scholarly journals Use of Particle Image Velocimetry (PIV) technique to measure strains in geogrids

2019 ◽  
Vol 92 ◽  
pp. 12007
Author(s):  
Chaminda Gallage ◽  
Chamara Jayalath
Keyword(s):  
Tensile Strength ◽  
Retaining Wall ◽  
Local Strain ◽  
Tensile Tests ◽  
Experimental Program ◽  
Strain Gauges ◽  
Data Logging ◽  
Piv Technique ◽  
Image Velocimetry ◽  
Secant Stiffness

Geosynthetics are widely used in Geotechnical Engineering to reinforce soil/gravel in pavements, retaining wall backfills, and embankments. It is important to measure strains in geogrids in the determination of their strength parameters such as tensile strength and secant stiffness, and in evaluating their performances in geogrid-reinforced structures. Strain gauges are commonly used in measuring strains in geogrids. However, it is important to verify the strains measured by strain gauges as these strains are affected by the data logging device, gauge factors, quality of bonding between grain gauge and geogrid, and temperature. Therefore, this study was conducted to verify the performance of strain gauges attached to Geogrids and also to investigate the possibility of using PIV technique and GeoPIV-RG software to measure the local strains developed in a geogrid specimen under tensile testing in the laboratory. In the experimental program of this study, six composite geogrid specimens were tested for tensile strength (wide-width tensile tests) while measuring/calculating its tensile strain by using strain gauges attached to the specimens, Geo-PIV-RG analysis and crosshead movements of Instron apparatus. Good agreement between the strains obtained from strain gauges and geoPIV-RG analysis was observed for all the tests conducted. These results suggest that the PIV technique along with geoPIV-RG program can effectively be used to measure the local strain of geogrids in the laboratory tests. It was also able to verify that properly installed strain gauges are able to measure strain in the geogrids which are used in the field applications.

scholarly journals Mechanical characterization of 3D printed concrete subjected to dynamic loading

2021 ◽  
Vol 250 ◽  
pp. 01009
Author(s):  
Rosanna Napolitano ◽  
Costantino Menna ◽  
Daniele Forni ◽  
Domenico Asprone ◽  
Ezio Cadoni
Keyword(s):  
Tensile Strength ◽  
High Strain Rate ◽  
Strain Rate ◽  
Waiting Time ◽  
High Strain ◽  
Waiting Times ◽  
Digital Fabrication ◽  
Tensile Tests ◽  
Experimental Program ◽  
3D Printed

In concrete structures realized by digital fabrication techniques, such as 3D concrete printing, under severe dynamic loadings (e.g. earthquakes and impact loads), the strength at the bond interfaces between layers is weak. Since these contact zones, also referred as cold joint, could potentially compromise the structural stability and also the durability of printed elements, their behaviour under high dynamic loads is fundamental to investigate. An experimental program on 3D printed concrete elements varying the waiting time, through medium and high strain-rate tensile tests is running, with a Hydro-Pneumatic Machine and a modified Hopkinson tensile bar respectively. The results of dynamic tensile tests at three different strain rates (10-5, 50 and 200 s-1) on 3D printed cementitious elements for waiting times of 0min, 10min and 30 min have been presented, in terms of Dynamic increase factors DIF versus strain rate, showing a behaviour highly strain-rate sensitive, recording an increase in tensile strength DIF up to 7.6 in the case of high strain-rate and waiting time of 30 min. The results exhibited a decrease in the dynamic interface tensile strength with the waiting time up to over 90% for a medium strain-rate and over 20% for a high strain-rate.

scholarly journals Influence of Hydrostatic Extrusion on the Mechanical Properties of the Model Al-Mg Alloys

2021 ◽  
Author(s):  
Aleksandra Towarek ◽  
Wojciech Jurczak ◽  
Joanna Zdunek ◽  
Mariusz Kulczyk ◽  
Jarosław Mizera
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Microstructural Analysis ◽  
Tensile Tests ◽  
Hydrostatic Extrusion ◽  
Microstructure Formation ◽  
Initial State ◽  
Degree Of Deformation ◽  
Al Mg Alloys

AbstractTwo model aluminium-magnesium alloys, containing 3 and 7.5 wt.% of Mg, were subjected to plastic deformation by means of hydrostatic extrusion (HE). Two degrees of deformation were imposed by two subsequent reductions of the diameter. Microstructural analysis and tensile tests of the materials in the initial state and after deformation were performed. For both materials, HE extrusion resulted in the deformation of the microstructure—formation of the un-equilibrium grain boundaries and partition of the grains. What is more, HE resulted in a significant increase of tensile strength and decrease of the elongation, mostly after the first degree of deformation.

scholarly journals Influence of Mechanical Vibration Moulding Process on the Tensile Properties of TiC Reinforced LM6 Alloy Composite Castings

2011 ◽  
Vol 66-68 ◽  
pp. 1207-1212 ◽  
Author(s):  
Mohd Sayuti ◽  
Shamsuddin Sulaiman ◽  
B.T. Hang Tuah Baharudin ◽  
M.K.A.M. Arifin ◽  
T.R. Vijayaram ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Titanium Carbide ◽  
Tensile Properties ◽  
Mechanical Vibration ◽  
Weight Fraction ◽  
Tensile Tests ◽  
Alloy Matrix ◽  
Remarkable Effect ◽  
Moulding Process ◽  
Particulate Reinforced

Vibrational moulding process has a remarkable effect on the properties of castings during solidification processing of metals, alloys, and composites. This research paper discusses on the investigation of mechanical vibration mould effects on the tensile properties of titanium carbide particulate reinforced LM6 aluminium alloy composites processed with the frequencies of 10.2 Hz, 12 Hz and 14 Hz. In this experimental work, titanium carbide particulate reinforced LM6 composites were fabricated by carbon dioxide sand moulding process. The quantities of titanium carbide particulate added as reinforcement in the LM6 alloy matrix were varied from 0.2% to 2% by weight fraction. Samples taken from the castings and tensile tests were conducted to determine the tensile strength and modulus of elasticity. The results showed that tensile strength of the composites increased with an increase in the frequency of vibration and increasing titanium carbide particulate reinforcement in the LM6 alloy matrix.

scholarly journals Mimicking the Mechanical Properties of Aortic Tissue with Pattern-Embedded 3D Printing for a Realistic Phantom

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5042
Author(s):  
Jaeyoung Kwon ◽  
Junhyeok Ock ◽  
Namkug Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
3D Printing ◽  
Mechanical Characteristics ◽  
Aortic Wall ◽  
Tensile Tests ◽  
Human Aorta ◽  
Aortic Tissue ◽  
Medical Field ◽  
Base Materials

3D printing technology has been extensively applied in the medical field, but the ability to replicate tissues that experience significant loads and undergo substantial deformation, such as the aorta, remains elusive. Therefore, this study proposed a method to imitate the mechanical characteristics of the aortic wall by 3D printing embedded patterns and combining two materials with different physical properties. First, we determined the mechanical properties of the selected base materials (Agilus and Dragonskin 30) and pattern materials (VeroCyan and TPU 95A) and performed tensile testing. Three patterns were designed and embedded in printed Agilus–VeroCyan and Dragonskin 30–TPU 95A specimens. Tensile tests were then performed on the printed specimens, and the stress-strain curves were evaluated. The samples with one of the two tested orthotropic patterns exceeded the tensile strength and strain properties of a human aorta. Specifically, a tensile strength of 2.15 ± 0.15 MPa and strain at breaking of 3.18 ± 0.05 mm/mm were measured in the study; the human aorta is considered to have tensile strength and strain at breaking of 2.0–3.0 MPa and 2.0–2.3 mm/mm, respectively. These findings indicate the potential for developing more representative aortic phantoms based on the approach in this study.

scholarly journals Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3943
Author(s):  
Hana Šebestová ◽  
Petr Horník ◽  
Šárka Mikmeková ◽  
Libor Mrňa ◽  
Pavel Doležal ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fusion Zone ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Laser Weld ◽  
Martensitic Microstructure ◽  
Laser Welds ◽  
Weld Properties ◽  
Weld Fusion Zone

The presence of Al-Si coating on 22MnB5 leads to the formation of large ferritic bands in the dominantly martensitic microstructure of butt laser welds. Rapid cooling of laser weld metal is responsible for insufficient diffusion of coating elements into the steel and incomplete homogenization of weld fusion zone. The Al-rich regions promote the formation of ferritic solid solution. Soft ferritic bands cause weld joint weakening. Laser welds reached only 64% of base metal's ultimate tensile strength, and they always fractured in the fusion zone during the tensile tests. We implemented hybrid laser-TIG welding technology to reduce weld cooling rate by the addition of heat of the arc. The effect of arc current on weld microstructure and mechanical properties was investigated. Thanks to the slower cooling, the large ferritic bands were eliminated. The hybrid welds reached greater ultimate tensile strength compared to laser welds. The location of the fracture moved from the fusion zone to a tempered heat-affected zone characterized by a drop in microhardness. The minimum of microhardness was independent of heat input in this region.

scholarly journals Microscale local strain gauges based on visible micro-disk lasers embedded in a flexible substrate

2018 ◽  
Vol 26 (13) ◽  
pp. 16797 ◽  
Author(s):  
Taojie Zhou ◽  
Jie Zhou ◽  
Yuzhou Cui ◽  
Xiu Liu ◽  
Jiagen Li ◽  
...  
Keyword(s):  
Flexible Substrate ◽  
Local Strain ◽  
Strain Gauges

Using Embossing to Create a Fiber Reinforced Honeycomb Composite

2005 ◽  
Vol 127 (2) ◽  
pp. 257-262 ◽  
Author(s):  
William Jordan
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Carbon Fibers ◽  
Flexural Modulus ◽  
Testing Machine ◽  
Charpy Impact ◽  
Tensile Tests ◽  
Hydraulic Testing ◽  
Charpy Impact Toughness ◽  
Bend Tests

This research project used hot embossing to create a strong and tough polymeric based composite structure. A honeycomb type structure was created by pressing small grooves into thin polycarbonate sheets. A trapezoidal die was used to create hexagonal shaped channels in the polymeric sheet. A number of these sheets were then bonded together to form a composite material. Carbon fibers were embedded into the channels in some of the laminates. The embossing process was carried out at an elevated temperature in an environmental chamber attached to an MTS servo hydraulic testing machine. The grooved structure had a 31% to 45% decrease in the apparent density compared to the ungrooved specimens. Bend tests, tensile tests, and Charpy impact tests were performed on laminates made from this material. The specific values of tensile strength, flexural modulus, and Charpy impact toughness were increased. A small percentage of fibers significantly increased both the stiffness and strength of the laminate.

Influence of Alkalinity and Ambient Temperature on Long-Term Properties of GFRP Reinforcement

2018 ◽  
Vol 760 ◽  
pp. 213-218
Author(s):  
František Girgle ◽  
Lenka Bodnárová ◽  
Ondřej Januš ◽  
Vojtěch Kostiha
Keyword(s):  
Tensile Strength ◽  
Ambient Temperature ◽  
Mechanical Characteristics ◽  
Current Problem ◽  
Concrete Structures ◽  
Experimental Program ◽  
Glass Fibres ◽  
Metallic Reinforcement ◽  
Gfrp Reinforcement

The article deals with the current problem of determining long-term reliability of non-metallic reinforcement in concrete structures. The alkaline environment of concrete with a pH higher than 12.0 affects the glass fibres degradative, whereas this degradation presents by reduction of their mechanical characteristics, resulting in a decrease in the tensile strength of the whole composite. The article summarizes the results of the ongoing experimental program so far, which aims to quantify this influence.

scholarly journals Effect of Cu Content on Performance of Sn-Zn-Cu Lead-Free Solder Alloys Designed by Cluster-Plus-Glue-Atom Model

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2335
Author(s):  
Jialong Qiu ◽  
Yanzhi Peng ◽  
Peng Gao ◽  
Caiju Li
Keyword(s):  
Tensile Strength ◽  
Solder Alloy ◽  
Tensile Tests ◽  
Melting Behavior ◽  
Second Phase ◽  
Solder Alloys ◽  
Cu Content ◽  
Diffusion Force ◽  
Fine Microstructure ◽  
Effect Of Copper

The mechanical properties of solder alloys are a performance that cannot be ignored in the field of electronic packaging. In the present study, novel Sn-Zn solder alloys were designed by the cluster-plus-glue-atom (CPGA) model. The effect of copper (Cu) addition on the microstructure, tensile properties, wettability, interfacial characterization and melting behavior of the Sn-Zn-Cu solder alloys were investigated. The Sn29Zn4.6Cu0.4 solder alloy exhibited a fine microstructure, but the excessive substitution of the Cu atoms in the CPGA model resulted in extremely coarse intermetallic compound (IMC). The tensile tests revealed that with the increase in Cu content, the tensile strength of the solder alloy first increased and then slightly decreased, while its elongation increased slightly first and then decreased slightly. The tensile strength of the Sn29Zn4.6Cu0.4 solder alloy reached 95.3 MPa, which was 57% higher than the plain Sn-Zn solder alloy, which is attributed to the fine microstructure and second phase strengthening. The spreadability property analysis indicated that the wettability of the Sn-Zn-Cu solder alloys firstly increased and then decreased with the increase in Cu content. The spreading area of the Sn29Zn0.6Cu0.4 solder alloy was increased by 27.8% compared to that of the plain Sn-Zn solder due to Cu consuming excessive free state Zn. With the increase in Cu content, the thickness of the IMC layer decreased owing to Cu diminishing the diffusion force of Zn element to the interface.

scholarly journals Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Solution Temperature ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Different Temperatures

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

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