Experimental Investigation Of Mechanical Properties Research Articles

Experimental investigation of mechanical properties and multi-objective optimization of electronic, glass, and ceramic waste-mixed concrete.

The utilization of waste from various sources plays an important role in minimizing environmental pollution and civil construction costs. In this research, the mechanical properties of concrete were studied by mixing electronic waste (EW), glass powder (GW), and ceramic tile waste (CW). The effects of weight percentages of EW, GW, and CW are considered to investigate improvements in mechanical properties such as compressive strength (CS), split tensile strength (STS), and flexural strength (FS) of concrete. Taguchi analysis has been applied to predict the optimum composition of waste mixing percentages. The Multi-Objective Optimization Ratio Analysis (MOORA) techniques are applied to estimate the optimum composition of mixing wastes for maximizing the CS, STS, and FS of concrete. It was observed that 10 wt.% of EW, 15 wt.% of GW, and 30 wt.% of CW are predicted as the optimal mixing combinations to obtain a maximum compressive strength of 48.763 MPa, a split tensile strength of 4.178 MPa, and a flexural strength of 7.737 MPa, respectively. Finally, the predicted optimum waste-mixed weight percentages were used to examine the microstructure and various elements in the concrete using SEM and XRD analysis. When compared to conventional concrete, the optimum waste-mixed concrete has improved its compressive strength (38.453%), split tensile strength (41.149%), and flexural strength (36.215%).

Experimental Investigation of Mechanical Properties of Geo–Polymer Concrete Using Flyash

Experimental Investigation of Mechanical Properties of Geo–Polymer Concrete Using Flyash

Experimental investigation of mechanical properties of GGBS-FA-SF blended geopolymer concrete at elevated temperatures

Geopolymer has excellent mechanical properties at elevated temperatures, but geopolymer concrete may not be so because of the large difference in thermal properties between geopolymer and aggregate which could lead to substantial thermal stresses when they are in a high temperature environment. In this paper we present an experimental investigation on the mechanical properties of GGBS-FA-SF blended geopolymer concrete with and without steel fibres at elevated temperatures. The influences of exposure temperature, coarse aggregate and steel fibre on the failure mode, compressive strength, elastic modulus, peak strain, and ductility of the geopolymer mortar and geopolymer concrete are examined. Based on the experimentally obtained data, empirical temperature-dependent stress-strain constitutive equations are also proposed, which can be used for the fire safety analysis and design of geopolymer concrete with and without steel fibres.

Modeling and experimental investigations of mechanical properties of hybrid composite rods with gradient composition

The concept of creating a functionally gradient material characterized by a smooth change in composition was used in the fabrication of hybrid composite rods. A hybrid core structure with a glass fiber core and a carbon fiber shell was adopted as the basis. To reduce the risk of delamination at the core-shell interface, a gradual transition was implemented from the core of the rod, made based on high-modulus fiber, to the outer shell composed of low-modulus fiber. The strength and modulus of elasticity in bending for hybrid composite rods were modeled. Using the proposed model, an optimal scheme for distributing glass and carbon fibers across the cross-section of a composite rod was selected. Hybrid composite rods with a diameter of 25 mm, with the same matrix (31±0,1%) and fiber (69±0,1%) content, but with different distribution patterns of glass and carbon fibers along the cross-section, were manufactured via pultrusion technique. The bending strength and stiffness characteristics of composite rods were experimentally determined. Mechanical properties of rods with different reinforcement schemes were compared: homogeneous, core-shell, single, and double gradient. The results indicate that a hybrid rod with a gradient reinforcement scheme exhibits higher values of strength and modulus of elasticity during bending. The modulus of elasticity of the rod with the "double gradient" structure was 103 GPa, for comparison, the modulus of elasticity of the rod made by the "core-shell" scheme was 82 GPa. The simulation aligns well with the experimental data.

Experimental Investigation of Mechanical Properties and Failure Mechanisms in Jute-Polyester Composite Laminates under Off-Axis Tensile Loading

Experimental Investigation of Mechanical Properties and Failure Mechanisms in Jute-Polyester Composite Laminates under Off-Axis Tensile Loading

Experimental investigation of mechanical properties of roller compacted concrete pavement (RCCP) reinforced with date palm fibres

The mechanical properties of roller compacted concrete pavement (RCCP), reinforced with date palm fibres, were investigated for the first time in this study. Date palm fibres extracted from the trunk of date palm trees located southeast of Iran (Yazd), cut into 20 mm and chemically treated were used. After curing for 28 days, cylindrical specimens were conducted to tests such as compressive strength and splitting tensile strength, while flexural strength and toughness index tests were carried out on prismatic specimens using the four-point flexure method. The results of the conducted tests indicated that the maximum flexural strength and splitting tensile strength were increased by 11.68% and 16.83%, respectively in the specimens containing 500 g/m3 of date palm fibres. Moreover, adding 750 g/m3 of date palm fibres resulted in a maximum toughness index of 1.188 among the specimens, which was a remarkable increase over the control specimen.

Experimental Investigation of Mechanical Properties of Concrete Mix with Lightweight Expanded Polystyrene and Steel Fibers

The demand for lightweight aggregates in concrete compositions for diverse structural and non-structural applications in contemporary building construction has increased. This is to achieve a controllable low-density lightweight concrete, which reduces the overall structural weight. However, the challenge lies in achieving an appropriate strength in lightweight concrete while maintaining a lower unit weight. This research aims to evaluate the performance of lightweight concrete by integrating expanded polystyrene (EPS) as a partial replacement for coarse aggregate. Test specimens were cast by blending EPS with coarse aggregate at varying proportions of 0%, 15%, 30%, and 45%, while maintaining a constant water-to-binder ratio of 0.60. To enhance the bonding and structural capabilities of the proposed lightweight concrete mixes, reinforcement with 2% and 4% steel fibers by volume of the total concrete mix was incorporated. Silica fume was introduced into the mix to counteract the water hydrophobicity of EPS material and enhance the durability of lightweight concrete, added at a rate of 10% by weight of cement in all specimens. A total of 60 samples, including cylinders and beams, were prepared and cured over 28 days. The physical and mechanical properties of the lightweight EPS-based concrete were systematically examined through experimental testing and compared against a standard concrete mix. The analysis of the results indicates that EPS-based concrete exhibits a controllable low density. It also reveals that incorporating reinforcement materials, such as steel fibers, enhances the overall strength of lightweight concrete.

Experimental Investigation of Mechanical Properties in Friction Stir Welding for Butt Joints with Different Thicknesses Using Response Surface Methodology

Experimental Investigation of Mechanical Properties in Friction Stir Welding for Butt Joints with Different Thicknesses Using Response Surface Methodology

Experimental investigation of mechanical properties of jute/hemp fibers reinforced hybrid polyester composites

AbstractOne of the primary drawbacks associated with natural fiber reinforced composites is their relatively poor mechanical properties. One potential approach to overcome this challenge is to augment the fiber loading, thereby improving the interfacial characteristics and hybridization. In this study, hybrid polyester composite structures reinforced with jute/hemp fibers were fabricated via the hand layup process, with fiber loadings varying between 30%, 50%, and 70% by volume. Fibers were subjected to alkali solutions (NaOH) containing 3% and 5% alkali in advance of the composites' formation. The impact, flexural, and tensile characteristics of hybrid jute/hemp reinforced polyester composites were investigated via laboratory studies. The composite materials that underwent testing with a 50 vol% fiber loading and 3% NaOH exhibited the maximum tensile strength (26.6 MPa), tensile modulus (733.56 MPa), flexural strength (62.7 MPa), and flexural modulus (3.04 GPa).Highlights Hybrid polyester composite structures reinforced with jute/hemp fibers were fabricated. Hand layup method used with various fiber loadings (30%, 50%, and 70% by volume). Highest mechanical properties were obtained for 3% NaOH treatment and 50% fiber loading.

Experimental investigation of mechanical properties of NiTi superelastic shape memory alloy cables

As a self-centering element in a recoverable functional structure, shape memory alloys (SMAs) usually require a large diameter to provide sufficient bearing capacity, and pre-strain is applied to obtain good self-centering performance and initial stiffness. This study aims to explore the mechanical properties of large-diameter NiTi SMA cables and their potential applications in recoverable functional structures. Through the uniaxial tensile test of 11 SMA cables with 7 × 7 × 1.0 mm, the mechanical properties of SMA cables under different strain amplitudes, cyclic loading effects, loading rates, and different pre-strain modes were evaluated. The results indicate that the energy dissipation capacity of SMA cable increases with the increase of strain amplitude, but at the same time, it will reduce its self-centering capabilities. The equivalent viscous damping ratio decreases after the SMA cable enters the martensitic hardening stage. The residual strain of SMA cable depends on the combined effect of strain amplitude and number of cycles. The larger the strain amplitude and the number of cycles, the more significant the degradation of self-centering performance. After 20 times of constant amplitude loading and unloading, the mechanical properties of SMA cable are relatively stable. The reverse phase transformation stress of the pre-strained SMA cable gradually decreases with the increase of the tensile strain amplitude. The pre-strained SMA cable exhibits a stable restoring force strength in the sub-cycle, and the residual strain is zero. The test results support experimental data for applying large-diameter SMA cables in recoverable functional structures.

Experimental investigation of mechanical properties of problematic expansive soil using copper slag and its statistical validation

Experimental investigation of mechanical properties of problematic expansive soil using copper slag and its statistical validation

Experimental Investigation of Mechanical Properties of Additively Manufactured Fibre-Reinforced Composite Structures for Robotic Applications

AbstractThis study explores the variation in mechanical properties of additively manufactured composite structures for robotic applications with different infill densities and layer heights using fused deposition modelling (FDM). Glass fibre-reinforced polyamide (GFRP), and carbon fibre-reinforced polyamide (CFRP) filaments are used, and the specimens are printed with 20%, 40%, 60% and 100% infill density lattice structures for tensile and three-point bending tests. These printed samples are examined in the microscope to gain more understanding of the microstructure of the printed composites. To characterise the mechanical properties, a set of tensile and three-point bend tests are conducted on the manufactured composite samples. Test results indicate the variations in tensile strength and Young’s modulus of specimens based on the printing parameters and reveal the tensile and bending behaviour of those printed composite structures against varying infill ratios and reinforcing fibres. The experimental findings are also compared to analytical and empirical modelling approaches. Finally, based on the results, the applications of the additively manufactured structure to the robotic components are presented.

Experimental investigation of mechanical properties and morphology of bamboo-glass fiber-nanoclay reinforced epoxy hybrid composites

Experimental investigation of mechanical properties and morphology of bamboo-glass fiber-nanoclay reinforced epoxy hybrid composites

Experimental investigation of mechanical properties of PLA, ABS, and PETG 3-d printing materials using fused deposition modeling technique

Abstract In recent years, there has been a logarithmic interest in three-dimensional printing technologies. This technique has made it possible to make more intricately shaped parts of superior quality, allowing for use in a variety of industries, including aircraft, automobiles, and ships. This study characterized the materials and assessed the mechanical features of PLA, PETG, and ABS materials generated at various raster angles. The strength ratios of the various materials have been found to fluctuate when the raster angles change. The PLA parts created at a picture raster angle of 45° had the maximum tensile strength. ABS material created with a picture raster angle of 45° has been shown to have the best energy absorption, and PLA material made with a raster angle of 45° has the best performance compressive strength. When bending strength was evaluated, it was found that samples of ABS made with a raster angle of 0–90° had the greatest value. The SEM micrographs were obtained, and the tensile test was used to examine the fracture behavior of the materials. As a result, it has been found that materials created using various raster angles can have various strength values from one another.

Experimental Investigation of Mechanical Properties of Clay–Cement Slurry Containing Graphene Oxide

As a widely used material in underground engineering, clay–cement slurry grouting is known for its initial poor anti-seepage and filtration capacity, the low strength of the resulting stone body, and its tendency towards brittle failure. To explore efficient and environmentally friendly grouting materials, industrial-grade graphene oxide (GO) was incorporated into a clay–cement slurry to create a new type of slurry called a GO composite. These GO composites were then utilized to reinforce fractured formations. Uniaxial compression tests, shear strength tests, permeability tests, and electron microscopy scans were conducted to investigate the strength, permeability, and microscopic features of the GO composite-reinforced fractured formations. Furthermore, the optimization effect and application prospects of graphene oxide on clay–cement slurry materials were evaluated. The experimental results demonstrated that the modified slurry effectively improved the compressive strength (increased by 7.2% to 32.5%) and shear strength (increased by 28.6% to 105.3%) of consolidated fractured gravel. By conducting orthogonal experiments with range analysis, variance analysis, and multiple regression analysis, it was shown that there was a strong correlation between the consolidated body and three factors influencing the permeability coefficient. Among these factors, the OPC content had the most significant impact on the permeability coefficient, followed by the GO content. Graphene oxide was found to promote cement hydration reactions, guide the growth of hydration products on the surface of graphene oxide nanosheets, optimize the pore structure in grouting materials, and reduce microcracks between the slurry and the fractured gravel interface. Electron microscopy characterization and fractal analysis revealed that the addition of graphene oxide effectively reduced the degree of microdamage during the sample’s failure process. This ensured the integrity of the sample during the unstable failure process, enhanced the material’s toughness, and improved its ability to resist loads.

Experimental Investigation of Mechanical Properties on Al7075 with Hybrid Reinforcements

The study's main objective is to investigate the dry sliding wear and other mechanical properties of aluminium with newer dual particle reinforced hybrid composite compositions. The stir casting method was used to create the aluminium hybrid metal matrix composite, which was then tested to determine its hardness, wear and microscopic photographs of worn-out surfaces as a result of the wear test. Three alternative reinforcing ratios Sample 1 (1% B4C and 3% SiC), Sample 2 (1% B4C and 6% SiC), and Sample 3 (1% B4C and 9% SiC) were used to manufacture hybrid composites. In this study, samples made with three different ratios of reinforced composite material were tested for hardness and temperature wear. Results illustrated that sample 2's hardness and wear attributes (1% B4C and 6% SiC) are superior to those of the other samples in terms of both hardness and wear rate

Molecular dynamics simulation and experimental investigation of mechanical properties of calcium carbonate and graphene reinforced polylactic acid nanocomposites.

The use of Molecular Dynamics (MD) simulations to examine the mechanical characteristics of polymer compositesreinforced with calcium carbonate (CaCO3) and graphene (GR) is represented in this work. The effects of CaCO3 andGR nanoadditives in polylactic acid (PLA) matrix in different concentrations were evaluated using the results of MDsimulations. Experimental analyses have been conducted to validate the results of MD based on the mechanicalproperties of fabricated nanocomposites, including modulus of elasticity, shear modulus, and Poisson's ratio. Themodeling, computation, and analysis of several simulations on the improved mechanical characteristics ofPLA/CaCO3 and PLA/GR nanocomposites are introduced and discussed. The results revealed that the addition ofGR nanoparticles were more effective in enhancing the mechanical properties of PLA components as compared withthat of CaCO3 nanoparticles, as the modulus of elasticity, shear modulus and Poisson's ratio increased byapproximately 21%, 17%, and 16% for addition of 3 wt% GR nanoparticles in the PLA matrix, respectively. The mechanical behavior of PLA/CaCO3 and PLA/GR nanocomposites have been simulated based on the moleculardynamic technique using material studio (MS) that enabled the analyses of synergy between the polymer moleculesand the nanoparticles. Molecular models for a system of nanocomposites were built by embedding the nano-clustersinto an amorphous PLA matrix. Nanoparticles have been modeled as spherical nanoclusters of graphite and calciteunit cells. Molecular models of the pure PLA matrix were also developed for comparison. The relaxed systems of MDsimulations have been carried out to calculate the mechanical properties of nanocomposites containing 1, 3 and 5wt% nanofiller contents. To validate the results of the simulations, the PLA/CaCO3 and PLA/GR nanocompositegranules, containing different weight ratios of the nanofillers in the matrix, have been synthesized by melt-blendingtechnique. These granules have been used to produce tensile test samples by injection molding technique, withdifferent fractions of nanoparticles in the matrix, to study the effects of such nanoadditives on the mechanicalproperties of the PLA nanocomposites.

Experimental investigation of mechanical properties of bamboo/carbon fiber reinforced hybrid polymer matrix composites

Natural fiber composites are gaining popularity in various fields such as aerospace, automotive, and interior design due to their biodegradability, cost-effectiveness, and wide availability. Hybrid composites, which utilize both natural and synthetic fibers as reinforcement, are becoming more prevalent due to the desirable properties of each. Natural fibers possess strong damping properties and are biodegradable, while synthetic fibers have good elastic modulus. This research aimed to investigate the mechanical properties of bamboo and carbon fiber reinforced hybrid composites through tensile, flexural, and Izod tests. Hybrid composites exhibited 74.53% higher tensile strengths, 41.47% higher flexural strengths, and 182.24% higher impact strength than bamboo fiber reinforced composites. Carbon fiber reinforced composites had superior mechanical properties compared to hybrid and bamboo fiber reinforced composites, especially in terms of tensile and flexural characteristics. The study concludes that combining natural and synthetic fibers leads to composite materials with acceptable mechanical performance.

Numerical and experimental investigations of mechanical properties of AW 6005-T6 Aluminium alloy butt weld joint using GMAW process

This study aimed to investigate the effect of the welding heat input on the heat affected zone (HAZ) of AW 6005-T6 aluminium alloy for a butt-welded joint using gas metal arc welding. The determination of the thermal cycles, metallography, and the resulting mechanical properties in the zone makes its possible. The study involved using a welding experiment, numerical simulation, physical simulation, and mechanical tests. The welding was carried out using the pulsed gas metal arc welding (GMAW) transfer and type J thermocouples were used to develop the thermal cycles in the HAZ. Simufact® Welding was utilized for the numerical simulation. Optical microscope was used to evaluate the microstructures and Vickers microhardness test was done along the weld cross-section. The HAZ was located on the weld cross-section with a mean hardness of 63.7 HV0.1, which is considerably lower when compared with the base metal (BM) which has a hardness of 100 HV0.1. This indicates thermal softening occurred due to the heat input to the material. There is a match in the hardness values of the Gleeble samples and the locations on the weld cross section suggested by the model showing validity of the simulation. It is important to note the fact that there is an influence of heat input into aluminum AW 6005-T6 weld joints and its mechanical properties in the design of welding process parameters for automotive parts. The welding parameters can be optimized to decrease the heat input into the weld, as this can directly affects the mechanical properties in the HAZ.

Experimental investigation of mechanical properties of Palm - Bamboo – Glass fibre composites

Experimental investigation of mechanical properties of Palm - Bamboo – Glass fibre composites