveira ◽  
Liliana M. Sousa ◽  
Ana M. Rocha ◽  
Rogério Nogueira ◽  
Lúcia Bilro
Keyword(s):  
State Of The Art ◽  
Low Cost ◽  
Resonance Wavelength ◽  
Complex Structures ◽  
Pressing Method ◽  
Long Period ◽  
Long Period Gratings ◽  
3D Printed ◽  
Mechanical Pressing ◽  
First Time

In this work, we demonstrate for the first time the capability to inscribe long-period gratings (LPGs) with UV radiation using simple and low cost amplitude masks fabricated with a consumer grade 3D printer. The spectrum obtained for a grating with 690 µm period and 38 mm length presented good quality, showing sharp resonances (i.e., 3 dB bandwidth < 3 nm), low out-of-band loss (~0.2 dB), and dip losses up to 18 dB. Furthermore, the capability to select the resonance wavelength has been demonstrated using different amplitude mask periods. The customization of the masks makes it possible to fabricate gratings with complex structures. Additionally, the simplicity in 3D printing an amplitude mask solves the problem of the lack of amplitude masks on the market and avoids the use of high resolution motorized stages, as is the case of the point-by-point technique. Finally, the 3D printed masks were also used to induce LPGs using the mechanical pressing method. Due to the better resolution of these masks compared to ones described on the state of the art, we were able to induce gratings with higher quality, such as low out-of-band loss (0.6 dB), reduced spectral ripples, and narrow bandwidths (~3 nm).

scholarly journals BoSL FAL Pump: a small, low-cost, easily constructed, 3D-printed peristaltic pump for sampling of waters

HardwareX ◽  
2021 ◽  
pp. e00214
Author(s):  
David T. McCarthy ◽  
Baiqian Shi ◽  
Miao Wang ◽  
Stephen Catsamas
Keyword(s):  
Low Cost ◽  
Peristaltic Pump ◽  
3D Printed

Using low-cost 3D-printed models of prenatal ultrasonography for visually-impaired expectant persons

2021 ◽  
Author(s):  
Romain Nicot ◽  
Edwige Hurteloup ◽  
Sébastien Joachim ◽  
Charles Druelle ◽  
Jean-Marc Levaillant
Keyword(s):  
Visually Impaired ◽  
Low Cost ◽  
Prenatal Ultrasonography ◽  
3D Printed

scholarly journals Microstructured Surface Plasmon Resonance Sensor Based on Inkjet 3D Printing Using Photocurable Resins with Tailored Refractive Index

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2518
Author(s):  
Nunzio Cennamo ◽  
Lorena Saitta ◽  
Claudio Tosto ◽  
Francesco Arcadio ◽  
Luigi Zeni ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
3D Printing ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Optical Sensor ◽  
Low Cost ◽  
3D Print ◽  
Spr Sensor ◽  
Resonance Sensor ◽  
3D Printed

In this work, a novel approach to realize a plasmonic sensor is presented. The proposed optical sensor device is designed, manufactured, and experimentally tested. Two photo-curable resins are used to 3D print a surface plasmon resonance (SPR) sensor. Both numerical and experimental analyses are presented in the paper. The numerical and experimental results confirm that the 3D printed SPR sensor presents performances, in term of figure of merit (FOM), very similar to other SPR sensors made using plastic optical fibers (POFs). For the 3D printed sensor, the measured FOM is 13.6 versus 13.4 for the SPR-POF configuration. The cost analysis shows that the 3D printed SPR sensor can be manufactured at low cost (∼15 €) that is competitive with traditional sensors. The approach presented here allows to realize an innovative SPR sensor showing low-cost, 3D-printing manufacturing free design and the feasibility to be integrated with other optical devices on the same plastic planar support, thus opening undisclosed future for the optical sensor systems.

scholarly journals Induction of Neural Plasticity Using a Low-Cost Open Source Brain-Computer Interface and a 3D-Printed Wrist Exoskeleton

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 572
Author(s):  
Mads Jochumsen ◽  
Taha Al Muhammadee Janjua ◽  
Juan Carlos Arceo ◽  
Jimmy Lauber ◽  
Emilie Simoneau Buessinger ◽  
...  
Keyword(s):  
Open Source ◽  
Neural Plasticity ◽  
Motor Evoked Potentials ◽  
Low Cost ◽  
True Positive Rate ◽  
Positive Rate ◽  
3D Printed ◽  
Major Factors ◽  
And Control ◽  
Bci System

Brain-computer interfaces (BCIs) have been proven to be useful for stroke rehabilitation, but there are a number of factors that impede the use of this technology in rehabilitation clinics and in home-use, the major factors including the usability and costs of the BCI system. The aims of this study were to develop a cheap 3D-printed wrist exoskeleton that can be controlled by a cheap open source BCI (OpenViBE), and to determine if training with such a setup could induce neural plasticity. Eleven healthy volunteers imagined wrist extensions, which were detected from single-trial electroencephalography (EEG), and in response to this, the wrist exoskeleton replicated the intended movement. Motor-evoked potentials (MEPs) elicited using transcranial magnetic stimulation were measured before, immediately after, and 30 min after BCI training with the exoskeleton. The BCI system had a true positive rate of 86 ± 12% with 1.20 ± 0.57 false detections per minute. Compared to the measurement before the BCI training, the MEPs increased by 35 ± 60% immediately after and 67 ± 60% 30 min after the BCI training. There was no association between the BCI performance and the induction of plasticity. In conclusion, it is possible to detect imaginary movements using an open-source BCI setup and control a cheap 3D-printed exoskeleton that when combined with the BCI can induce neural plasticity. These findings may promote the availability of BCI technology for rehabilitation clinics and home-use. However, the usability must be improved, and further tests are needed with stroke patients.

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