Hydraulic Universal Testing Machine Research Articles

The effect of the modification mechanism of SiO2 in resin‐based friction materials on the mechanical and tribological performance

AbstractThis study aimed to address the thermal degradation of resin‐based friction materials in the mid‐temperature stage (200–250°C), as well as the resulting instability of the friction coefficient and decrease in the mechanical properties. To investigate the impact on the toughening and wear resistance properties, this study employed nanosilica‐modified resin‐based friction materials. The mechanical, friction, and wear properties of the modified samples were tested using a Rockwell hardness tester, hydraulic universal testing machine, and constant speed friction tester. The phase composition and microstructure of the samples were analyzed by scanning electron microscope, energy‐dispersive x‐ray spectroscopy, x‐ray diffraction. When the mass fraction of nanosilica was 3%, modified sample S3 exhibited excellent mechanical properties, with shear strength and compressive strength reaching 40.3 and 171.7 MPa, respectively, which were increased by 30% and 9% compared to unmodified sample S1. Moreover, the density and hardness of sample S3 showed minimal variation compared to those of unmodified sample S1. In the temperature range of 100–250°C, the wear rate of modified sample S3 remained within the range of 0.22 × 10−7–0.38 × 10−7 N−1 m−1, with a friction coefficient of 0.38 at 200°C, demonstrating excellent wear resistance.

Impact of infill density on morphology and mechanical properties of 3D printed ABS/CF-ABS composites using design of experiments

Metal Extrusion (MEX) is a leading 3D printing technology for polymers, enabling intricate designs and personalized products in various applications. The current study evaluate how infill density affects the tensile, flexural, compressive, Izod impact and fracture behaviour of Acrylonitrile Butadiene Styrene (ABS) and Carbon Fiber Reinforced-Acrylonitrile Butadiene Styrene (CF-ABS) specimens manufactured using the MEX method. Different infill densities of 20, 40, 60 and 80 % are used in the production of honeycomb infill pattern samples for investigating the mechanical as well as fracture behaviour of MEX ABS/CF-ABS components. The experimental runs of fabricated composites were tested using a digital Izod impact tester and servo-controlled hydraulic universal testing machine, following ASTM standard procedures. The experimental findings show that CF-ABS specimens with an 80 % infill density and honeycomb fill pattern showed significant improvements in tensile strength, modulus, yield strength and elongation. The flexural strength (64.74 %), flexural modulus (209.15 %), compressive strength (125.21 %), compressive modulus (108.34 %) and impact strength (38.91 %) of these specimens are comparable to those of 3D printed ABS specimens and other infill densities. The research shows that precise management of processing variables can greatly improve the mechanical properties of 3D-printed ABS samples, providing valuable insights for a range of applications.

The Effect of Welding Current on Shear Test and Microstructure TIG Brazing of Cemented Carbide and Steel

The need for good welding results as knowledge in the process of welding different types of materials is needed in the community, and this res- earch is to determine the effect of variations in welding currents of different types of metals on cemented carbide and carbon steel using the TIG brazing method. For the base metal, YG6 cemented carbide and SS400 carbon steel with CuSi filler metal are used. The sample method is made by connecting different types of materials with the welding process using variations in current of 60 ampere; 80 ampere, and 100 ampere. The mechanical properties of this material connection were tested using the Hydraulic Universal Testing Machine, while for the microstructure examination, a microstructure test tool with a magnification of 100 x was used. The results of the tests revealed that the highest average compressive strength was 22.2 kN at a welding current variation of 60 A, and the lowest average value was 10.2 kN at a welding current variation of 100 A. Furthermore, for the average value of shear stress, the highest value at 60 A variation is 148 N/mm2 and the lowes t value is at 100 A welding current, which is 67 N/mm2. The res ults of testing the microstructure of the connection area s how that the higher the current strength, the more enriched the Cu content and will affect the size and spacing of Si grains.

Investigating dynamic compressive strength of concrete by using high-rate hydraulic universal testing machine

This study proposes using a new high-rate hydraulic universal testing machine (HR-UTM) to measure the compressive strength of concrete at high strain rates. The HR-UTM eliminated the necessity of friction between the specimen and support. Furthermore, the strain history could be directly measured using strain gauges attached to the specimen. The compressive stress versus strain response of concrete was successfully measured at high strain rates until 19.3 s−1. The proper aspect ratio of the cylinder specimen (D75 ×L150 mm) 2.0 and amounts of lubricants more than 11.3 mg/cm2 could minimize the effects of end friction on the concrete compressive strength.

Effect of Heat Treatment on the Vibration Isolation Performance of Axially Symmetric NiTi Wire Mesh Damper

In this paper, superelastic (SE) NiTi wire is used to fabricate axially symmetric wire mesh dampers (WMDs) with the expectation of a higher damping capacity. However, the phase transformation damping of the NiTi WMD could be suppressed by the cold-work-induced dislocation. Therefore, the NiTi WMDs were heat-treated and then tested by a hydraulic universal testing machine. The NiTi WMD is found to achieve higher damping capacity when heat-treated at 200 °C. However, the WMD heat-treated at 250 °C suffers from a sharp decline in the loss factor in exchange for an improvement in the stiffness. The sine sweep test was then conducted to examine the dependency of the WMD’s vibration isolation performance upon the heat treatment temperature and the excitation acceleration. The NiTi WMD outperforms the 304 stainless steel (SS 304) WMD in damping capacity only when the excitation acceleration magnitude is less than 1.5 g. The stiffness of NiTi WMD can be improved without significantly compromising its damping capacity by heat treatment at 200 °C for 30 min. The present work carries out comprehensive measurements of the NiTi WMD’s response to dynamic mechanical test and sine sweep test and addresses how heat treatment influences the stiffness and damping capacity of the SE NiTi WMD.

Tensile Strength and Micro-Hardness Properties of Common Roofing Sheets in Ghana.

Background: The request for housing in Ghana is great and as a result the selection of durable roofing sheets have become very significant as roofing plays a vital role in building construction. This study examines some mechanical properties of the most common locally-produced and imported roofing sheets in the housing industry in Ghana to inform decision-making when it comes to roofing. The roofing sheets chosen were One Star Galvanized Japan (G1*Jap), Galvanized Coated (GC), Aluzinc three star galvanized (AlZn3*), One Star Galvanized Indi (G1*Ind) and Aluminium (Al) due to their popularity and wide availability on the market. Samples from these were cut into specific dimensions and placed in a Tinius hydraulic Universal Testing Machine (Model 602) for testing. Results: The results showed that AlZn3* had the highest Young’s Modulus of Elasticity of 18.21MPa, Ultimate Tensile Strength (UTS) of 50.27 MPa; Aluminium (Al) recorded the highest Percentage Elongation of 28% and Breaking Energy 7956600 MJm-2 with G1*Jap recording the least UTS of 26.6 MPa and Breaking energy of 55378 MJm-2 whiles G1*Ind showed the least Young’s Modulus of Elasticity of 7.6 MPa and Percentage Elongation of less than one percent (0.5%). Conclusion: These numbers lead to the conclusion that AlZn3* roofing sheet is generally the best roofing sheet. Based on this it was concluded that AlZn3* is the best roofing sheet on the Ghanaian market due to its unmatched mechanical strength.

Hybridization effect on water absorption and flexural properties of E-glass/banana fibre/epoxy composites

Hybrid composites occupying the area of standard materials by satisfying the necessities of various sectors like part industries, automobile industries, ship building and numerous bio-medical sectors. the most reason to substitute standard materials is that the hybrid composites giving same or additional needed properties with less weight and value than standard materials and most output in minimal consumption with higher lifespan to seek out the economical suggests that of utilizing the technology for various applications. Mats were fancied and stratified up with rosin matrix. The laminate is factory-made exploitation hand lay-up technique followed by compression moulding. Critical properties of the fancied material like flexure, enduringness, square measure through an experiment all over and results square measure recorded. The aim of the current analysis work was experimental investigation to judge numerous mechanical properties of hybrid fiber compound composite (E-glass fiber and epoxy, Banana fibres) at totally different weight percentages with epoxy. The properties of E-glass fiber and epoxy, Banana, fibres were found to be sensible large to be used as reinforcement in composite materials. The results of the experiments were per shaped on one hundred kN servo hydraulic universal testing machine (UTM) (50% E-glass, 100% of banana fiber and therefore the four-hundredth of epoxy resin) will study associate optimum results of the composite. In water absorption take a look at C-1(20% E-glass, four-hundredth of banana fiber and therefore the four-hundredth of epoxy resin) will observe the absorption of water. and at last experimental study the water absorption depends on amount of banana fiber.

Effect of Doped Glass Fibers on Tensile and Shear Strengths and Microstructure of the Modified Shotcrete Material: An Experimental Study and a Simplified 2D Model

Shotcrete material has found extensive applications as a reinforcing material in the engineering sector. This study examined the effect of doped glass fibers on the mechanical performance of the modified shotcrete material composed of aeolian sand, fly ash, cement, quicklime, and doped glass fibers. Its tensile and shear strengths values were experimentally determined via a WAW-1000D computerized hydraulic universal tensile testing machine. Its microstructure was analyzed via a size analyzer, scanning electron microscope (SEM), and X-ray diffractometer (XRD). A 2D simplified mechanical model was elaborated to reflect the influence mechanism of the doped glass fibers on the mechanical performance of the modified shotcrete material. The experimental and mechanical analysis results indicated that, at the macroscopic scale, the experimental tensile and shear strengths of the shotcrete material doped with glass fibers were significantly higher than those of the undoped shotcrete material (by up to 310% and 596%, respectively). These results were in concert with the proposed model predictions, where the compound stresses in the shotcrete material were derived as the sum of the stress borne by the shotcrete material itself and the bridging stress exerted by the glass fibers. At the microscopic scale, SEM observations also revealed that the glass fibers were intertwined with each other and tightly enveloped by the shotcrete material particles within the modified shotcrete specimens, connecting the particles of different components into a whole and improving the overall mechanical strength. In addition, the relationships of the compound stress of the shotcrete material vs. embedment length, embedment angle, and cross-sectional area of the glass fibers were established. The research findings are considered instrumental in clarifying the mechanism by which the glass fibers influence the mechanical performance of shotcrete materials and optimize their solid waste (fly ash and quicklime) utilization.

Effect of adding carbon nanotubes into the matrix material on the buckling behavior of glass/epoxy composite plates: An experimental study

In this research, buckling of polymer matrix composite plates containing unidirectional glass fibers under in-plane pressure load is investigated. Moreover, the effect of adding carbon nanotubes as reinforcement into the matrix material on the critical buckling load of composite plates is studied. Using hand lay-up method, rectangular glass/epoxy composite plates with and without carbon nanotubes were fabricated. 0.25, 0.5 and 1.0 weight percent of carbon nanotubes were added to the epoxy resin and composite plates were subjected to the longitudinal in-plane pressure load. The plates were tested under fix ended boundary conditions utilizing Instron hydraulic universal testing machine. Based on the results, adding 0.5 weight percent of carbon nanotubes has the most influence on the critical buckling load of the plates. Results show that adding 0.5 weight percent of carbon nanotubes into the matrix material increases the critical buckling load of the carbon nanotubes /glass/epoxy plate more than two times with respect to that of glass/epoxy composite plate. Furthermore, when the carbon nanotubes weight percent reaches 1 %, because of carbon nanotubes agglomeration, carbon nanotubes are not dispersed well into the epoxy resin and the critical buckling load of the composite plate decreases. To validate the results, buckling analysis of glass/epoxy composite plate was done in Abaqus finite element software. Finite element models confirm the experimental results obtained.

Combining Thermal Loading System with Acoustic Emission Technology to Acquire the Complete Stress-Deformation Response of Plain Concrete in Direct Tension.

The tensile properties of plain concrete are very important for the concrete structural design, and the complete tensile stress-strain curve is essential for creating accurate and reliable designs, especially when considering special load cases such as earthquakes and impacts. To study the complete tensile stress-deformation response of plain concrete, the direct tension tests were conducted on a novel thermal tensile testing machine (TTTM), which was reformed from a hydraulic universal testing machine (UTM). Acoustic emission (AE) technology was applied to monitor the damage process of plain concrete in tests. The TTTM was powered by the thermal expansion of loading columns, and had a stiffness similar to the specimen, thus eliminating the potential AE noises in the UTM, and simulating the rapid fracture process in real concrete structures. A static-dynamic acquisition system was established to obtain the complete tensile stress-strain curves, of which the data before and at the fracture moment were respectively acquired by the static acquisition system and the dynamic acquisition system. The AE technology is a useful approach to analyze the damage process of concrete, and makes it feasible to determine the damage state and the fracture location of the specimen in real time.

Evaluation of mode III Delamination behaviour of modified Carbon/Glass Fibre Reinforced Polymer Composites with Nanoclay particles

Incorporating nanofillers in epoxy resin is a novel approach to improve the mechanical properties of polymer composites. Recent studies discloses that the inclusion of nanofillers such as SiC, CNT, alumina and nanoclay into epoxies at micro and nanoscale levels enhances the mechanical properties of epoxies. In this research, the improved mechanical properties of nanoclay modified carbon/glass fibre-reinforced polymer nanocomposite (FRPNC) were investigated. The neat DGEBA epoxy resin was modified with nanoclay at different wt % (0.5- 2wt %) by ultrasonication process for achieving better dispersion of nanofillers. The modified polymer laminates were fabricated with unidirectional carbon/glass fibres with the stacking sequences of (0°G/0°G/0°C)S using hand lay-up process. The mechanical properties such as mode III delamination toughness, tensile strength and flexural strength were investigated using servo controlled hydraulic universal testing machine and 3-point bending test setup respectively. The highly cross linked structure between epoxy and nanoclay particles improves the mode III fracture toughness, tensile and flexural properties. The damage mechanisms of fractured specimens are characterised by SEM images.

Identification of the anisotropic plasticity using the virtual fields method for 2024 aluminium alloy

In this work, the virtual fields method was applied to identify the anisotropic plastic constitutive parameters for the wrought 2024 aluminium alloy. First, low cyclic tension-compression tests were conducted for the specifically designed aluminium alloy specimens on a hydraulic universal testing machine and the full-field deformations measured by digital image correlation. Then, the measured experimental data were used to simultaneously identify the constitutive parameters of the Hill 1948 yield criterion and the nonlinear kinematic hardening model based on the virtual fields method. Reasonable identified parameters were obtained. The fitting curves of the virtual work during the minimization process verify the reliability of the identification results.

Devulcanization of natural rubber industry waste in supercritical carbon dioxide combined with diphenyl disulfide

The elimination of rubber wastes without affecting the environment is one of the most important challenges of the 21st century waste management. Accordingly, the present work is focused on the recycling of natural rubber (NR) industry waste by means of devulcanization in supercritical carbon dioxide (scCO2) atmosphere. With that aim, a novel device allowing to perform rubber devulcanization was developed. It consists of a triaxial compression reactor integrated into a dynamic hydraulic universal testing machine with a heating chamber. NR industry waste was devulcanized in the mentioned device at different temperatures, in scCO2 by using diphenyl disulfide (DD) as devulcanizing reagent. The devulcanization degree and quality of the treated materials were evaluated by the swelling test combined with the Horikx theory. It was appeared that a successful devulcanization, with almost no degradation, was obtained, and the devulcanization degree reached maximum value of ~90%. Thermogravimetric tests and scanning electron microscopy (SEM) images strengthened these results. Finally, it was concluded that the developed device is appropriate to perform rubber recycling, which contributes to the progress in the environmental protection.

Novel composite connection for timber–glass composite structures

This study presents a newly developed timber–glass point connection intended to strengthen existing timber elements in a reversible and visually unobtrusive manner. The new connection consists of an aluminium insertion, two-component structural bonding epoxy resin adhesive, and self-tapping screws. The connection offers the possibility of easy attachment and detachment of the glass element from the strengthened timber element. Seven timber–glass specimens were constructed to perform an experimental investigation of the shear load-bearing capacity and load-slip behaviour of the connection. The aluminium insertion is bonded to a tempered glass strip with a hole and is screwed to the spruce timber block. The timber–glass connection preparation process is thoroughly presented. A special testing apparatus was developed to perform the experiments on a hydraulic universal testing machine. The experimental results are evaluated using analytical expressions and a finite-element simulation. The average connection load-bearing capacity obtained from the experiments of the analysed specimen was 13.31 kN, and the average slip modulus was 20.48 kN/mm. All connections failed on account of self-tapping screw failure, whereas the tempered glass strips remained undamaged.

Preparation and properties of silicate inorganic exterior wall insulation based on thermal energy storage

The key to building energy conservation is how to make the exterior wall have good thermal insulation performance, reduce the heat loss of the building?s peripheral structure, develop new exterior wall insulation materials, and effectively achieve energy saving. In this paper, a new type of composite silicate insulation material was prepared by using fly ash, sepiolite fiber, basalt fiber, and cement as raw materials. According to the analysis of the action of each component of the composite silicate thermal insulation material, the composite silicate thermal insulation material is prepared by selecting different raw material ratios, and the fly ash and sepiolite fibers are analyzed by a thermal conductivity measuring instrument and a hydraulic universal testing machine. The influence of water-cement ratio on the thermal conductivity, tensile strength, and compressive strength of composite silicate insulation materials. Through research, it is found that this composite silicate exterior wall insulation material utilizes some abandoned resources to help the building exterior wall to store thermal energy. The preparation process is simple, the insulation performance is good, the mechanical strength is high, and there is great promotion value and application prospect.

Effect of recoating slurry with different particle size on the properties of reticulated porous mullite ceramics

Mullite reticulated porous ceramics (RPCs) were fabricated with fly ash, alumina, and andalusite by polymer sponge replica technique, followed by the process of vacuum infiltration with recoating slurry included. And the effect of different recoating slurry with different particle size fly ash on the properties of mullite RPCs was studied. The matrix slurry and recoating slurry were investigated and optimized. And then, the microstructure, composition of phases, and mechanical properties of mullite RPCs were examined by SEM (scanning electron micrograph), XRD (X-ray diffraction), and hydraulic universal testing machine. Moreover, the influence of particle size of fly ash on the thermal shock stability was analyzed by calculating residual stress model and grey relational model. The result indicated that the specimens that were recoated by the slurry with the smaller particle size of fly ash might have more excellent properties.

Mechanical response and crack propagation of oil well cement under dynamic and static loads

The dynamic mechanical properties and fracture mechanism of three types of oil well cement with different formulations were investigated using a Φ50 mm split Hopkinson pressure bar (SHPB) and quasi-static mechanical tests were conducted with a hydraulic universal testing machine. The stress-strain diagram, time-stress diagram, total energy absorption diagram, and the dynamic growth factor (DIF) under different strain rates were obtained. The crack propagation process of the oil well cement under dynamic loading is evaluated using high-speed photography to determine the fracture mechanism. The test results show that the strength of the cement increases under a dynamic impact. The compressive strength of the pure cement increases from 37 MPa to 184.80 MPa under static loading. However, the peak stress of the cement stone strengthened with cellulose fiber is lower under a dynamic load than a static load. Under dynamic loading, the absorption energy is higher for the pure cement stone than for the cement stone reinforced with whiskers and cellulose. Furthermore, the crack initiation, crack propagation, and fracture characteristics of the oil well cement are different under dynamic and static loads. Under a static load, the rupture of the cement is the result of the propagation of the tensile cracks. Under dynamic loading, there are fewer micro cracks on the cement surface and a composite fracture results from tensile and shear cracks.

Experimental Investigation on Forming Limit Diagram of Mild Carbon Steel Sheet

The sheet metal forming process is the process of deforming the sheet metal into a desired shape without fracture or excessive localized necking. Variables in sheet metal forming process can be discussed together with formability and test methods. There are many defects occurring during sheet metal forming processes, such as cracking, wrinkling, local necking, buckling etc. The strain measurement in a deformed sheet metal is necessary for measurement comparison. As the thickness of sheet metal is very small as compare to other dimensions of the sheet metal, the sheet metal operation is usually considered as a plane stress problem. The Forming Limit Diagram (FLD) was also determined from surface strain measurement. The FLD is the graph between major strain (℮1) and minor strain (℮2). The Forming Limit Curve (FLC) or the Forming Limit Diagram (FLD) is useful concept for characterizing the formability of sheet metal, which reflects the maximum principal strains that can be sustained by sheet materials prior to the onset of localized necking. Generally there are three methods to establish FLD i.e. theoretical, numerical and experimental. In this paper experimental method is used to develop FLD. For experimental determination of FLD of Mild Carbon steel sheet Limit Dome Height testing is used according to the American Society of Testing Material (ASTM) as published in ASTM E 2218-02. In this paper the procedure of grid marking, punch stretching and strain measurement is used. For punch stretching operation the set up of spherical die and punch has developed on the hydraulic Universal Testing Machine (UTM). The material used for the die and punch is High Carbon High Chromium Steel (HCHCr). For printing the grids on sheet material chemical etching method is used. In this grid making process grids of 5 mm diameter circles printed. For trial experiment the sheet metal sample is stretched at the force of 23 KN. The deformed circles were converted into ellipse and from that deformed ellipse major and minor strains are to be calculated. After that the FLD will give the two different regions of safe and failure zone.

Experimental characterization of dynamic deformation behaviour for SCM440 steel at high strain rates

The dynamic deformation behaviours of SCM 440 steel were characterized at the strain rates from 10-3 s-1 to 106 s-1. The uniaxial tensile tests at different temperature of 25 °C, 350 °C, and 700 °C were performed by a hydraulic universal testing machine equipped with a heating stage, and the compressive tests were conducted by using a spilt Hopkinson pressure bar (SHPB) at room temperature. Material coefficients of the Johnson-Cook constitutive model considering temperature effects were obtained based on the stressstrain relations from the experimental tests. In addition, Taylor impact tests on the SCM 440 steel were carried out to evaluate the accuracy of the determined material coefficients and characterize the dynamic behavior at the ultra-high strain rates and high temperature, by comparison with numerical simulations.

Effect of cryogenic treatment on microstructure and properties of acrylonitrile–butadiene–styrene

In order to improve the mechanical behavior of polymer materials for three-dimensional printing. acrylonitrile–butadiene–styrene (ABS) samples are divided into five groups, based on different degrees of cryogenic treatment. A hydraulic universal testing machine is used to test the samples’ tensile properties, percent elongation and bending strength, while each sample’s wear performance is tested by using a tribometer. In addition, the functional groups and the internal molecular chain in every sample are characterized by Fourier transform infrared spectroscopy. The experimental results show that cryogenic treatment is an effective technique for the enhancement of the mechanical properties of ABS, such as its tensile strength, bending strength, wear performance and crystallinity. Particularly, the mechanical properties of ABS are improved after cryogenic treatment at −130°C for 4 h. The tensile strength is improved by 6·31 MPa, 93% higher than that of unprocessed samples. The bending strength is improved by 2·46 MPa, and the wear performance significantly exceeds that of the other groups.