scholarly journals Early-Age Mechanical Properties of 3D-Printed Mortar with Spent Garnet

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 100
Author(s):  
Szymon Skibicki ◽  
Patrycja Jakubowska ◽  
Maria Kaszyńska ◽  
Daniel Sibera ◽  
Krzysztof Cendrowski ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Cementitious Materials ◽  
Hydraulic Press ◽  
Image Analysis System ◽  
Natural Sand ◽  
Green Strength ◽  
Binder Ratio ◽  
3D Printed ◽  
Analysis System

This study determines the effect of spent garnet as a replacement for natural sand in 3D-printed mortar at early ages. Five mixes with different spent garnet amounts were prepared (0%, 25%, 50%, 75% and 100% by volume). The ratio of binder to aggregate remained unchanged. In all mixes the water/binder ratio was assumed as a constant value of 0.375. Tests were performed to confirm the printability of the mix (a path quality test using a gantry robot with an extruder). Determinations of key buildability properties of the mix (green strength and Young’s Modulus) during uniaxial compressive strength at 15 min, 30 min and 45 min after adding water were conducted. A hydraulic press and the GOM ARAMIS precision image analysis system were used to conduct the study. The results showed that an increase in spent garnet content caused a decrease in green strength and Young’s Modulus (up to 69.91% and 80.37%, respectively). It was found that to maintain proper buildability, the recommended maximum replacement rate of natural sand with garnet is 50%. This research contributes new knowledge in terms of using recycled waste in the 3D printing technology of cementitious materials.

scholarly journals Relationship between Quadriceps Tendon Young’s Modulus and Maximum Knee Flexion Angle in the Swing Phase of Gait in Patients with Severe Knee Osteoarthritis

Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 437
Author(s):  
Bungo Ebihara ◽  
Takashi Fukaya ◽  
Hirotaka Mutsuzaki
Keyword(s):  
Young’S Modulus ◽  
Gait Speed ◽  
Knee Flexion ◽  
Young's Modulus ◽  
Quadriceps Tendon ◽  
Swing Phase ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Knee Oa ◽  
Analysis System

Background and objectives: Decreased knee flexion in the swing phase of gait can be one of the causes of falls in severe knee osteoarthritis (OA). The quadriceps tendon is one of the causes of knee flexion limitation; however, it is unclear whether the stiffness of the quadriceps tendon affects the maximum knee flexion angle in the swing phase. The purpose of this study was to clarify the relationship between quadriceps tendon stiffness and maximum knee flexion angle in the swing phase of gait in patients with severe knee OA. Materials and Methods: This study was conducted from August 2018 to January 2020. Thirty patients with severe knee OA (median age 75.0 (interquartile range 67.5–76.0) years, Kellgren–Lawrence grade: 3 or 4) were evaluated. Quadriceps tendon stiffness was measured using Young’s modulus by ShearWave Elastography. The measurements were taken with the patient in the supine position with the knee bent at 60° in a relaxed state. A three-dimensional motion analysis system measured the maximum knee flexion angle in the swing phase. The measurements were taken at a self-selected gait speed. The motion analysis system also measured gait speed, step length, and cadence. Multiple regression analysis by the stepwise method was performed with maximum knee flexion angle in the swing phase as the dependent variable. Results: Multiple regression analysis identified quadriceps tendon Young’s modulus (standardized partial regression coefficients [β] = −0.410; p = 0.013) and gait speed (β = 0.433; p = 0.009) as independent variables for maximum knee flexion angle in the swing phase (adjusted coefficient of determination = 0.509; p < 0.001). Conclusions: Quadriceps tendon Young’s modulus is a predictor of the maximum knee flexion angle. Clinically, decreasing Young’s modulus may help to increase the maximum knee flexion angle in the swing phase in those with severe knee OA.

scholarly journals Mechanical Properties and Environmental Evaluation of Ultra-High-Performance Concrete with Aeolian Sand

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3148 ◽  
Author(s):  
Hongyan Chu ◽  
Fengjuan Wang ◽  
Liguo Wang ◽  
Taotao Feng ◽  
Danqian Wang
Keyword(s):  
Compressive Strength ◽  
Environmental Impact ◽  
Young’S Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Young's Modulus ◽  
Ultra High Performance Concrete ◽  
Aeolian Sand ◽  
Binder Ratio ◽  
Water Binder Ratio

Ultra-high-performance concrete (UHPC) has received increasing attention in recent years due to its remarkable ductility, durability, and mechanical properties. However, the manufacture of UHPC can cause serious environmental issues. This work addresses the feasibility of using aeolian sand to produce UHPC, and the mix design, environmental impact, and mechanical characterization of UHPC are investigated. We designed the mix proportions of the UHPC according to the modified Andreasen and Andersen particle packing model. We studied the workability, microstructure, porosity, mechanical performance, and environmental impact of UHPC with three different water/binder ratios. The following findings were noted: (1) the compressive strength, flexural strength, and Young’s modulus of the designed UHPC samples were in the ranges of 163.9–207.0 MPa, 18.0–32.2 MPa, and 49.3–58.9 GPa, respectively; (2) the compressive strength, flexural strength, and Young’s modulus of the UHPC increased with a decrease in water/binder ratio and an increase in the steel fibre content; (3) the compressive strength–Young’s modulus correlation of the UHPC could be described by an exponential formula; (4) the environmental impact of UHPC can be improved by decreasing its water/binder ratio. These findings suggest that it is possible to use aeolian sand to manufacture UHPC, and this study promotes the application of aeolian sand for this purpose.

Measurement of Young's modulus of cementitious materials using an electro-optic holographic technique

2001 ◽  
Vol 36 (6) ◽  
pp. 527-535 ◽  
Author(s):  
Rolando González-Peña ◽  
Luis Martı́-López ◽  
Rosa M. Cibrián-Ortiz de Anda ◽  
Teresa Molina-Jiménez ◽  
Carlos Piqueres-Ayela
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Cementitious Materials ◽  
Electro Optic

scholarly journals Experimental Study of Hardened Young’s Modulus for 3D Printed Mortar

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7643
Author(s):  
Szymon Skibicki ◽  
Mateusz Techman ◽  
Karol Federowicz ◽  
Norbert Olczyk ◽  
Marcin Hoffmann
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Statistical Correlation ◽  
Test Methods ◽  
Cylindrical Sample ◽  
Experimental Investigations ◽  
Current Standard ◽  
Number Of Layers ◽  
3D Printed

Few studies have focused on determining the Young’s modulus of 3D printed structures. This study presents the results of experimental investigations of Young’s modulus of a 3D printed mortar. Specimens were prepared in four different ways to investigate possible application of different methods for 3D printed structures. Study determines the influence of the number of layers on mechanical properties of printed samples. Results have shown a strong statistical correlation between the number of layers and value of Young’s modulus. The compressive strength and Young’s modulus reduction compared to standard cylindrical sample were up to 43.1% and 19.8%, respectively. Results of the study shed light on the differences between the current standard specimen used for determination of Young’s modulus and the specimen prepared by 3D printing. The community should discuss the problem of standardization of test methods in view of visible differences between different types of specimens.

scholarly journals Inverse Identification Of Elastic Moduli For 3D Printed PLA, Using Impulse Excitation Technique (IET)

2021 ◽  
Author(s):  
Afridi Mohsin
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bulk Material ◽  
Dynamic Properties ◽  
Test Results ◽  
Young’S Moduli ◽  
Vibration Experiment ◽  
3D Printed ◽  
Printed Materials

3D Printing has recently undergone extensive development due to its lower cost and flexibility. A number of studies have been carried out to determine 3D printed material properties. This study focuses on the determination of the dynamic properties for PLA. The PLA material is processed through the popular FDM method with three different build orientations. A vibration experiment is conducted to evaluate the first modal frequency and Young’s modulus. The results are then compared to the FEM modal analysis and finally the traditional tensile testing results. The anisotropy of the 3D printed components, mainly due to the density changes caused by voids and filament alignment, result in the variation of the Young’s modulus which is different than the homogenous bulk material. The calculated Young’s moduli values are very slightly higher than the tensile test results which is in conformance with the trend documented by earlier studies on similar printed materials using the same techniques

3D printable light-responsive polymers

2017 ◽  
Vol 4 (3) ◽  
pp. 396-401 ◽  
Author(s):  
I. Roppolo ◽  
A. Chiappone ◽  
A. Angelini ◽  
S. Stassi ◽  
F. Frascella ◽  
...  
Keyword(s):  
3D Printing ◽  
Laser Irradiation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Polymeric Matrices ◽  
Responsive Polymers ◽  
3D Printed

New photo-curable polymers suitable for 3D printing are here provided, exhibiting a mechanical light-responsivity upon laser irradiation. Azobenzene moieties are employed both as a dye component in the 3DP and as active groups, providing photo-mechanical responsivity. The incorporation of azobenzene units into polymeric matrices allows a reversible and controllable change of the Young's modulus of 3D printed micrometric structures.

scholarly journals Degradation of 3D-Printed Porous Polylactic Acid Scaffolds Under Mechanical Stimulus

2021 ◽  
Vol 9 ◽  
Author(s):  
Heming Chen ◽  
Quan Shi ◽  
Hengtao Shui ◽  
Peng Wang ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Numerical Model ◽  
Young’S Modulus ◽  
Polylactic Acid ◽  
Young's Modulus ◽  
Average Molecular Weight ◽  
Mechanical Stimulus ◽  
Number Average Molecular Weight ◽  
3D Printed

Polylactic acid (PLA) is a biodegradable polymer commonly used as a scaffold material to repair tissue defects, and its degradation is associated with mechanical stimulus. In this study, the effect of mechanical stimulus on the degradation of 3D-printed PLA scaffolds was investigated by in vitro experiments and an author-developed numerical model. Forty-five samples with porosity 64.8% were printed to carry out the degradation experiment within 90 days. Statistical analyses of the mass, volume fraction, Young’s modulus, and number average molecular weight were made, and the in vitro experiments were further used to verify the proposed numerical model of the scaffold degradation. The results indicated that the mechanical stimulus accelerated the degradation of the PLA scaffold, and the higher mechanical stimulus led to a faster degradation of the scaffolds at the late stage of the degradation process. In addition, the Young’s modulus and the normalized number average molecular weight of the PLA scaffolds between the experiments and the numerical simulations were comparable, especially for the number average molecular weight. The present study could be helpful in the design of the biodegradable PLA scaffolds.

Study of Printing Orientation on Mechanical Properties in Additive Manufacturing Process

2019 ◽  
Author(s):  
Peyman Honarmandi ◽  
Hongbin Xu
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Young’S Modulus ◽  
Manufacturing Process ◽  
Young's Modulus ◽  
Innovative Technology ◽  
Build Orientation ◽  
Fused Deposition ◽  
3D Printed

Abstract Additive manufacturing (AM) is an innovative technology that creates parts by adding small portions of materials layer by layer, which frees designers to create parts that were not possible to manufacture with subtractive manufacturing processes previously. This led to wide-spread popularity of 3D-printing technology. In this technology. fused deposition modeling (FDM) is the most affordable one in the market now. Therefore, it is vital to understand how the print orientation, which can be customized very easily, affects the mechanical properties of the prints to maximize the strength of the product. This paper aims to present the methodology and results of the experimental characterization of the acrylonitrile butadiene styrene (ABS) 3D-printed part. Tensile characterization of ABS was performed to analyze anisotropic nature of 3D-printed parts caused by its unique manufacturing process. Specimens were printed with six different configurations: four raster ([45/−45], [30/−60], [15/−75] and [0/90]) and three build orientations (0 or flat, 45, and 90 degrees with respect to the build plate, all printed in [45/−45] raster orientation). Dogbone tensile specimens were printed and pulled using the tensile test machine. The young’s modulus, yield strength, ultimate strength, strain at failure, breaking strength were found for each configuration. As the build orientation angle increased and the raster orientation goes from [45/−45] to [0/90], mechanical properties decreased steadily except the Young’s modulus. For build orientation, Young’s modulus decreased first then increased as angle increased, and for the raster orientation, there was no statistically significant difference as raster changed from [45/−45] to [0/90]. Overall, [45/−45] flat configuration is the strongest and the most stable configuration.

scholarly journals A 3D-Printed Ultra-Low Young’s Modulus β-Ti Alloy for Biomedical Applications

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2792 ◽  
Author(s):  
Massimo Pellizzari ◽  
Alireza Jam ◽  
Matilde Tschon ◽  
Milena Fini ◽  
Carlo Lora ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Biomedical Applications ◽  
Young's Modulus ◽  
Total Elongation ◽  
Potential Candidate ◽  
Β Phase ◽  
Grade 5 ◽  
Heat Treated ◽  
Columnar Grains ◽  
3D Printed

The metastable β-Ti21S alloy is evaluated as a potential candidate for biomedical parts. Near fully dense (99.75 ± 0.02%) samples are additively manufactured (that is, 3D-printed) by laser powder-bed fusion (L-PBF). In the as-built condition, the material consists of metastable β-phase only, with columnar grains oriented along the building direction. The material exhibits an extremely low Young’s modulus (52 ± 0.3 GPa), which was never reported for this type of alloy. The combination of good mechanical strength (σy0.2 = 709 ± 6 MPa, ultimate tensile strength (UTS) = 831 ± 3 MPa) and high total elongation during tensile test (21% ± 1.2%) in the as-built state, that is, without any heat treatment, is close to that of the wrought alloy and comparable to that of heat treated Ti grade 5. The good biocompatibility attested by cytotoxicity tests confirms its great suitability for biomedical applications.

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