scholarly journals The study of the bending property of the epoxy (Ep / MgO) and (Ep/SiO2) composites in natural conditions and after immersion in chemical solution

2019 ◽  
Vol 16 (39) ◽  
pp. 93-102
Author(s):  
Baraa Khalil Ibrahim
Keyword(s):  
Sulfuric Acid ◽  
Weight Ratio ◽  
Base Material ◽  
Load Level ◽  
Bending Test ◽  
Chemical Solution ◽  
Natural Conditions ◽  
Three Point Bending ◽  
Bending Property ◽  
Dioxide Powder

In this paper, a polymer-based composite material was prepared by hand Lay-up method consisting of epoxy resin as a base material reinforced by magnesium oxide powder once and silicon dioxide powder again and with different weight ratios (3, 6, 9 and 12) wt %. The three-point bending test was performed in normal conditions and after immersion in sulfuric acid. The results showed that the bending value decreased with the increase of the weighted ratio of the reinforcement material (MgO, SiO2). The Bending of samples reinforced by SiO2 was found to be less than the bending of samples reinforced by particles (MgO). For example, the bending of the SiO2 sample (0.32 mm) at the weighted ratio (3%) and for the MgO (0.18mm) sample at the weight ratio were the same weighted load (100 g). It was found that the bending values of all samples exceeded the value after immersion in sulfuric acid. For example, the percentage of weight (6%) at the load level (500 g) was changed from 1.16 mm in normal conditions to 1.48mm for the same weight ratio after immersion. In sulfuric acid diluted with 0.3N for 10 days at the same applied load.

scholarly journals Effect of sulfuric acid solution on thermal conductivity and impact strength of epoxy resin reinforced by silicon dioxide powder

2019 ◽  
Vol 17 (41) ◽  
pp. 82-90
Author(s):  
Baraa Khalil Ibrahim
Keyword(s):  
Thermal Conductivity ◽  
Sulfuric Acid ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Weight Ratio ◽  
Chemical Solution ◽  
Dioxide Powder ◽  
Before And After ◽  
Percentage Weight ◽  
The Impact

In this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared by hand Lay-up method, to measure the change in the thermal conductivity and Impact Strength of epoxy resin before and after immersion in H2SO4 Solution with a 0.3N for 10 days. The results before immersion decreases with the increase of the weight ratios of the reinforcement material (SiO2), It changed from (82.6×10-2 to 38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) % respectively, but after immersion time in the chemical solution where it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became (46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of the Impact strength decreased by increasing the percentage weight ratio, it changed from (1.48 to 0.87 kJ/m2) with change weight ratios from (3 to 12) % respectively, but found an increase in the value of Impact Strength after immersion in the chemical solution Where it was (1.28 kJ/m2) at the weight ratio of 6 % and became (1.82 kJ/m2) at the same weight ratio after immersion in sulfuric acid at normality of 0.3 for 10 days.

Investigation of Mechanical Properties of Nano Sized Clay/LDH Particle as Hybrid Nano Composite Material

2015 ◽  
Vol 766-767 ◽  
pp. 355-361
Author(s):  
S. Sivasaravanan ◽  
V.K. Bupesh Raja ◽  
S. Prabhu ◽  
S. Dineshkumar ◽  
Gokulaprasad
Keyword(s):  
Composite Material ◽  
Testing Machine ◽  
Weight Ratio ◽  
High Strength ◽  
Sem Analysis ◽  
Bending Test ◽  
Flexural Property ◽  
Weight Percentage ◽  
Three Point Bending ◽  
Sonication Technique

Usage of Hybrid nanocomposite materials provides a greater opportunity to replace the conventional materials due to their properties such as light weight and high strength to based on weight ratio. In this synergitic study, nanosized clay particle and layered double hydroxide particles are used. nanoclay and LDH particles were mixed on the bases of weight percentage (1wt% to 5wt%) by ultra sonication technique. The composite material was fabricated by one of the most common method known as hand lay-up technique. The composite materials was prepared in the form of plate with 4mm of thickness.The characterization of tensile and flexural property of the nanoclay, LDH and combination of both was analysis by tensile test using universal testing machine and three point bending test respectively. The tensile and three point bending test specimens were cut to size as per ASTM standard.The morphology of composite was studied using SEM analysis.

Effect of the shot peening process on the fatigue strength of SAE 5160 steel

2018 ◽  
Vol 233 (12) ◽  
pp. 4328-4335 ◽  
Author(s):  
Héctor E Jaramillo S ◽  
Nelly Alba de Sánchez ◽  
Julian A Avila D
Keyword(s):  
Fatigue Strength ◽  
Shot Peening ◽  
Base Material ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Correlation Factor ◽  
Bending Test ◽  
Three Point Bending ◽  
Before And After ◽  
Almen Intensity

The fatigue behaviour of SAE 5160 steel was evaluated before and after applying a shot peening process by using different Almen intensities and surface coverings (uncovered, partial coverage and total coverage). In the high-cycle fatigue tests, maximum stresses of 0.8 Sut, 0.7 Sut and 0.6 Sut were applied in the three-point bending test on an Instron 8872 servo-hydraulic machine at a frequency of 10 Hz and a constant stress ratio of Smin/ Smax = 0.2 for all tests. The fatigue tests were performed based on the ASTM E8, the specimens were classified into six groups for each stress evaluated, and each group consisted of three standardised specimens (ASTM E466). Also, yield strength, ultimate strength, hardness and microhardness were obtained. The Wilcoxon’s non-parametric test was used to statistically compare all the mechanical properties obtained from the base material with those obtained after the application of the shot peening, for the different surface coverings and Almen intensities. The results showed that the shot peening process significantly increases the fatigue strength of the material, with a 94% increase in fatigue strength of the fully coated specimens. However, no significant increase in fatigue strength was found due to a change in the Almen intensity value. A high correlation factor was found between the increase in the ultimate resistance and the increase in Almen intensity; however, for the yield stress the correlation was medium and inverse. For hardness and microhardness, the correlation factor was very low. Finally, the microhardness values revealed a 3% increase in Vickers microhardness of the shot peening specimens compared to the untreated specimens.

scholarly journals Influence of Different Reline Materials and Processing Methods on Flexural Strength of Denture Base Material

2021 ◽  
Vol 25 (2) ◽  
pp. 108-113
Author(s):  
Ozlem Gurbuz Oflezer ◽  
Hakan Bahadır ◽  
Senem Ünver ◽  
Ceyhan Oflezer
Keyword(s):  
Flexural Strength ◽  
Base Material ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Processing Methods ◽  
Denture Base ◽  
Three Point Bending ◽  
Heat Cure ◽  
And Control

Summary Background/Aim: Relining is defined as the procedure used to resurface the tissue side of a denture with new base material, thus producing an accurate adaptation is provided at the denture foundation area. During mastication, relined dentures have to withstand masticatory forces to prevent fracture. The aim of this study was to evaluate the flexural strength of acrylic resin denture base relined with different methods and materials. Material and Methods: Fourteen experimental groups and one control group were determined to consider different reline materials and processing methods. Acrylic resin specimens were prepared with the dimensions of 65× 10× 1.5 mm and reline materials (1.5 mm thickness) were placed on acrylic resins. Reline material was not used in control group specimens. Flexural strength values of relined and control specimens were measured with three-point bending test at a speed of 5 mm/min. Data were analyzed with using one way Anova and Student t tests. Results: The highest flexural strength values were shown in control group (86.51±1.08 MPa). There were significant differences among relined specimens (p< 0.05). For the relined specimens, the highest flexural strength values were found in the relined specimens with denture base material (77.90±1.93 MPa), and the lowest values were found in relined with autopolymerize acrylic material (59.81±1.50 MPa). Conclusions: Relining of the heat cure denture base material significantly decreases the flexural strength for all processing methods and materials.

Simulative analysis of the bending property of woven fabric by the comprehensive handle evaluation system for fabrics and yarns

2016 ◽  
Vol 87 (16) ◽  
pp. 1977-1990 ◽  
Author(s):  
Fengxin Sun ◽  
Chaoyu Chen ◽  
Sai Liu ◽  
Huanhuan Jin ◽  
Linge He ◽  
...  
Keyword(s):  
Evaluation System ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Bending Test ◽  
Element Analysis ◽  
Textile Materials ◽  
Three Point Bending ◽  
Bending Property ◽  
Bending Process ◽  
Force Displacement

The comprehensive handle evaluation system for fabrics and yarns can be used to measure the bending property of fabrics and yarns based on three-point bending, in principle. In order to gain a better understanding of the bending mechanism of woven fabrics under three-point bending and to better interpret the influencing factors in the bending process, weaving-structure models of woven fabrics were built using finite element analysis based on ABAQUS software. Simulated bending force–displacement curves were compared with experimental curves based on the bending characteristic parameters extracted from the curves, and stress distribution on the fabric and the pressing pin were visually displayed during the bending process. The results show that the simulated curves have good agreement with the experimental curves. The effects of the property parameters of materials, including the Poisson’s ratio, friction coefficient and modulus of yarns and the structure phase and thread arrangement density of fabrics, as well as apparatus parameters, including diameters, the interval of the supporting pins and the distance of the jaws, on bending test were investigated. It is expected that the three-point bending method will help better characterize the bending property of textile materials.

scholarly journals Pretensioned BFRP reinforced concrete beams: Flexural behaviour and estimation of initial prestress losses

2019 ◽  
Vol 289 ◽  
pp. 09001
Author(s):  
Ana Pavlović ◽  
Ted Donchev ◽  
Diana Petkova ◽  
Mukesh Limbachiya ◽  
Refad Almuhaisen
Keyword(s):  
Concrete Beams ◽  
Weight Ratio ◽  
Load Level ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Flexural Behaviour ◽  
Basalt Fibre ◽  
Cross Sectional ◽  
Prestress Losses ◽  
Initial Application

Fibre Reinforced Polymers (FRP) are becoming a popular reinforcement option for RC elements mainly due to good strength to weight ratio and resistance to corrosion. The main limitation for their wider application is their relatively low Young’s modulus, which results in unfavourable serviceability performance, in terms of early development of deflections and cracks. Among others, prestressing has been suggested as one of the possible approaches to addressing this issue, with encouraging results from research conducted so far. This experimental study aimed to explore prestress losses of basalt fibre reinforced polymer (BFRP) reinforced pretensioned concrete beams. Five beams were produced, three of them internally reinforced with 6mm diameter BFRP bars, pretensioned to 20%, 30% and 40% of the ultimate load level of prestress. Additionally, two beams, acting as control samples, were reinforced with unprestressed BFRP and steel bars of same cross-sectional area, respectively. The dimensions of all samples were 125x200x1900 mm. Prestress losses were monitored with the aid of strain gauges attached to the reinforcing bars, as well as load cells. The strain readings were continuously taken during the pretensioning process, from initial application of the prestressing force, during casting and curing of concrete, until releasing of the beams from prestressing devices after curing. Ultimately, all samples were subjected to a quasi-static, load-controlled, four-point bending test until destruction. The results provide the information about the flexural behaviour of pretensioned BFRP reinforced beams, along with insight into some of the initial prestress losses of these elements.

scholarly journals Additive Manufacturing-Based In Situ Consolidation of Continuous Carbon Fibre-Reinforced Polycarbonate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Carbon Fibre ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Material Structure ◽  
Three Point Bending ◽  
Continuous Fibre ◽  
Local Material

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.

Effect of Concrete Mixture Composition on Acoustic Emission and Fracture Parameters Obtained from Three-Point Bending Test

2015 ◽  
Vol 1100 ◽  
pp. 152-155
Author(s):  
Libor Topolář ◽  
Hana Šimonová ◽  
Petr Misák
Keyword(s):  
Acoustic Emission ◽  
Bending Test ◽  
Mixture Composition ◽  
Three Point Bending ◽  
Concrete Mixtures ◽  
Fracture Parameters ◽  
Fracture Tests ◽  
Stress Behaviour ◽  
Bending Fracture ◽  
Fracture Processes

This paper reports the analysis of acoustic emission signals captured during three-point bending fracture tests of concrete specimens with different mixture composition. Acoustic emission is an experimental tool well suited for monitoring fracture processes in material. The typical acoustic emission patterns were identified in the acoustic emission records for three different concrete mixtures to further describe the under-the-stress behaviour and failure development. An understanding of microstructure–performance relationships is the key to true understanding of material behaviour. The acoustic emission results are accompanied by fracture parameters determined via evaluation of load versus deflection diagrams recorded during three-point bending fracture tests.

scholarly journals Experimental and Numerical simulation of a Three Point Bending Test of a Stainless Steel Beam

2021 ◽  
Vol 55 ◽  
pp. 1114-1121
Author(s):  
Daniel Jindra ◽  
Zdeněk Kala ◽  
Jiří Kala ◽  
Stanislav Seitl
Keyword(s):  
Numerical Simulation ◽  
Stainless Steel ◽  
Bending Test ◽  
Steel Beam ◽  
Three Point Bending
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