Reinforcement Size Research Articles

Experimental Study on the Performance of Mechanical Coupler Splice Made of Rebar Under Monotonic Loading

The lap splice method presents a drawback due to reinforcement congestion, affecting the pouring and evenness of the concrete. Additionally, lap splicing significantly contributes to construction waste. As a result, research was conducted on mechanical connections using reinforcements to reduce construction waste and demonstrate the feasibility of these splices. In this study, the threaded coupler with standard national coarse threads splice method was employed, and tests were conducted following ASTM A1034-10a standards with monotonic tensile loading. Test specimens were created using 13 and 16 mm reinforcement sizes, varying the length and diameter of the coupler, and including welding at the coupler ends. The test results demonstrated that reinforced bars with splices exhibit a stress-strain relationship similar to intact reinforcement. However, these reinforced bars with splices did not meet the requirements outlined in SNI 2052:2017 concerning maximum stress and strain, including their comparison. Therefore, the utilization of these splices is not suitable for critical load-bearing areas.

Effect of hybrid eco‐friendly reinforcement and their size on mechanical and flame retardant properties of polypropylene composites for technical applications

AbstractWhile the potential of natural fiber (NF) composites for various engineering applications is well‐recognized, a deep understanding of the intricate interactions within these composites remains crucial. This study examines the microstructural characteristics of the polymer matrix and evaluates the impact of reinforcement size, with a particular focus on fire sensitivity. Hybrid‐reinforced polypropylene (PP) composites were introduced using a unique tri‐hybrid system. This system combines long flax fibers (LFF) as primary reinforcement, with short basalt fibers (BF) and micro rice husk powder (RHP) as secondary reinforcements. These composites were fabricated using innovative extrusion, compression, and injection molding techniques. This novel fabrication method and strategic hybrid design bridged gaps in the composite structure, leading to significant enhancements in tensile and flexural strength. Improvements of 57.82%, 67.53%, and 60.02% over LFF/PP composites were observed, respectively. On the thermal front, the char residue surged by an impressive 497.51%. Flame properties, notably pHRR and THR, were reduced by 57.25% and 13.28%, respectively. These enhancements are attributed to the lignin in BF and the silica in RHP. The fire safety index further confirmed these improvements, with FGI and FPI increasing by 27.33% and 111.11%, respectively.

Effect of microstructure on the effectiveness of hybridization on additively manufactured Inconel718 lattices

This work aims to investigate the effect of the material microstructure on the effectiveness of hybridization in additively manufactured Inconel718strut-based lattices. Two microstructures, namely the as-built solid solution and a peak aged condition, are coupled with three hybrid architectures formed by alternating face centred cubic (matrix) and octet-truss (reinforcement) domains containing 1, 8, and 64 unit cells. Digital image correlation is utilized to map the local strain distribution during compression, and finite element analysis is utilized to map stress localization. It is shown that in the as-built condition the mechanical behavior of all the hybrid lattices was very similar to that of the single-oriented components, irrespective of the reinforcement size. In the peak-aged lattices, on the contrary, including octet-truss reinforcements of sufficiently small size resulted in an increase inmechanical stability, damage tolerance, and absorbed energy, as interphase boundaries act as obstacles to shear band propagation. It is also shown that effect of hybridization is a function of the size of the reinforcements. In particular, below a critical size, the lattice behaves as a reinforced “single-phase” structure, rather than a two-phase architecture. This work defines guidelines for the design of robust lattices manufactured by laser powder bed fusion.

Role of Particle Size of Al2O3 Reinforcement on the Wear Performance of NiTi-Based Composites

Role of Particle Size of Al2O3 Reinforcement on the Wear Performance of NiTi-Based Composites

Experimental evaluation of axial compression performance of precast panels from bamboo-reinforced concrete

This research aimed to determine the performance of bamboo-reinforced concrete precast panels (BRCPP) subjected to axial compressive loads, validated using numerical simulations. Axial compressive load capacity, crack, and failure patterns were investigated and compared with steel-reinforced concrete precast panels (SRCPP) as a control. Eight panels were made with details of four BRCPP and SRCPP, having dimensions of 1200 × 400 × 50 mm3 each. The four SRCPPs consisted of two panels, produced in laboratories and two manufactured by local companies. The variations in bamboo reinforcement spacing were 150 mm and 180 mm, while the gap between steels was 180 mm, and panels were tested under axial compressive load. The results showed that the axial compressive load capacity of BRCPP with a bamboo reinforcement size of 12 × 12 mm2 at a distance of 150 mm was sufficient to meet the specifications of SRCPP panels produced by the local industry. Based on experimental, theoretical, and numerical simulation analysis, the performance of BRCPP showed suitability, making it a considerable choice, specifically for precast panels. The special advantage of BRCPP encompassed eco-friendliness and sustainability.

Influence of Ti particle sizes on microstructure and mechanical behaviors of AZ91-Ti composites under different loading paths

Magnesium (Mg) matrix composites are recognized as the most promising light structural materials and have been extensively investigated, but they still suffer from a relatively low ductile nature which seriously affects their further development. Herein, the Mg–9Al–1Zn (AZ91) Mg matrix composites with different sizes of Ti particles reinforcement can be obtained via hot pressed sintering followed by hot extrusion. The microstructure demonstrated that the interfacial region is consisted of Mg17Al12 and Al-rich phase. Uniaxial tensile experiments revealed that the AZ91-Ti (particle size of 15 μm) composite achieves the optimal comprehensive mechanical properties, and the corresponding yield strength (YS), ultimate tensile strength (UTS), elongation (EL) of the composite can reach the high values of 210 MPa, 310 MPa, 15.5%, respectively. Moreover, with the decrease of Ti particle size, grain refinement and the strong interfacial bonding between Ti particles and Mg matrix render as-prepared the composites exhibited outstanding mechanical properties. Ti reinforcement particles of appropriate size can alleviate the plastic strain accumulation during the tensile and compressive cyclic loading, so that the excellent ductility of the composite is obtained. Constitutive relation of AZ91-Ti composites in this experiment can be derived from the nonlinear elastic relation. The simulated stress-strain curves of the composites reinforced by Ti particles with different sizes are consistent with the experiment.

Effect of Geogrid Reinforcement and Soil Relative Density on Performance and Contact Pressures of Ring Foundations on Sand

Reinforcing soil beneath foundations is one of the standard methods to improve the foundation performance. However, soil relative density may affect the efficiency of reinforcement. This experimental study has been conducted on a model ring foundation resting on medium, dense, and very dense geogrid-reinforced sand. For this purpose, 17 tests were carried out to evaluate the effect of soil density and reinforcement depth and size on bearing capacity and settlement of the ring foundation and its normal contact pressure distribution. The results show that geogrid-reinforced sand with higher relative densities improves bearing capacity and decreases settlements significantly. It can be shown that implementing a geogrid layer that is equal to the dimensions of the footing is cost-effective. The scale effect analysis has been conducted for the model foundation, sand, and geogrid used in this research. Additionally, normal contact pressure distributions for unreinforced and reinforced sand are presented. Decreasing the depth of reinforcement transforms the form of normal contact pressure distribution from saddle to parabolic.

Experimental study and small-sample-regression prediction on effect of carbon-based reinforcements on thermal conductivity of composite mortar

To reveal the impact of various sizes of inert reinforcement on the pore structure, hydration products, and microscopic morphology of mortar. To explore its effect on mortar's thermal conductivity. Investigated by microscopic tests and small sample regression modeling. It is found that nanoscale materials have a nanocore effect, which can effectively enhance hydration, but the filling and bridging of larger pores is inadequate, leading to lower thermal conductivity in the early stage. The release of their properties is limited by the dispersion technique. Micron-reinforcing-phase, easily dispersed and with adsorption, can effectively fill capillary pores, and adsorb the hydration products to advance the hydration process. Milli-reinforcing-phase, flocculent fiber water absorption is obvious, resulting in the reduction of the real water-cement ratio, hydration process is delayed. With age growth and water precipitation, the fiber surface produces nucleation sites, which will accelerate the hydration rate. For thermal conductivity, porosity is the main influence factor in the early curing stage; when the porosity changes are small, the internal microstructure and hydration products will become the dominant factors. The sample set is expanded by feature enhancement and data synthesis to improve the generalization ability. The predicted model R2 can reach 0.75, demonstrating that a limited sample of experimental data can make reliable predictions.

Effect of ceramic reinforcements on the mechanical and tribological properties of aluminium metal matrix composites – A review

Aluminium alloys were previously used by industries worldwide because of their excellent mechanical properties over other metallic alloys. However, the need for improved performance has shifted the focus to composites. Researchers have fabricated composites with various aluminium alloys as the base matrix and different ceramic particulate as the reinforcements. These aluminium metal matrix composites (AlMMCs) were fabricated using various manufacturing processes such as stir casting, friction stir processing, accumulative roll bonding, in-situ synthesisation using halide salts and pressure infiltration. This review article analyses the work carried out by researchers in the area of AlMMCs and summarises the effect of reinforcement type, reinforcement size and percentage proportion of reinforcements, on the mechanical and the tribological properties of AlMMCs.

Comparative analysis between size and mass ratio of nano-Al2O3 in the performance of dental composite and finding the optimum composition

Dental composites provide better bonding with tooth tissue as compared to other traditional materials such as amalgam. However, the development of dental composites relies on experimental results of physical, mechanical and thermal properties of the dental composite obtained after applying the strategy of filler technology, i.e., changing size, shape, surface modification and mass ratio of filler or reinforcement. In the present research, nano-Al2O3 particle size and filler mass ratio were varied to study their effect on the physical, mechanical and thermal behaviour of dental composite. The particle size was varied in the range of 30 nm, 50 nm and 70 nm. Nano-Al2O3 filler mass ratio was varied in the range of (0, 5, 10 and 15 wt. %). Fourier transform infrared analysis was done to check variations in absorption peak and band in the spectrum due to variation in the filler mass ratio and size. Physical properties, mechanical properties and thermal properties were investigated. It was observed that hardness, compressive strength, diametral tensile strength, flexural strength and stress intensity factor were increased by 133%, 13.6%, 27.4%, 25% and 20%, respectively, on adding 5 wt. % of nano-Al2O3 and decreased by 13.5%, 8.1%, 15.3%, 13.9% and 10.3%, respectively, on increasing particle size from 30 nm to 50 nm. The thermal degradation temperature was increased by 31.8% and 36% on adding 5 wt. % and increasing particle size from 30 nm to 50 nm, respectively. It can be concluded that in the case of nano-sized particulate filler, mass ratio played a more significant role than filler size in regards to optimization of physical, mechanical and thermal properties.

Spark plasma sintering of ceramic-reinforced binary/ternary nickel and titanium metal matrix composites: Mechanical properties, microstructure, and densification – A review

Spark Plasma sintering is an excellent technique for developing ceramic-reinforced binary/ternary nickel and titanium metal matrix composites (MMCs). This review analyzes the mechanical properties, microstructure, and densification characteristics of SPS-produced composites. Introducing ceramic reinforcement such as carbides, oxides, nitrides, or borides enhances the mechanical characteristics and functionality of MMCs. The SPS method has advantages such as high heating rates, low processing durations, and relatively low sintering temperatures, all of which assist in reducing reactivity concerns and retaining the desirable properties of the matrix and reinforcing materials. The impact of different process parameters such as temperature, pressure, heating rate, and holding time on the final microstructure and densification of the composites was discussed in this review. Additionally, it examined how different types, contents, and particle sizes of reinforcement affected the mechanical qualities, including hardness, tensile strength, fracture toughness, and wear resistance. Furthermore, the production of secondary phases and the interfacial bonding between the matrix and reinforcements are explored because they significantly affect the mechanical performance and behavior of the composites. This work contributes to an extensive understanding of the SPS procedure for ceramic-reinforced nickel and titanium MMCs, offering insightful information on processing parameters that enhance production and modify the characteristics of these technologically advanced materials for many applications in the aerospace, automotive, and structural industries.

Electrochemical study of aluminum–cubic boron nitride composites synthesized via spark plasma sintering for engineering applications

Herein, aluminum−cubic boron nitride (Al−BN) composites with different reinforcement sizes (20, 40, and 60 µm) were developed via spark plasma sintering while maintaining a constant weight percentage (10 wt%; reinforcement). The powder materials were sintered at a temperature of 550 °C and constant uniaxial pressure of 50 MPa with a heating rate of 100 °C/min. Field-emission scanning electron microscopy analysis of the developed composites revealed a uniform dispersion in the Al matrix. X-ray diffraction analysis indicated the presence of aluminum and cubic boron nitride major and minor phases, respectively. Evidence of chemical reactions and the presence of an interfacial phase were not observed at 550 °C in the Al−cBN composite. The mechanical and electrochemical properties of the composites were investigated as a function of the cBN particle size. The results demonstrated that the composite with a cBN particle size of 20 µm (i.e., more particles in the Al matrix than other compositions) strengthens the matrix owing to the better stress drive in the matrix and exhibits the highest average hardness (1.78 GPa), elastic modulus (76.1 GPa), and percentage of densification (98.1%) compared to the other tested composites. The corrosion behavior and resistance against pitting corrosion of pure Al and cBN-based composites were investigated in a 3.5 wt% NaCl solution using electrochemical techniques, such as open circuit potential, electrochemical impedance spectroscopy, and cyclic potentiodynamic polarization analyses. Electrochemical studies revealed that among the analyzed samples, the composite with 20 µm cBN particles exhibits an excellent polarization resistance, in addition to the lowest corrosion rate (∼5 mills per year) and a very high resistance to pit formation in a corrosive environment.

Structural analysis of Cu-based FeCr reinforced composites prepared by mechanical alloying

Abstract Production and structural investigations of Cu-based FeCr reinforced composite were performed by using mechanical alloying, optical microscope, scanning electron microscope, X-ray diffraction and hardness test. The increment in FeCr addition caused the increment in the cold deformation rate. This situation resulted in breakage of the powder particles throughout mechanical alloying. Thus, the grain dimension of the FeCr powders decreased and the Fe wt.% in the CuCr powders advanced. The collision force between the Cu-Cr powder and the grinding ball weakened with the increase of FeCr concentration and resulted as higher reinforcement size. After mechanical milling, FeCr grains decreased in size more than copper grains due to the ductility of copper grains. The smaller crystals occurred after grinding, and increased the grain boundary zone for further spread of Cr into the Cu. Despite the high sintering process, the high sintering temperature improved the compactness of the alloys, but caused coarsening of the nanoparticles. The mechanical alloying time, reinforcement wt.% and sinter temperature were effective on the micro-hardness of the microstructure.

A future prospects and current scenario of aluminium metal matrix composites characteristics

This paper provides a synergistic review of the current scenario and future prospects of aluminum metal matrix composites (AMMCs). AMMCs are advanced materials that have garnered significant attention in recent years due to their unique characteristics, including high strength, low density, and excellent wear resistance. This review covers various aspects of AMMCs, including processing techniques, mechanical and physical properties, microstructural features, and applications. The review begins with an overview of different processing techniques for AMMCs, including stir casting, powder metallurgy, and infiltration methods. It then discusses the mechanical and physical properties of AMMCs, such as tensile strength, hardness, and thermal conductivity, and how these properties are influenced by various factors such as reinforcement type, size, and volume fraction. Furthermore, the microstructural features of AMMCs, including the distribution of reinforcements, are discussed in detail. The review also highlights the potential applications of AMMCs in various industries such as aerospace, automotive, and electronics. Finally, the review concludes by discussing the current scenario and future prospects of AMMCs. It highlights the challenges that need to be addressed to enhance the performance of AMMCs and the potential areas of research that could lead to the development of advanced AMMCs with superior properties. Overall, this review provides a comprehensive overview of the current status and future prospects of AMMCs and highlights the importance of continued research and development in this field.

A micromechanical model of multi-scale nano-reinforced composites

Nano-reinforced composites have a wide range of useful applications thanks to their exceptional all-encompassing characteristics. Understanding the micromechanical model and the reinforcing process in nano-composites is crucial for a quantitative assessment of the reinforcement impact of nano-fillers and performance optimization. The original micromechanical model for common composite materials is no longer applicable since mechanical modeling of composite materials takes into consideration variables like multi-scale, multi-phase, and multi-morphology. The multi-scale parameter equivalent modeling theory of nano-reinforced composites is examined in this work. It is suggested to use a generalized modified Halpin-Tsai micromechanical model, which may accommodate any reinforcement form, size, or orientation, after theoretical and experimental comparison and verification. A tiny sample of the nano-reinforced composite material's mechanical tensile characteristics was examined, and its microscopic.

Role of matrix alloy, reinforcement size and fraction in the sliding wear behaviour of Al-SiCp MMCs against brake pad material

Aluminium metal matrix composites were produced by a newly developed stirring device for stir casting with different matrix alloys, SiC particle fractions and sizes to investigate these parameters' influence on the materials' wear performance. The wear performance of the composites was evaluated with dry sliding pin-on-plate tests against a high-speed train brake pad, and the study of wear surfaces was completed by electron microscopy. The formation of an iron-based tribolayer during wear protected the metal matrix composite from further wear damage. The composite reinforced with 19% SiC particles sized 32 μm showed an increasing coefficient of friction during wear, and the wear surface showed traces of third body wear. The rare earth and transition metal added to the matrix alloy increased the hardness of the composite, and the intermetallic phases reduced the development of the Fe-based tribolayer. The composites with small SiC particles presented the Fe transfer on the exposed aluminium surface, with a lower wear rate and friction coefficient than other composites. The direct comparison of composites produced with different sizes of SiC particles highlighted that the relationship between the wear rate and the coefficient of friction of the composites and the brake pad showed a linear trend.

Gaussian filtering method of evaluating the elastic/elasto-plastic properties of sintered nanocomposites with quasi-continuous volume distribution

In this work, combing the Gaussian filtering algorithm and the cutting quantile functions, a new technique is developed to efficiently generate the RVE of randomly distributed metal matrix nanocomposites (MMNCs) with quasi-continuous volume distribution. The procedures of filtering the random point matrix, generating the random field, separating the spatial points into constituents, and imposing the periodic boundary conditions are numerically implemented in detail. By contrasting the elastic/elasto-plastic properties of the sintered AgNPs composites with those determined by experimental measurements and analytical models, the proposed numerical homogenization model is verified. The results show that the proposed algorithm can control the distributions of the reinforcement size and the matrix volume fractions by tailoring the Gaussian widths and cutting levels. Meanwhile, the ratio of the Gaussian widths to the RVE length σ/L make influences on the resulting elastic/elasto-plastic properties of the MMNCs, and for the sintered AgNPs composites, σ/L = 2.5 is the critical value of its convergence. Additionally, the proposed method can be also extended to predict the other physical properties of MMNCs including conduction and diffusion.

Effect of Local Remelting and Recycled WC-Co Composite Reinforcement Size on Abrasive and Erosive Wear of Manual Arc Welded Hardfacings

The hardfacings reinforced by recycled (cermet inserts of machining tools) WC-Co composite particles applied by manual arc welding can be used for protection against abrasive and erosive wear. Two categories of coatings were analyzed: with and without thermal treatment (local remelting). The hardfacings were tested under abrasive (low and medium stress) and erosive (high stress) conditions. In elevated temperature erosive conditions, coatings without heat treatment have up to two times higher wear resistance than reference material. Under low-stress conditions, coatings with the finest reinforcing particle size (180–355 µm) treated with local remelting demonstrated more than 10 times higher wear resistance than reference material. The optimal reinforcement size selection depends on the application conditions (low, average, or high stress). In most test conditions, the local remelting did not provide additional improvement. A scanning electron microscope was used for the characterization of wear mechanisms. The relation between mechanical properties and wear rates was found only for some conditions.

Assessing the role of reinforcement size and weight percentage on the mechanical and wear characteristics of Al7050‐TiO2‐hBN hybrid composites

In the present study, hybrid composites of Al7050 reinforced with TiO2 (1, 3 and 5%) and hexagonal boron nitride (hBN, 2, 4 and 6%) have been developed by using two different sized reinforcing particles (∼ 40 μm and ∼ 20 μm) through stir casting route with an aim to investigate the role of particles size within the micrometer level on mechanical and wear characteristics. From the microhardness measurements, higher hardness was measured for the composites with the increased content of the reinforcement. Similar trend was observed for the composites with both the reinforcement sizes. From the impact strength measurements, more values were observed for the composites having 20 μm sized reinforcements. With the increased fraction of hBN (6%), no significant improvement in the impact strength was noticed for the composites with 40 μm sized reinforcements. On the other hand, significant increase in the impact strength was measured for the composites with 20 μm sized reinforcements. Increased tensile strength (from 95 ± 4.6 up to 156.8 ± 6.1 MPa) with the higher fraction of reinforcements was measured at the cost of losing ductility as reflected in the decreased % of elongation (from 15.2 to 11.65). With the decreased size of reinforcement from 40 to 20 μm, the composites exhibited more strength and lower ductility. From the wear studies, it was clearly observed a decreased trend in the wear rate and increased coefficient of friction with the increased reinforcement content. Compared with 40 μm reinforcements, adding 20 μm sized reinforcements has shown higher level of impact on reducing the wear rate. The results demonstrate that the size difference of reinforcing particles in the level of a few micrometers also significantly affects the performance of the composites.

Effect of defects and reinforcements on the mechanical behaviour of a bi-layered panel

This paper investigates the mechanical behaviour of a bi-layered panel containing many particles in one layer and demonstrates the size effect of particles on the deflection. The inclusion-based boundary element method (iBEM) considers a fully bounded bi-material system. The fundamental solution for two-jointed half spaces has been used to acquire elastic fields resulting from source fields over inclusions and boundary-avoiding multi-domain integral along the interface. Eshelby’s equivalent inclusion method is used to simulate the material mismatch with a continuously distributed eigenstrain field over the equivalent inclusion. The eigenstrain is expanded at the centre of the inclusion, which provides tailorable accuracy based on the order of the polynomial of the eigenstrain. As a single-domain approach, the iBEM algorithm is particularly suitable for conducting virtual experiments of bi-layered composites with many defects or reinforcements for both local analysis and homogenization purposes. The maximum deflection of solar panel coupons is studied under uniform vertical loading merged with inhomogeneities of different material properties, dimensions and volume fractions. The size of defects or reinforcements plays a significant role in the deflection of the panel, even with the same volume fraction, as the substrate is relatively thin.