Preparation Of Test Specimens Research Articles

Edge detection in x-ray images of drill mast welds based on an improved Scharr operator

Rotary drilling rigs are extensively used in foundational construction, with main components including the mast, drill rods, drill bits, power head, and cockpit. The mast, a critical component, must be of high quality to ensure operational reliability. To ensure the reliability of the mast during operation, it is necessary to detect defects in the most stress-prone areas. Based on finite element analysis and practical engineering experience, the welds on the large circular disc of the drill mast are identified as the most vulnerable to damage. Accordingly, this paper prepared test specimens specifically from these weld locations and conducted X-ray inspections, obtaining images for analysis. Given the inevitable presence of noise due to objective conditions, the images first underwent median filtering. For effective subsequent defect detection, edge detection was performed on the images. Among various edge detection operators, the Scharr operator was found to be highly effective. To further enhance the edge detection performance, this paper introduces an improved Scharr edge detection algorithm that incorporates dynamic thresholds and Markov Random Field (MRF) techniques. The enhanced algorithm was evaluated using signal-to-noise ratio and edge localization accuracy as metrics, and it was found to significantly improve performance.

Itaconic acid-based 3D printed nanocomposites: An in-depth study on the effect of nanoinclusions on the physicochemical properties and the printability of formulations based on polyester itaconates

The demand for novel bio-based materials in UV-curing additive manufacturing has surged due to increasing environmental concerns and a growing emphasis on sustainable practices in the manufacturing industry. However, at the moment, their thermomechanical performance is not equal to that of their fossil-based counterparts and this impedes the acceptance of these materials within the industrial community. Therefore, in this study, a series of nanocomposite polyesters based on itaconic acid was synthesized for the first time with in-situ polymerization, in an attempt to leverage the unique properties of nanofillers and improve the overall performance of the material. A variety of reinforcing agents were utilized, namely cellulose nanocrystals (CNC), montmorillonite (MMT), graphene nanoplatelets (GNP) and titanium dioxide (TiO2), to understand the effect of each filler on the physicochemical properties of the polyester. Formulations of these polyesters were then prepared and processed on a digital light processing (DLP) 3D printer to prepare test specimens. Extensive thermomechanical characterization showed that the interference of the fillers with the UV curing process was the main parameter determining the mechanical performance of the 3D printed materials.

Effect of alumina fillers on physical and mechanical properties of luffa/groundnut shell natural fiber reinforced polymer composites

AbstractThis study aims to investigate the physical and mechanical properties of epoxy composites reinforced with hybrid luffa waste and groundnut shell waste natural fibers and to evaluate the effect of different filler loadings of alumina on the mechanical behavior of the hybrid composites. The luffa fibers were made to undergo mercerization in 10% NaOH solution. All the treated fibers and the alumina fillers were characterized using X‐ray diffraction analysis (XRD). The study used three different filler loadings of alumina (Al2O3) (5%, 10%, and 15% by volume) and three different fractions of treated luffa‐waste groundnut shell hybrid fibers (10%, 30%, and 50% by volume). The composites were fabricated using the hand layup technique, and the prepared test specimens were subjected to mechanical and physical properties testing as per ASTM standards. The experimental findings indicated that the inclusion of Al2O3 filler improved the physical and mechanical characteristics of the natural fiber‐reinforced hybrid composites. The results showed that the composites with 30 vol. % fibers (1:1 luffa fiber: groundnut shell fiber) and 10 vol. % Al2O3 content showed enhanced tensile, flexural, shear, and impact strength and hardness. Besides, a good synergy between the alumina fillers, natural fibers, and the polymer matrix was observed in the surface morphology of the composite specimen. The developed composites can be used in low and medium‐load‐bearing structural and non‐structural applications.Highlights Development of hybrid polymer composites with luffa and novel groundnut shell fibers Hybridization of alumina ceramic particles with natural fiber hybrid composites Assessment of physical and mechanical properties of the polymer composites

Automated Composite Pipe Cutting Machine for ASTM Standard Testing Specimen Preparation

This thesis aims to design a pipe-cutting machine using costume-made metal fixtures, an Avid CNC Bentch Top machine, and Mach4 control software to cut strips off from pipes made of PVC, resin, and fibreglass materials automatically. The costume-made fixtures clamp down the pipe and rotate it to perform multiple cuts around it. Avid CNC Bentch Top Machine is used to perform the ramping cut with a 10mm diameter square shoulder milling cutter. A touch probe is mounted beside the cutter to measure the accurate pipe diameter. An HMI (Human Machine Interface) that allows the operator to input the dimension of the pipe and perform calibration before use is developed using the LUA language under Mach4 motion control software. Screen and button scripts are programmed to read the input from the operator and sensors to generate a Gcode file to drive the CNC machine. The machine prototype can cut 5 strips in 30 minutes with the dimensions and surface finish required by ASTM D790 and ASTM D638, significantly increasing the production rate and reducing the waste of human resources while focusing on the environmentally friendly and cost-friendly for small businesses.

Enhancing S45C steel for the primary component of an automatic coupler using quench-tempering techniques

Coupling links and hooked plates constitute the primary components of automatic couplers in trains, enduring substantial tensile and compressive loads during train connections. This study endeavours to enhance the strength of S45C material through heat treatment techniques. The research commenced with the preparation of JIS S45C tensile test specimens adhering to ASTM E8 standards. The material's chemical composition was validated using an Optical Emission Spectrometer (OES). Six heat treatment variations were employed, including quench oil without tempering (QO), quenching water without tempering (QW), quenching oil tempered at 660°C (QOT660), quenching water tempered at 660°C (QWT660), quenching oil tempered at 550°C (QOT550), quenching water tempered at 550°C (QWT550), alongside untreated conditions (NT) for comparison. The efficacy of heat treatment was evaluated through tensile testing, optical metallographic analysis, and micro-Vickers hardness tests. QO and QW scenarios were excluded from the tensile tests. Results revealed that QWT550 demonstrated the most substantial enhancement in material yield, exhibiting a 115% increase. Moreover, hardness testing indicated superior hardness in QWT550 specimens compared to other tempered variants. The metallographic analysis illustrated the formation of identical and smooth martensitic structures. Overall, the combination of cooling heat treatment and tempering proved sufficient to meet the design requirements of hooked plates and coupling links for automatic couplers.

The needle penetration index for estimating the physico-mechanical properties of pyroclastic rocks

Preparation of suitable core specimens for physico-mechanical testing s not always possible, particularly for soft and clay-bearing rocks. Although several indirect test methods have been proposed to predict the properties of rocks, specimen preparation from soft rocks for some indirect tests is still difficult. For such cases, the needle penetration test has been developed. In this paper we present a study on the predictability of the physico-mechanical properties of pyroclastic rocks from the needle penetration index (NPI). The NPI, uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), density, and porosity tests were performed in the laboratory on specimens from ten different locations in Turkey. Correlations were established between the NPI values and the physico-mechanical properties. Strong correlations were observed between NPI and both UCS and BTS. General correlations were found between NPI and both density and porosity.

Performance evaluation of WMA mixtures with RAP

Nowadays, asphalt industries are seeking for new methodologies in order to minimize global warming and emission of greenhouse gases. One of the solutions found out was the use of warm mix asphalt (WMA) technology which allows reduction in asphalt mixing, working and compaction temperature. WMA reduces the desired temperature in comparison with hot mix asphalt by 20–40°C. In addition to this issue, the lack of superior quality natural aggregate resources everywhere around the world, it is essential to use the available natural resources efficiently along with the available construction and demolition waste such as recycled asphalt pavement (RAP) if possible, without compromising in the performance of the mixtures. In this study, reclaimed asphalt pavement was used as partial replacement for conventional aggregates and binder. The RAP contents of 0%, 25% and 50% were considered. Zycotherm was used as warm mix additive which improves the pavement moisture resistance by serving as an anti-stripping agent. The mixtures were prepared with HMA @ 130°C, HMA @ 160°C, WMA @ 130°C and all these three mixtures with partial replacement with RAP. The RAP material with 0, 25 and 50% replacement was adopted for both HMA and WMA for DBM grade 2 course. Zycotherm was added by 0.1% by weight of binder in both HMA and WMA mixes. The prepared test specimens were tested for Marshall and indirect tensile strength (ITS) test. The test results indicated that the WMA blend prepared using 0.1% by the weight of binder content showed good results compared to the hot mix asphalt @ 130°C. The indirect tensile strength ratio (TSR) of mixes containing RAP is found to be higher when compared to the mixes without RAP indicating lower moisture susceptibility of the mixtures. This study demonstrated the possible use of RAP in WMA mixes with better performance than HMA.

Fatigue Strength of Rotary Bending Copper Materials

Non-ferrous metal is a type of metal that does not contain iron (Fe). Pure non-ferrous metals do not need alloying elements because of their chemical resistance and good electrical conductivity. The non-ferrous metal in question is copper. Almost every human need can’t be separated from the element of copper as a supporting material. In the industrial world, copper has an important role because many factory machinery construction utilizes this material. Copper is a material that conducts heat and electricity quite well and has smooth and soft properties. The durability of copper-based structures can be carried out by fatigue tests (fatigue). This study aims to analyze the fatigue strength of copper material with rotary bending type. The test was carried out on copper material without heat treatment. At each loading, the test was carried out five times on different test specimens (Sp1, Sp2, Sp3, Sp4, and Sp5) with variations in the load determined at 15 kg, 17 kg, and 19 kg. Preparation of test specimens using a lathe and photos of micro and macro structures using a microscope. While the fatigue test was carried out using a rotary bending type fatigue test machine. The results of microstructure observations for all loadings showed that the specimens had soft properties. Meanwhile, the observation of the macro structure shows that the specimen has brittle properties. The results of the fatigue test show that the flexural stresses for each load of 15 kg, 17, kg, and 19 kg are written as 33 kg/mm2, 37 kg/mm2, and 42 kg/mm2, respectively.

Investigating the effects of SiC particles addition and thermal treatment on 90% Al- 10% Cu alloy

Investigation of the effects of SiC particles addition and thermal treatment on 90Al-10Cu alloy has been undertaken. The work produced 90Al-10Cu Alloy and further produced test castings to which particle additions of SiC were added in the order 0.5%SiC, 1%SiC, 2%SiC and 4%SiC to see the effects of a wider variation in particle addition. These additions were made using stir-cast method to produce the test sample bars. The test sample bars were then taken to the University of Uyo, Faculty of Engineering workshop to prepare the test specimens into standard specifications for various tests. Some of the prepared test specimens were then given thermal treatment called age hardening. The specimens were first solutionised in the furnace at 500 oC (500 C) and quenched in warm water at 60C. It was then aged at 170C for three hours before cooling in air. It was after this treatment that the test specimens were subjected to hardness test, wear resistance test, strength test, and microstructure analysis. The result of the work showed that the thermal treatment had effect on the microstructure of all the samples. The result also showed that the SiC particle addition also affected the mechanical properties of the specimens. For the untreated compositions the alloy and 90Al-10Cu/2%SiC particulate composite had the lowest wear rate value of 0.0212mm3/N/m. 90Al-10Cu/1% SiC had the highest hardness value of 67.38 BHN. 90Al-10Cu/0.5%SiC particulate composite outperformed other compositions with the following mechanical properties: hardness value of 64.28BHN; ultimate compression strength of 217.18N/mm2; % reduction at failure of 3.01; and wear rate value of 0.0633 mm3/N/m. For the thermally treated compositions; the lowest wear rate of 0.0246mm3/N/m is with the alloy composition and 90Al-10Cu/2%SiC particulate composite. 90Al-10Cu/1%SiC particulate composite has the highest hardness value of 82.02BHN; the highest % reduction at failure of 1.13%, and wear rate value of 0.05982, while 90Al-10Cu/0.5%SiC particulate composite has hardness value of 80.12BHN, ultimate compression strength of 240.95N/mm2, % reduction at failure of 1.06%, and wear rate of 0.0895mm3/N/m. The 1% SiC reinforced particulate composite performed better than other compositions, but it is closely followed by 0.5%SiC reinforced particulate composite for the thermal treated compositions in terms of improved mechanical properties. This correlates with their microstructures which all show the precipitation of a second phase.

Microstructural analysis of some reinforcement steel rods used for concrete reinforcement and their effect on the mechanical properties, and carbon equivalent values of the reinforcement steel rods

The microstructural analysis of some reinforcement steel rods used for concrete reinforcement and their effect on the mechanical properties, and carbon equivalent values of the reinforcement steel rods have been studied. The work subjected the samples to test specimen preparation as required by standard specification for each test. Samples from five different mini mills were investigated for hardness, impact strength, composition, and microstructure. The result obtain from the work, has clearly shown that the microstructure of all the samples investigated reflected the hardness, impact strength, and the CEV of the samples. The microstructure of sample D with spheroidal pearlite dark areas, and a ferrite matrix had the highest hardness value of 34.61BHN, impact strength of 274.7J and CEV of 0.545. These values correlate with the microstructure. The work showed that as the CEV is increased the hardness and the impact strength of the material also increased. The work also show that as the total carbon (TC) % in the samples increased the microstructure becomes darker and the hardness and the impact strength also increased. In conclusion the microstructure of the reinforcement steel rods had effect on the hardness, impact strength properties, and carbon equivalent value of the reinforcement steel rods.

Optimal Design of Orthogonal Test for Resistance Spot Welding

The optimal parameters of the resistance spot welding process are discussed, combined with the development and practice of the automobile manufacturing industry. The value, significance, and basic theory of the resistance spot welding process orthogonal test are summarized, and the importance of the orthogonal test is recognized. Then summarize the orthogonal test specimen and equipment preparation, test design, and finally analyze the orthogonal test to conclude that the optimal parameters of the resistance spot welding process are optimized, that is, the welding time is 9cyc, the electrode pressure is 1600N, and the optimal welding current is It is 11.5kA, which provides a reference for future manufacturing.

Tribological Behaviour of Enamel Coatings Created by a Prototype Device for Local Repair of Inorganic Surfaces.

The ability of materials to withstand environmental influences is a frequent necessity in many industries. Special requirements are imposed by such industries where surfaces are affected by acidity during the processing or storage of products. In such cases, when the basic surface is exposed to chemical influences, it is possible to use enamel coatings, which, with their properties, guarantee the protection of the surface and achieve the required service life of the material. This article deals mainly with the interaction between the base material and the enamel and its resistance to wear between the original and the renovated surface caused by local heating. The article presents a methodical procedure for the preparation of test specimens with an enamel layer prepared by AWJ cutting, eliminating its damage. There are minimal differences in the microstructure between the original and the renovated surface due to the production technique. The renovated enamel surface had more bubbles of a larger size than the original surface. Good adhesion between the base metal material (substrate) and the ground coat was demonstrated. The tested surfaces demonstrated high resistance to intensive abrasion conditions with low linear wear increments.

Robotically automated 3D printing and testing of thermoplastic material specimens

An automated platform to explore parameters for pellet-based 3D printing and characterize the samples for weight, impact strength and surface quality.

Dry sliding wear and microstructural behavior of stir-cast Al6061-based composite reinforced with cerium oxide and graphene nanoplatelets

The aluminum alloys possess high strength, ductility, castability, wear, and corrosion resistance. Due to such promising properties, aluminum alloy has wide applications in the aerospace and automotive industries. The present study, focused on the dry wear test of stir-cast hybrid aluminum metal matrix nano-composite (HAMNCs), fabricated using Al6061 (base alloy), graphene nanoplatelets (GNPs), and cerium oxide (CeO2). The reinforcements are added during stir casting in 1 to 3 weight percentages. The ASTM G99 standard was used to prepare the wear test specimens. The prepared test specimens were tested using pin-on-disc apparatus at four different loads (15 N, 30 N, 45 N, and 60 N). The worn-out surfaces are analyzed using the scanning electron microscope (SEM). It is found that the wear resistance of the hybrid nano-composite was enhanced with the addition of reinforcements. The lowest wear rate of 0.303 mm3/N-m was achieved with (3 wt% GNPs + 3 wt% CeO2) reinforcement in Al-6061 alloy. The coarser grain size and uniform dispersion were observed after examining the optical and SEM micrographs of the specimens, respectively. In future research work, the authors will expand this work by carrying out wear tests for the same pair at actual working settings and the same will be reported separately in subsequent research papers.

Experimental Study on Mechanical Behavior of Laterite Soil Treated with Quicklime

The present study examines the effect of lime stabilisation on the mechanical properties of laterite soil. Compaction tests were performed in order to obtain optimum moisture content (OMC) and maximum dry density (MDD) for untreated and lime treated laterite soil. A series of Unconfined compressive strength (UCS) tests were carried out on the specimen containing different percentages of lime. In preparing test specimens, laterite soil was initially compacted at their respective OMC and MDD conditions and allowed to cure for 0, 3, 7, 14 and 28 days before being tested. Results for the standard compaction test show an increasing trend for optimum moisture content (OMC), whereas maximum dry density (MDD) decreased as the concentration of lime increased. On the other hand, UCS results indicated that all percentages of lime treated laterite increased in strength with the curing period.

Strength Evaluation of Functionalized MWCNT-Reinforced Polymer Nanocomposites Synthesized Using a 3D Mixing Approach.

The incorporation of carboxyl functionalized multi-walled carbon nanotube (MWCNT- COOH) into a polymethyl methacrylate (PMMA) has been investigated. The resultant tensile and flexural mechanical properties have been determined. In this paper, a novel synthesis process for a MWCNT-reinforced polymer nanocomposite is proposed. The proposed method significantly eliminates the most challenging issues of the nano-dispersed phase, including agglomeration and non-homogeneous mixing within a given matrix material, and also resolves the issues occurring in conventional mixing processes. The results of scanning electron microscopy support these claims. This 3D-mixing process is followed by an extrusion process, using a twin-screw extruder for pristine MWCNT, and a compression molding process for COOH-MWCNT, to prepare test specimens for experimentally determining the mechanical properties. The test specimens are fabricated using 0.1, 0.5, and 1.0 wt.% MWCNT, with a remaining PMMA phase. The testing is conducted according to ASTM D3039 and ASTM D7264 standards. Significant improvements of 25.41%, 35.85%, and 31.75% in tensile properties and 18.27%, 48%, and 33.33% in flexural properties for 0.1, 0.5, and 1.0 wt.% COOH-MWCNT in PMMA, respectively, compared to non-functionalized MWCNTs, were demonstrated. The highest strength was recorded for the nanocomposite with 0.5 wt.% f-MWCNT content, indicating the best doping effect at a lower concentration of f-MWCNT. The proposed CNT-PMMA nanocomposite may be found suitable for use as a scaffold material in the domain of bone tissue engineering research. This type of research possesses a high strength requirement, which may be fulfilled using MWCNT. Furthermore, this analysis also shows a significant amount of enhancement in flexural strength, which is clinically required for fabricating denture bases.

Towards standardizing the preparation of test specimens made with material extrusion: Review of current techniques for tensile testing

Researchers and industries rely heavily on standardized testing methods to ensure products are designed and manufactured with high quality. With increasing use of additive manufacturing processes, such as material extrusion (MEX), there is a significant gap in material testing standards tailored for such components, and a lack of guidance on preparing appropriate test specimens with mesostructures that best represent the final part being analyzed. This paper aims to support the standardization of MEX material testing by reviewing the current methods used for preparing test specimens for tensile testing and proposing guidelines for implementation in a new standard. The need for standardization of MEX specimen preparation is addressed by analyzing the effects of slicing parameters on resulting tensile properties of the specimen. It is suggested that a standard should acknowledge these parameters, in addition to specimen geometry, toolpath optimization, printer and material specifications, so that they are appropriately selected for the test specimen by regarding the final part structure. Consideration of the proposed guidelines in a standardized method may enable comparisons between published results and support the development of MEX technology for use in advanced applications. • Material testing standards are incomplete for specimens made by material extrusion. • Test specimen preparation procedures found in literature are inconsistent. • Process parameters greatly influence tensile strength and stiffness. • Guidelines for a standard test specimen preparation procedure are proposed.

Experimental Evaluation of Wöhler Curve for Mild Steel Plates Manufactured In Nepal

This research work was carried out to explore the fatigue behavior of Mild Steel Plates manufactured in Nepal and determine the Wöhler Curve of the plates by preparing test specimens and conducting fatigue experiment of the specimens in the rotating cantilever bending fatigue test machine. The laboratory data thus obtained were plotted to generate the Wöhler Curve of the material. Along with the curve the Basquin’s Coefficients and Endurance limitup to 106 cycles were determined. Specimen was designed in accordance to ASME E 466-15 and the machining was done in accordance to IS 1075-1985 and then was subjected to various different loads. Exploratory tensile test of the material was also done in order to find out the proportion of the applied load with respect to the ultimate strength of the material. Surface crack was also inspected.Micro void coalescence and Micro cleavage formations were noticed in the fractured section.

Enhancement of impact toughness properties of Al 7075 alloy via double aging heat treatment

In this study, Charpy impact test specimens were prepared by cutting Al 7075 alloy according to ASTM-E23 standards. The prepared test specimens were dissolved in a single-phase region for 1 hour at 480°C in vacuum atmosphere and artificially aged at 120°C for 24 hours after quenching. After the first step aging heat treatment applied, the specimens were artificially aged for 5-50 hours at 180°C for the second time. Microstructural characterization and fracture surface analyzes of the specimens were determined using SEM (Scanning Electron Microscope) device, crystallographic analysis of the precipitated phases were determined using XRD (X-ray diffraction) device. The increase in the amount of ƞı phase (MgZn2) with increasing double aging heat treatment time was effective in increasing the strength. After 10 hours of double aging heat treatment, the impact toughness value is improved by 300% compared to the single aged condition.

Automatic Preparation of Specimens for Diagnostic Testing from a Diverse Range of Animals with the 2A Automatic Homogenization Processor

Automatic Preparation of Specimens for Diagnostic Testing from a Diverse Range of Animals with the 2A Automatic Homogenization Processor