Variation Of Tensile Strength Research Articles

Effects of Orientation and Temperature on the Tensile Strength of Pristine and Defective Bi-Layer Graphene Sheet – A Molecular Dynamics Study

Molecular dynamics simulations with adaptive intermolecular reactive empirical bond order (AIREBO) potential were carried out to study the effect of temperature and orientation on the tensile strength of pristine and defective bilayer graphene (BLG) sheet. Results obtained reveal that the fall in tensile strength of pristine AA stacked BLG due to the presence of vacancy is significant at room temperature (300 K) but decreases at higher temperature (1073 K). Interestingly, this phenomenon reverses in case of AB stacked BLG, wherein the percentage fall in strength at higher temperature due to defect is more than that at room temperature. In order to understand these discrepancies in the results obtained, three case studies were conducted, and the results obtained suggested that when defects are present in armchair direction, this phenomenon occurs. The study also reveals that in case of AB stacked BLG, zigzag direction is more defect tolerant at room and high temperatures. Interestingly, variation of tensile strength due to the orientation is in good agreement with projections from potential energy concepts and theoretical calculations. We envisage that the study will provide useful information to the device engineers for the optimisation of the mechanical properties and convenient structural adaptation of bilayer graphene while working at wide range of temperatures.

Weibull Strength Analysis of Pineapple Leaf Fiber

Pineapple leave fiber (PALF) can be considered as one of the green materials to the industries, which is the potential to replace the non-renewable synthetic fiber. However, the high disparity in the mechanical properties of PALF becomes an issue in structural composite design. Hence, improved Weibull distribution is utilised to quantify the tensile strength variation of PALF in various gauge lengths. The single fiber tensile test was performed after the fiber surface treatment and fiber diameter scanning. The predicted PALF strength by applying the improved Weibull distribution incorporating with conical frustum model is well compromised with experimental data compared to the traditional Weibull model.

Mechanical behaviors of graphene/copper matrix composite foils fabricated by pulse electrodeposition

The Graphene/copper matrix (Gr/Cu) composite foils were successfully fabricated by pulse electrodeposition from copper sulfate solution containing graphene nanoplates ranging from 0.04 to 1.6g/L. The morphology, microstructure, tensile properties and nanoindentation hardness of Gr/Cu composite foils were characterized. The results indicated that the few-layer graphene nanoplates were distributed in nanotwined Cu matrix, Gr/Cu composite foils existed in the form of graphene nanoplates wrapped by Cu grains. With the increase of graphene concentration in electrolyte, the tensile strength of Gr/Cu composite foil decreased from 367 to 236 MPa, then increased up to 274 MPa. Similarly, the hardness decreased from 2.02 to 1.44 GPa, and then increased up to 1.71 GPa. Then, the crystalline size (d) calculated based on the XRD patterns changed from 520 to 890 nm and then decreased to 710 nm. The variation of tensile strength and hardness was mainly attributed to the change of the crystalline size. Besides, graphene defects of Gr/Cu composite foils were taken into account to explain the change of tensile strength and hardness. The models for tensile strength, hardness and graphene concentration were proposed to evaluate the tensile strength and hardness of Gr/Cu composite foils.

Microstructure Evolution and Mechanical Properties of a Wire-Arc Additive Manufactured Austenitic Stainless Steel: Effect of Processing Parameter.

Two single track multi-layer walls with linear energy inputs (LEIs) of 219 and 590 J/mm were deposited by cold metal transfer-based wire arc additive manufacturing system. Combined with the X-ray diffraction technique, scanning electron microscope and uniaxial tensile tests, the influences of LEI and cooling rate (CR) on the microstructure evolution, mechanical properties and fracture mechanisms of the studied steel are analyzed. It is observed that the microstructures of the studied steel are mainly composed of δ-ferrite and austenite dendrites. σ phase is formed on the δferrite–austenite interface under low CR. Meanwhile, the primary dendrites’ spacing decreases with the decrease in LEI or the increase in CR, and the maximal primary dendrites’ spacing is 32 μm. The values of elongation to fracture roughly decline with the decrease in LEI or the increase in CR, but the variations of ultimate tensile strength and yield stress show an opposite trend. In addition, the mesoscopic damages in the studied steel under low LEI are mainly caused by the coalescence of pores. While under high LEI, the cracks are induced by the dislocations piling up around δ-ferrite.

Mangifera Indica mid-rib fibers as reinforcements for CNSL-epoxy composites

This research work explores the potential of Mangifera indica leaf mid-rib fibers as a reinforcement for polymer composites. The fibers were subjected to sodium bicarbonate treatment for 6 h, 12 h, 18 h, and 24 h duration and the effect of chemical treatment on the tensile strength of the fibers was evaluated. Maximum tensile strength of 104 MPa was obtained for 18 h treated fibers. Scanning electron microscopy of the fiber surface revealed surface impurities, layers of dead cells and degradation of fibrils, as some of the important features for variation in tensile strength. Fourier transform infrared spectra of all varieties of fibers supported function group modifications with chemical treatment. X-ray diffraction analysis of the fiber confirmed improvement in the crystallinity index of the fibers till duration of 18 h. Composites with untreated and 18 h treated fibers were considered for fabrication along with Cashew Nut Shell Liquid (CNSL)/epoxy matrix. Techniques such as hand layup and compression moulding were adopted for composite fabrication and mechanical properties of the cured composites were determined. Maximum values of tensile, flexural and impact strength obtained were 48 MPa, 70 MPa and 38 kJ/m2 respectively. Failure modes such as fiber pull-out, fiber shearing, fiber debonding and matrix shearing were observed through scanning electron micrographs of the Mangifera indica composites.

Combined effect of waste glass powder and recycled steel fibers on mechanical behavior of concrete

Several attempts upon inclusion of industrial waste materials such as fly ash, silica fume, GGBS, metakaolin and copper slag in concrete have already been experimented that exerted a significant impact on concrete with enhanced mechanical and improved durability properties. There were numerous authentic researches that reported the significance of steel fibers in strengthening the flexural property of concrete. The paper investigates the combined effect of waste glass powder (WGP) that has been utilized as a substitution for fine aggregate in varying percentages of 0%, 3%, 6%, 9%, 12% and 15% and further reinforcing it with recycled steel fibers (RSF), drawn from waste tires by volume of concrete. WGP was used as 0%, 3%, 6%, 9%, 12%, 15% by mass replacement of fine aggregate with four different volume fractions of recycled steel fiber (i.e., 0, 0.5, 1 and 1.5%), respectively. All proportions of concrete mixes were investigated to study the variations in compressive, flexural and split tensile strength with varied replacements levels of WGP along with various fractions of RSF for 7 and 28 days curing. A mix of 9% WGP exhibited the maximum compressive, flexural and split tensile strength. It was found that mechanical properties of concrete rose up to 9% replacement level of WGP and later declined. Also it was confirmed that increase in the amount of RSF further boosted the compressive and flexural behavior of concrete. Overall, an optimum concrete mix with 9% replacement of WGP, reinforced with 1% inclusion of RSF, reported the best performance compared to other mixes.

Nanofibers of cellulose acetate containing ZnO nanoparticles/graphene oxide for wound healing applications

A combination of nanostructured zinc oxide (ZnO) or graphene oxide or both of them with cellulose acetate (CA) enhances a new functionality of nanofibers aiming to improve bio-composite materials for wound healing application. The obtained nanofibers have been investigated using XRD, FTIR, and FESEM. It was observed that the maximum height of the roughness increased from 253 to 651.9 nm for both GO and ZnO/GO in the powdered phase, while it plunged from 613 to 482 nm and developed to 801 nm for ZnO@CA, GO@CA, and ZnO/GO@CA, receptively. Further, the mechanical properties of the obtained scaffolds have been tested and displayed a tremendous variation of tensile strength from 5.44 ± 0.81 to 12.87 ± 0.93 and 8.82 ± 1.2 MPa, while the toughness increased from 23.29 ± 1.4 to 68.95 ± 4.5 and 57.75 ± 3.6 MJ/m3 for ZnO@CA, GO@CA and ZnO/GO@CA, receptively. Moreover, the cell viability was investigated and showed a progression of 97.38 ± 3.9% for ZnO/GO@CA. Furthermore, the adhesion of human fibroblasts cell line towards the obtained nanofibrous scaffolds were examined and displayed that cells were proliferated and spread considerably through the scaffolds, whereas their filopodia have followed the morphology of the fibers.

Microstructure and Tensile Properties of Sn-Ag-Cu-In-Sb Solder

Microstructures and tensile properties at 233 K, 300 K and 398 K of Sn-3.0 mass%Ag-0.5 mass%Cu (SAC305) and Sn-Ag-Cu-In-Sb solder were investigated by using miniature size specimens with 0.5 mm diameter, which can reproduce the microstructure of the real solder joint. In this study, three kinds of Sn-Ag-Cu-In-Sb solder (SAC305-6.0 mass%In-1.0, 2.0 and 3.0 mass%Sb) were used. The microstructure of SAC305 consisted of a single crystal grain. On the other hand, the microstructures of Sn-Ag-Cu-In-Sb solder consisted of polycrystalline. The number of crystal grains per the cross section of SAC305-6.0In-1.0Sb was stably several tens or more. The tensile strength of Sn-Ag-Cu-In-Sb was improved approximately 2 times that of SAC305. Also, the variation in tensile strength of SAC305 at 233 K was large due to anisotropy of the crystal grain. In contrast, the variation in tensile strength of Sn-Ag-Cu-In-Sb at 233 K was lower than that of SAC305. In particular, that of SAC305-6.0In-1.0Sb was reduced to approximately a sixth of that of SAC305. It seems that the effect of anisotropy of the crystal grain is decreased by polycrystallization in SAC305-6.0In-1.0Sb.

Study of the influence of cotton fiber indicators on yarn quality

In order to determine the relationship between the fiber properties of the yarn quality in the article, experiments were conducted using a passive method of mathematical planning and a regression equation was obtained for each optimal parameter. Based on the experiments, it was found that a decrease in fiber micronaire, an increase in tensile strength, fiber length and uniformity, leads to an increase in the specific tensile strength of yarn, a decrease in the coefficient of variation in tensile strength and the number of breaks in the yarn.

Variation in tensile strength and failure mechanisms of carbon fiber reinforced plastics in presence of single, double and four holes along the loading direction

In today’s world, composites have got a diverse application in various fields such as automobiles, civil, aerospace because of its high strength to weight ratio as well as high resilience. Holes are introduced in composites to serve many purposes such as electrical wire installation, joining of various parts by using mechanical bolts etc. So, it is necessary to acknowledge the behavioural changes in the composite material due to existence of holes to design any component in an efficient manner. Effect of holes in isotropic material can be predicted easily as compared to anisotropic material. In this paper, an experimental study has been conducted on CFRP laminate in the company of holes introduced in top and bottom array to recognize the variation in the composite laminates tensile properties. From the results, it is concluded that the specimen with a single hole has lesser tensile load carrying capacity compared to specimen with multiple holes.

Variation of tensile strength and elastic limit due to tempering at low temperature on quenched medium carbon steel

Variation of tensile strength and elastic limit due to tempering at low temperature on quenched medium carbon steel

Focused Ion Beam-Prepared Transmission Electron Microscopy Examination of Atmospheric Chemical Vapor-Infiltrated Silicon Carbide Morphology.

Silicon carbide (SiC)-based ceramic matrix composites (CMCs) are utilized for their refractory properties in the aerospace industry. The composition and structure of these materials are crucial to maintaining the strength, toughness, oxidation, and creep resistances that are desired of silicon carbide. This work analyzes the chemical composition of the matrix in batches of SiC/SiC (silicon carbide fiber-reinforced silicon carbide matrix) minicomposites that are processed by chemical vapor infiltration of the BN interphase and SiC matrix on single Hi-Nicalon Type S fiber tows using a range of processing parameters. The analysis was performed here to investigate the potential causes of variation in matrix tensile strength in the various batches of minicomposites. Six different morphologies present in the silicon carbide matrix were observed: smooth, nodular, rough nodular, bumpy, nucleated, and plate-like. It was found that high-matrix tensile strength minicomposite batches contained solely the smooth morphology, while low-matrix tensile strength minicomposite batches contained a variety of other morphologies. FIB/TEM was used to study the atomic and crystal character of each individual morphology. Smooth SiC is oriented by the (111) planes and is primarily SiC, while the other morphologies are randomly oriented and contain significant oxygen. These results match the tensile strength tests, which pointed to smooth SiC as the strongest matrix material.

Influence of stirrer blade design on stir casting of Al Mg Cu/12% SiC composite

Aluminium metal matrix composites are generally produced employing stir casting technique. The effect of stirrer blade on stir casting of aluminium composite with 12 wt% SiC, 4 wt% magnesium and 2 wt% copper was observed. The composites were prepared with 6061 base metal using three different design of stirrer blade which created different vortex fluid flow while stirring. Due to high density of SiC particles, it tries to settle in lower part of the molten metal matrix. Hence change in vortex technique by stirrer design modification can have influence on the mechanical and microstructure behaviour of the composites. The aluminium SiC composite are evaluated by mechanical properties and microstructure analysis based on stirrer blade design used while stir casting. The change in blade stirrer shows variation in testing tensile strength and hardness. The optical microstructure and SEM images were observed to analyze the cast structure and reinforcement distribution in the composites. The SiC particles were appeared to distribute along the grain boundaries of the composite and also cast defects were observed. Composite prepared with alternate peddle blade produced best mechanical properties.

재료 압출 방식 3D 프린팅 시편에서 적층 경로에 따른 인장강도의 변화

재료 압출 방식 3D 프린팅 시편에서 적층 경로에 따른 인장강도의 변화

Using infrared spectrum analyses to predict tensile strength of fibres in a group of closely related plant species: case of Mascarenes Pandanus spp.

Replacing synthetic fibres with natural ones is key for clean and sustainable manufacturing. Natural fibres require characterization to investigate their usefulness. However, current testing methodologies require a large sample size due to the strong variation of tensile strength (TS) among the fibre of the same plant species. The development of a simpler test method to predict fibre TS would help in the selection of the most appropriate plant species with desirable TS values while performing fewer tests; thus saving on time and cost. FT-IR results that determine fibre crystallinity through specific IR absorbance peak ratios may serve to predict the fibre TS. In this study, we tested the relationship between fibre TS and cellulose crystallinity for seven different species of Pandanus spp. Thus, empirical mathematical relationships between the fibre TS value and indices obtained by three specific IR absorbance peaks ratios, namely the total crystallinity index, lateral order index, and hydrogen bond index have been established with a good correlation coefficient (96, 98, and 95%, respectively).

Effects of temperature and fiber orientation on the tensile behavior of short carbon fiber reinforced PEEK composites

AbstractShort carbon fiber reinforced poly‐ether‐ether‐ketone (SCF/PEEK) composites have attracted great attention in automobile and aerospace industries for their excellent thermal and mechanical properties. To investigate the anisotropy and temperature effects on mechanical properties of SCF/PEEK composites, tensile tests were conducted in various mold flow directions at 23, 80, 140, and 200°C. Results show that the tensile behavior of SCF/PEEK is highly influenced by temperature and fiber orientation. Both tensile strength and elastic modulus decrease with the increasing of temperature, and fracture strain increases with the increasing of temperature. Scanning electron microscopy was conducted to investigate the effects of anisotropy and temperature on fracture mechanism by scanning the tensile fracture surfaces. A shell‐core‐shell structure across the sample thickness was observed. Fibers are mainly aligned in mold flow direction in shell layers and perpendicular to the mold flow direction in core layers. The anisotropy of SCF/PEEK composites is fiber orientation dominated, and the temperature‐dependence of SCF/PEEK is matrix‐dominated. The variations of elastic modulus and tensile strength with temperature were mathematically represented. Constitutive model was established to predict the stress‐strain curves over a wide range of temperatures. Overall, the constitutive model could predict the temperature dependent stress‐strain relationships well.

FABRICATION OF AN ABUSE DETERRENT AND MICROEMULSION-BASED SUBLINGUAL FILM OF BUPRENORPHINE HYDROCHLORIDE FOR BREAKTHROUGH PAIN MANAGEMENT

Objective: The present research work aims to develop an abuse deterrent rapidly dissolving buprenorphine microemulsion loaded sublingual film for the treatment of breakthrough pain.
 Methods: The Buprenorphine microemulsion loaded sublingual films were prepared using Capmul MCM C8 (oil), tween 20 (surfactant) and propylene glycol (co-surfactant) with different grades of film-forming polymer (HPMC) using film casting machine. The films were evaluated for in vitro disintegration and dissolution study, tensile strength, folding endurance, content uniformity, surface pH, thickness and weight variation, % loading of buprenorphine microemulsion in sublingual film, scanning electron microscope, ex vivo permeation study, droplet size and polydispersity index, Zeta potential, % moisture content, stability and abuse deterrent potential were evaluated.
 Results: The optimized film formulation showed desired mechanical properties with minimum disintegration time of 21s and exhibited 34.45 % loading of Buprenorphine microemulsion. Permeation studies through goat sublingual mucosa, indicated 87% Buprenorphine release, through Buprenorphine microemulsion loaded sublingual film, whereas only 30% Buprenorphine release when it was directly added to film without microemulsion strategy.
 Conclusion: The present study concludes that abuse deterrent and fast acting buprenorphine microemulsion-incorporated sublingual film of buprenorphine HCL and naloxone HCL is a promising alternative to mostly marketed buprenorphine injectable delivery systems and a non-invasive route of administration for breakthrough pain management.

Finite Element Study on the Shear Capacity of Traditional Joints between Walls Made of AAC Masonry Units.

This paper presents the development of a numerical model aimed at the simulation of nonlinear behaviour of traditional joints between walls made of autoclaved aerated concrete (AAC) masonry units. Nonlinear behaviour and cracking of AAC and mortar were simulated using the concrete damaged plasticity (CDP) model available in the ABAQUS finite element software. The paper also presents and discusses the results of an experimental campaign involving testing six T-shaped, monosymmetric samples with traditional joints between walls loaded in shear. The results were used to validate the numerical model. The validation confirmed that the model is capable of producing accurate results and predicting the structural behaviour with a reasonably good accuracy in elastic and post-elastic stages. Furthermore, a sensitivity study was conducted, in which the variation of elastic modulus, Poisson’s ratio, tensile strength, compression strength and fracture energy of AAC was investigated. Results showed that the variation of elastic modulus, tensile strength and fracture energy is most critical to the structural behaviour of the model, while variation of the remaining parameters has a negligible effect on the results.

Simulating fracture initiation from inclined wellbore in layered reservoir using analytical model

ABSTRACT For the layered reservoirs such as shale, the anisotropic mechanical properties exhibit variations in elastic modulus and tensile strength, both of which are factors influencing fracture initiation pressure (FIP) from the wellbore. The previous works are mainly concentrated on analyzing the influence of elastic modulus anisotropy but the anisotropic tensile strength is usually ignored. In this study, we extended the previous work by considering the effect of both elastic modulus and tensile strength anisotropy to predict FIP in layered reservoir. The analytical solution of stress concentration around wellbore in anisotropic reservoir is adopted, and a layered tensile strength formula applied to 3-D stress conditions is developed. We verified the model with numerical simulation and experimental data. Results show that both elastic modulus anisotropy and tensile strength anisotropy are important factors affecting FIP, and the influence of anisotropic modulus is greater than anisotropic tensile strength. FIP reduces monotonously with the degree of Young’s modulus anisotropy and tensile strength anisotropy increasing. Besides, when the Young’s modulus anisotropy ratio (the ratio between the Young’s modulus in the layered planes and normal to the layered planes) is larger than 3, there is a drastic reduction of FIP by 100% at high wellbore inclination (≥75°). Furthermore, the effect layered planes occurrence is tremendous when the wellbore is close to parallel to the layered planes, and the reduction of FIP can be as much as 17%. Moreover, the influence of anisotropy on FIP is significant under normal fault and strike slip, and the maximum FIP reduction is 19%. This work is meaningful for developing unconventional reservoir.

Characterization of a Novel Polyalthia Longifolia Mid-rib Fibers as a Potential Reinforcement for Polymer Composites

This research work makes use of a novel polyalthia longifolia leaf mid-rib fibers as a potential reinforcement for polymer composites. The fibers were subjected to sodium hydroxide treatments for different duration, and its effect on the tensile strength of the polyalthia fibers was examined. 6 h treatment was found to be optimum with a maximum tensile strength of 134 MPa. Scanning electron microscopy of the fiber surface revealed surface impurities, waxy granules and breakage of fibrils as some of the prominent features for variation in tensile strength. Fourier transform infrared spectra of all varieties of fibers supported function group modifications. Polyester-based composites were fabricated with 6 h treated fibers, and their mechanical properties were determined. Maximum values of tensile, flexural and impact strength obtained were 43MPa, 35MPa and 12 kJ/m2 respectively. Fiber breakage, fiber pull-out and de-bonding were some of the fracture mechanisms observed through scanning electron micrographs of the polyalthia longifolia composites.