Reinforcement Size Research Articles

A finite element study of interphase properties and reinforcement size effect on the electro-elastic properties of PMN-0.3PT/PDMS nanocomposite

A finite element study of interphase properties and reinforcement size effect on the electro-elastic properties of PMN-0.3PT/PDMS nanocomposite

Effect of NiCoFeAlTi high entropy intermetallic reinforcement particle size on the microstructure and mechanical properties of CoCrFeMnNi high-entropy alloy composites fabricated by selective laser melting

The particle size of the reinforcement affects the microstructure and mechanical properties of the composites fabricated by selective laser melting. The powder bed characteristics were greatly influenced by the size of the powder particles. In this research, CoCrFeMnNi high entropy alloys (HEAs) were reinforced with NiCoFeAlTi high entropy intermetallics (HEI) where two different reinforcement sizes were utilized. The microstructure and mechanical properties of CoCrFeMnNi HEA matrix with NiCoFeAlTi HEI reinforcement with varying particle sizes were investigated systematically. The composites reinforced with fine particle size exhibit stress-induced intergranular cracking, element segregation, and poor mechanical properties. On the other hand, composites reinforced with coarser particle size display crack and pore-free microstructure with uniform compositional distribution and relatively outstanding mechanical properties. This work contributes to a further understanding of the influence of reinforcement particle size on the crack-sensitive composites fabricated by selective laser melting.

Experimental investigation on feasibility of industrial waste to resource conversion for cupola slag

Cupola slag, an industrial waste produced as by-product in producing cast iron. Demand for cast iron is high consequently, there is significant slag formation. These waste slags ends in landfill and pollutes the environment. Pollution due to cupola slag can be reduced by conversion of waste to resource. In this work waste slag has been analysed physically and chemically to understand its conversion potential. An experimental attempt has been made to convert cupola slag to reinforcement in aluminium metal matrix composite (AMC) for fabrication of economic metal matrix composites by stir casting route. Experimental studies are designed to observe the feasibility of waste to resource conversion along with effect of size of reinforcement on the mechanical, physical and microstructural properties of AMCs. The results indicate feasible conversion from waste to resource. Microstructural studies baked by energy dispersive spectroscopy (EDS) and elemental mapping indicates uniform and successful inclusion of reinforcement in the matrix of composites. The grains have been refined by the addition of slag particle in the Al alloy matrix. Microhardness has been increased in composites when compared to base alloy. Coarse (100 μm) reinforcement particle composites are observed to have better mechanical properties than that of fine (40 μm) reinforcement particles.

Finite Element-Based Performance Analysis of Encased Composite Columns under Monotonic Axial Compression Load

This paper presents the results of an investigation into the performance of fully encased composite columns under monotonic axial load using finite element simulation. The damage characteristics and the performance investigation of the specimen were mainly focused on the influence of the compressive strength of concrete and the size of reinforcement. The concrete material was modeled using concrete damage plasticity (CDP), which incorporates the hardening and softening behaviors, and the steel was modeled using metal plasticity. The results obtained from the current study were validated by using previously conducted experimental work and manual calculation based on Eurocode 4. According to the FEA result, damage to the concrete matrix was significantly minimized with the increase in the strength of the concrete. By keeping other parameters constant, an increase in longitudinal reinforcement diameter minimizes the equivalent plastic strain both in structural steel and reinforcement bars. Furthermore, the results showed that the numerical simulation fairly validated the analytical solution.

Strengthening and toughening of Cu matrix composites reinforced by metallic glass particles with variable size

Metallic glass particle reinforced CuCrZr composites with excellent mechanical and electrical properties are manufactured by ball milling and spark plasma sintering. The effect of reinforcement size on the microstructure and properties of composites is investigated. As the size of metallic glass particles decreases, the strength and toughness of the composites are jointly increased. Quantitative results of the strengthening mechanism show that the strength is mainly provided by grain boundaries and metallic glass particles, with the fine and dispersed metallic glass reinforcements contributing more to the strength. Furthermore, crack extension behavior under uniaxial compression is observed for composite sections. The results indicate that cracks sprout and expand along the interface, and the interface bonding modified by the ball milling (BM) process can effectively inhibit the crack merging process. In particular, the crack extension rate corresponds to the plasticity of the particle-reinforced composite as determined by the interfacial properties, particle size and distribution of the reinforcement.

Strengthening behaviour of forged in-situ developed magnesium composites

ABSTRACT Mg alloys/composites can fulfil evolving needs of the automotive industry. Mg-based in-situ developed metal matrix nano-composites (MMnCs) are not researched well. In the present study, Mg-based hybrid MMnCs have been developed by in-situ reinforcement of MgO and CeO2 particles through the stir casting process. The minimum reinforcement size has been confirmed as 20 nm during transmission electron microscopy (TEM). MMnCs were subjected to high-temperature press forging. Thus,significantly reducing porosity. The evolved texture, mechanical properties were evaluated near the central and peripheral regions of the forged disk. Fractography was carried out to confirm the nature of the fracture. The Central region of disk showed better mechanical properties than peripheral region. The dominant presence of basal texture near the peripheral area led to tensile twinning and, thus, prominent strain hardening during compression. Further, strengthening mechanisms were used to predict the yield strength. It is found that Taylor’s strengthening is the dominant strengthening mechanism.

Hybrid-hybrid turning of micro-SiCp/AA2124 composites: A comparative study of laser-and-ultrasonic vibration-assisted machining

Machining of micro SiCp/AA2124 composites remains a challenge with conventional machining yielding poor surface quality with high tool wear. In this paper, we study two distinct and unique hybrid machining processes with the aim of improving the machining outcome of three types of micro-SiC/AA2124 composites with different particulate volume fractions and sizes. The class of composites studied is available commercially and is being used in industrial applications, thus assessing the machining outcomes becomes even more pertinent. Vibratory machining where the tool is made to vibrate at ultrasonic frequencies, known as ultrasonically assisted turning (UAT), is shown to yield some clear improvements in machining. Next, we incorporate laser assistance with the goal of inducing thermal softening in the process zone. This hybrid-hybrid machining process which is referred to as laser-ultrasonic-assisted turning (LUAT) has the potential for improved machining outcomes with significantly reduced machining forces and surface topology improvement. Our studies indicate that an optimum laser power exists for each type of metal matrix composite considering the particle size and volume fraction of the particulate reinforcements yielding benefits in terms of machining force reduction, surface topology improvement and potentially tool life enhancement. In addition, a computational machining model was developed which can be used to predict the machining outcomes with variable machining parameters.

Investigating the standard sizes of steel reinforcement used in the Ghanaian industry

The study aimed to explore and determine whether the steel reinforcement bars manufactured and used in Ghana meet the standard sizes. The research adopted a positivist philosophy and a market survey approach. The various organizations manufacturing and supplying steel reinforcement were purposively selected and visited, and the different steel reinforcement bars were measured against the standard sizes. When the measured sizes were compared to the standard sizes, the results revealed that all the mild steel reinforcement bars measured did not meet the required standard sizes. The results showed that all the high tensile steel reinforcement bars met the necessary standard sizes in the Ghanaian construction market. The research empirically demonstrated that non-standard steel reinforcement bar sizes impact most project outcomes. The regulatory authority (National Standard Authority) must ensure that both manufactured and imported steel reinforcement bars meet the standard sizes on the construction market in Ghana to keep the project under control and enable the structure to achieve its maximum strength.

Thermal and Structural Behaviour of Sandwiched Reinforced Cement Concrete Wall Panels

The energy efficiency of a building predominantly depends on the temperature gradient across the wall. The use of Sandwiched Concrete Panels (SCP) to achieve energy efficiency inside buildings is gaining importance all over the world. This study focuses on comparing the temperature gradient across sandwich concrete wall panels made of two different insulation materials viz. Extruded Polystyrene (XPS) and Expanded Polystyrene (EPS) with two different sizes of steel (8 mm and 10 mm dia.) used as reinforcement and shear connectors. Two different concrete grades viz. M25 and M40 were studied. The thickness of concrete wythes on both sides of the SCP and the inner insulation material (XPS and EPS) were varied to understand their effect on thermal insulation. The external surface of the samples was subjected to an elevated temperature of 75 °C for 24 hours continuously and the temperature measurements across the SCP were recorded. This was done by simulating the real-time temperature effect using an indigenously developed oven, designed and fabricated to fit the SCP sample size which comprises an electronic thermostat and temperature sensor unit arrangement. Additionally, a one-dimensional finite element analysis was carried out to predict the theoretical interface temperature and inner surface temperature of the SCP samples with necessary assumptions. Both the experimental and FEA temperature values corroborated well. Further, all the samples were subjected to compression and flexural testing to evaluate their structural properties. Influence of type of insulation material used viz. XPS and EPS, size of steel reinforcement used viz. 8 mm and 10 mm dia. were found to be not that significant in terms of both thermal and structural behavior.

Effects of solid-state interfacial reaction on the mechanical properties of carbon nanotubes reinforced aluminum matrix composites with heterogeneous structure

To overcome strength-ductility trade-off in carbon nanotubes (CNTs) reinforced Al matrix composites, we developed a novel and controllable strategy via a combination of different length of CNTs and fine/coarse-grained matrices. Microstructure analysis showed that Al4C3 nanorods about 100 nm were distributed in the fine grain zone (FGZ), while CNTs of micron length were distributed in the coarse grain zone (CGZ). Different sizes of reinforcements play different strengthening roles, and the bimodal grains can effectively coordinate deformation, thereby achieving a good combination of strength and ductility. Heat treatment does not affect the microstructure of the FGZ, but significantly affect the CNT/Al interface bonding in the CGZ. Heat treatment at an appropriate temperature can further improve the strength of the composite by improving the interface bonding. When the heat treatment temperature is too high, the coarsening of Al4C3 in CGZ will deteriorate the mechanical properties of the composite.

Analysis and Modelling of Reinforced Concrete Beams

The work is to understanding the behaviour of structural components like beams and columns during loading is crucial for the development of efficient and safe structures. In this report, the reinforced concrete beam has been analyzed and modelled when subjected to two-point loads and single-point load conditions, using the Finite Element Analysis tool, popularly called ANSYS software. The analyzed and modelled beam has a dimension of 500mm × 100 mm × 100 mm with 2 numbers of 8mm diameter bars are main reinforced, and 2 numbers of 8 mm diameter are hanger bars. The behaviour of the analysed beam has been observed regarding the shear behavior, crack widths and displacement for various static loading. According to the analysis carriedout on the Reinforced Concrete beams using ANSYS, it is observed that results are more profound to reinforcement size, materials properties, load percentage increment, etc.

Evaluation of Wear Behaviour Based on Mechanical Properties and Particle Size in LM26 MMC

Abstract Based on its superior casting and mechanical properties, LM26 is a well-known material in the automobile sector for the manufacturing of pistons for both diesel and gasoline engines. However, cast alloys diminishing the strength at higher temperatures leads to metal matrix composites. The present work deals with fabrication and characterisation of aluminium cast alloy LM26 reinforced with ceramic particles of Almandine Garnet with varying percentages fabricated by dual step stir casting technique The micro hardness and ultimate tensile strength (UTS) were determined and the sliding wear behaviour was estimated using a pin-on-disc apparatus. The effect of particle size and weight fraction of reinforcement on physical and mechanical properties were investigated and collated with unreinforced metal. Wear behaviour of the composite had a reasonably good correlation with composite mechanical properties were also observed. Validation of Experimental results with theoretical values were also discussed.

Effect of laser dwell time on pore elimination in powder bed fusion of metal matrix composites: experimentally validated modeling

Many studies have been conducted to better understand the relationship between additive manufacturing (AM) process parameters and the resulting structure and properties of manufactured parts. It is quite clear that defects associated with AM parts are detrimental to part performance and are thus a major concern for a broader application of AM processed parts. In this study, we aim to investigate the influence of process parameters such as laser dwell time in mitigating pore formation during powder bed fusion of AISI 316L austenitic stainless steel (SS316L)-WC composites. Single-track experiments are conducted with varying printing parameters, while discrete element modeling (DEM) is employed for simulating powder-bed packing for composite system. Results show that the filling of the pores between ceramic particles by the molten SS316L is dependent on the laser dwell time, which in turn, depends on the volume fraction of ceramic reinforcement and initial pore sizes between inclusions. Our experiments, in agreement with model analysis, show that with the information of the materials property of the metal phase in a composite system such as viscosity, surface energy and initial pore sizes between ceramic inclusions, the printing parameters can be chosen to yield the appropriate dwell time for pore free composites.

A literature review on Al-Si alloy matrix based in situ Al-Mg2Si FG-composites: Synthesis, microstructure features, and mechanical characteristics

The current study examined a comprehensive review of the literature on functionally graded composites, particularly Al-Mg2Si in situ metal matrix composites. Functionally graded Al-Si-Mg2Si in situ metal matrix composites are potential materials for meeting a variety of property demands in various components of automotive engines. The in situ formed intermetallic compound Mg2Si in Al-Si matrix exhibits a high melting temperature, low density, high hardness, a low thermal expansion coefficient, and a reasonably high elastic modulus. Due to all of aforementioned characteristics, Mg2Si is an attractive form of reinforcement that can be created in situ using a simple melt reaction approach. However, the coarse size of primary Mg2Si reinforcement in cast composites is a demerit which reduces the strength and ductility of the ultimate composite. Hence several researches have been attempted to refine the primary Mg2Si particles as well as to change the morphology of the eutectic structure. Apart from the monolithic in situ cast composites, attempts have been made to develop functionally graded (FG) composites in which the volume% of segregation of reinforcements are intentionally varied from one surface to another. These types of FG composites are economically developed by centrifugal casting technique in which Mg2Si reinforcements are segregated to inner the surface due to lower relative density with respect to the molten Al matrix. This type of graded microstructure results in higher strength, hardness and wears resistance at the inner surface of the tubular products. The as-cast microstructure and properties are significantly improved by solution treatment and aging. In the last, some of the most recent manufacturing techniques for FG-composites are addressed, along with their benefits, drawbacks, and applications. In general, all cutting-edge and detailed surveys of the present state of knowledge are included in this article.

Vibration characteristics of sandwich plates with GPLRC core and piezoelectric face sheets with various electrical and mechanical boundary conditions

An analysis is performed in the current investigation to study the vibrations of composite laminated plates integrated with piezoelectric layers. Composite laminated plate is reinforced with graphene platelets (GPLs). Also the amount of GPLs in the layers may be different which results in a piecewise functionally graded (FG) media. Elasticity modulus of the GPLRC media is obtained by means of the Halpin-Tsai rule which contains efficiency parameters to capture the size of reinforcements. First order shear deformation theory of plates and parabolic distribution of electric field through the piezoelectric layers are assumed as the basic assumption. For the piezoelectric layers, both the open circuit and closed circuit conditions are applied. The total strain and kinetic energies of the plate are obtained. After that by means of the general idea of the Ritz method and also Chebyshev polynomials as the basic shape functions, the matrix representation of the equations of motion dealing with free vibration of sandwich plate with piezoelectric face sheets are obtained. Results of this study are first compared with the available data in the open literature. After that novel results are given to explore the effects of different parameters such as the electrical and mechanical boundary conditions, plate geometry, GPL weight fraction and GPL distribution profile. It is shown that with introduction of GPLs, frequencies of the plate may be enhanced for both closed circuit and open circuit conditions.

High temperature and strain-rate response of AA2124-SiC metal matrix composites

This paper presents the results of the study of the dynamic impact behaviour of the AA2124-SiC Metal Matrix Composite (MMC) material with different particle reinforcement sizes and qualities using a compressive Split-Hopkinson Pressure Bar (SHPB) apparatus. Mechanical tests were performed at strain rates 1000 s−1, 2000 s−1, and 3000 s−1 and at temperatures of room temperature (25 °C), 100 °C and 200 °C. Microstructural analyses were carried out on the samples pre and post-compression experiments to study the fracture characteristics and mechanisms of the MMC materials. The flow stress-strain, strain rate, temperature effects and deformation mechanism were investigated. The backscattered electron images show that a higher strain rate of deformation induces the formation of denser and smaller grain size of CuAl2 precipitates, especially in composites with smaller SiC particle sizes. Temperature has posed a minor effect on the microstructural change. Heating the samples close to a solution treatment temperature, and then followed by an air quenching has resulted in a fine dispersion of CuAl2 precipitates, as well as a high saturation for the materials with a higher volumetric fraction of SiC reinforcement. The SHPB compression results reveal that the 225XF material has developed the highest stress among all materials. For materials with a higher volumetric fraction of SiC reinforcement (225XE and 225XF), cracks and failures have appeared in the samples during high strain rate and high-temperature compression experiments, which is believed to be caused by the increased brittleness of the material as a result of intensified oxide phases.

Synergistic reinforcement effect of Fe and in-situ synthesized MgAlB4 whiskers in Al matrix composites

Interfacial bonding is an important factor affecting the mechanical properties of composites. The interface between the in-situ synthesized ceramic phase and the metal matrix is considered ideal, so little attention is paid to the interfacial modification. In this work, we found that interfacial segregation affects the growth of the MgAlB4 whisker and the interface of reinforcement and matrix in the composites. Systematic experiments and theoretical calculations indicate Fe solute prefer to segregate at the MgAlB4-{101‾0}/Al interfaces in in-situ synthesized MgAlB4/Al composites, which is helpful to reduce system free energy. On the one hand, Fe segregation induces the whisker coarsening and the formation of planar defects with a sandwich structure formed by a layer of Fe atoms and two layers of Al atoms in coarse-whiskers, on the other hand, it improves the interfacial strength. Although extra Fe aggravates the whisker coarsening, the synergistic reinforcing effect of the whiskers and the extra Fe is greater than the sum of their individual reinforcing effects. This work demonstrates that interfacial segregation can be used to modulate the size of reinforcements and improve interfacial strength.

Efficacy of staple line reinforcement by barbed suture for preventing anastomotic leakage in laparoscopic rectal cancer surgery.

BACKGROUNDAnastomotic leakage (AL) is a severe complication in rectal cancer surgery. Various methods, including intracorporeal reinforcing suturing, have been used to reduce the incidence of AL. However, little is known about the efficacy of staple-line reinforcement by barbed suture for preventing AL.AIMTo evaluate the efficacy of staple-line reinforcement using barbed suture for preventing AL in laparoscopic surgery for rectal cancer.METHODSWe retrospectively reviewed the clinical datum of 319 patients undergoing laparoscopic low anterior resection combined with double stapling technique between May 1, 2017 and January 31, 2021. All surgeries were performed by the same surgical team specializing in colorectal surgery. Patients were divided into two groups depending on whether they received reinforcing sutures. Patients’ baseline characteristics did not show any significant difference between the two groups. We analyzed patient-, tumor-, as well as surgery-related variables using univariate and multivariate logistic analyses. RESULTSThere were 168 patients in the reinforcing suture group and 151 patients in the non-reinforcing suture group. AL occurred in 25 cases (7.8%). Its incidence was significantly higher in the non-reinforcing suture group than in the reinforcing suture group (4.8% vs 11.3%, P = 0.031). The multivariate analyses demonstrated that the tumor site, tumor size and presence of staple-line reinforcement were independent risk factors for AL. We divided these patients into two risk groups based on the combination of tumor site and tumor size. Patients without any risk factor were assigned to the low-risk group (n = 177), whereas those having one or two risk factors were assigned to the high-risk group (n = 142). In the high-risk group, the AL incidence considerably decreased in the reinforcing suture group compared with that in the non-reinforcing suture group (P = 0.038). Nonetheless, no significant difference was found in the low-risk group between the two groups.CONCLUSIONStaple-line reinforcement by barbed suture may decrease the incidence of AL. A large-scale prospective randomized controlled trial is needed for evaluating the efficacy of staple-line reinforcement for preventing AL.

Effect of Sintering Temperatures, Reinforcement Size on Mechanical Properties and Fortification Mechanisms on the Particle Size Distribution of B4C, SiC and ZrO2 in Titanium Metal Matrix Composites.

Titanium metal matrix composites/TMMCs are reinforced ceramic reinforcements that have been developed and used in the automotive, biological, implants, and aerospace fields. At high temperatures, TMMCs can provide up to 50% weight reduction compared to monolithic super alloys while maintaining comparable quality or state of strength. The objective of this research was the analysis and evaluation of the effect/influence of different sintering temperatures, reinforcement size dependence of mechanical properties, and fortification mechanisms on the particle size distribution of B4C, SiC, and ZrO2 reinforced TMMCs that were produced and fabricated by powder metallurgy/PM. SEM, XRD, a Rockwell hardness tester, and the Archimedes principle were used in this analysis. The composites’ hardness, approximation, tensile, yielding, and ultimate strength were all increased. As the composite was reinforced with low-density ceramics material and particles, its density decreased. The volume and void content in all the synthesized specimens is below 1%; this is the result of good sample densification, mechanical properties and uniform distribution of the reinforced particle samples; 5% B4C, 12.5% SiC, 7.5% ZrO2, 75% Ti develop higher mechanical properties, such as higher hardness, approximation tensile, yielding, and ultimate strength and low porosity.

Performance improvement of ballasted railway tracks using three-dimensional cellular geoinclusions

Three-dimensional (3D) cellular inclusions such as geocells and scrap rubber tyres improve the engineering properties of the infill materials by providing all-around confinement. Although the 3D geoinclusions possess immense potential in the railway industry, their application is still limited due to a lack of adequate techniques to evaluate the magnitude of improvement provided by these artificial inclusions. This article presents an innovative computational approach to evaluate the effectiveness of 3D cellular geoinclusions in improving the performance of ballasted railway tracks. The proposed method is an integrated approach that combines the additional confinement model with the geotechnical rheological model for a railway track. The methodology is applied to an open track-bridge transition, and the results revealed that the geoinclusions substantially reduce the differential settlement. However, the magnitude of improvement depends on the opening size, placement location within the track and material used to manufacture the cellular inclusions. Moreover, the magnitude of settlement reduction also depends on the axle load and subgrade soil properties. The proposed methodology can assist the railway engineers in assessing the efficacy of 3D inclusions in improving the performance of railway tracks and help select the most appropriate material, size, and location of reinforcement for deriving maximum benefits.