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The purpose of this paper is to explore and investigate the mechanical as well as bacterial characteristics of chemically treated waste natural fiber inserted three-dimensional structures (NFi3DS) produced with fused filament deposition (FFD) for biomedical applications.

In this work, a novel approach has been used for developing the customized porous structures particularly for scaffold applications. Initially, raw animal fibers were collected, and thereafter, the chemical treatment has been performed for making their wise utility in biomedical structures. For this purpose, silk fiber and sheep wool fibers were used as laminations, whereas polylactic acid was used as matrix material. A low-cost desktop time additive manufacturing setup was used for making the customized and porous parts by considering type of fiber, number of laminates, infill density and raster angle as input parameters.

The results obtained after using design of experimental technique highlighted that output characteristics (such as dimensional accuracy, hardness, three-point bending strength and bacterial test) are influenced by input parameters, as reported in the obtained signal/noise plots and analysis of variance. Optimum level of input parameters has also been found through Taguchi L9 orthogonal array, for single parametric optimization, and teaching learning-based algorithm and particle swarm optimization, for multiple parametric optimization. Overall, the results of the studies supported the use of embedded structures for scaffold-based biomedical applications.

Presently, NFi3DS were produced by using the hand-lay-based manual approach that affected the uniform insert’s distribution and thickness. It is advised to use the automatic fiber placement system, synced with a three-dimensional printer, to achieve greater geometrical precision.

As both natural fibers and polymer matrix used in this work are well established for their biological properties, hence the methodology explored in this work will help the practitioners/academicians in developing highly compatible scaffold structures.

The present work defines a new practice where the researchers can use natural fibers to reduce the cost associated with fabrication of customized scaffold prints.

The development of natural fiber embedded FFD-based structures is not yet explored for their feasibility in biomedical applications.

Gas metal arc-based directed energy deposition (GMA-DED) process experiences residual stress (RS) developed due to heat accumulation during successive layer deposition as a significant challenge. To address that, monitoring of transient temperature distribution concerning time is a critical input. Finite element analysis (FEA) is considered a decisive engineering tool in quantifying temperature and RS in all manufacturing processes. However, computational time and prediction accuracy has always been a matter of concern for FEA-based prediction of responses in the GMA-DED process. Therefore, this study aims to investigate the effect of finite element mesh variations on the developed RS in the GMA-DED process.

The variation in the element shape functions, i.e. linear- and quadratic-interpolation elements, has been used to model a single-track 10-layered thin-walled component in Ansys parametric design language. Two cases have been proposed in this study: Case 1 has been meshed with the linear-interpolation elements and Case 2 has been meshed with the combination of linear- and quadratic-interpolation elements. Furthermore, the modelled responses are authenticated with the experimental results measured through the data acquisition system for temperature and RS.

A good agreement of temperature and RS profile has been observed between predicted and experimental values. Considering similar parameters, Case 1 produced an average error of 4.13%, whereas Case 2 produced an average error of 23.45% in temperature prediction. Besides, comparing the longitudinal stress in the transverse direction for Cases 1 and 2 produced an error of 8.282% and 12.796%, respectively.

To avoid the costly and time-taking experimental approach, the experts have suggested the utilization of numerical methods in the design optimization of engineering problems. The FEA approach, however, is a subtle tool, still, it faces high computational cost and low accuracy based on the choice of selected element technology. This research can serve as a basis for the choice of element technology which can predict better responses in the thermo-mechanical modelling of the GMA-DED process.

The main purpose of this work is to explore the erosion wear characteristics of additively manufactured aluminium alloy. Additive manufacturing (AM), also known as three-dimensional (3D) manufacturing, is the process of manufacturing a part designed in a computer environment using different types of materials such as plastic, ceramic, metal or composite. Similar to other materials, aluminum alloys are also exposed to various wear types during operation. Production efficiency needs to be aware of its reactions to wearing mechanisms.

In this study, quartz sands (SiO₂) assisted with oxide ceramics were used in the slurry erosion test setup and its abrasiveness on the AlSi10Mg aluminum alloy material produced by the 3D printer as selective laser melting (SLM) technology was investigated. Quartz was sieved with an average particle size of 302.5 µm, and a slurry environment containing 5, 10 and 15% quartz by weight was prepared. The experiments were carried out at the velocity of 1.88 (250 rpm), 3.76 (500 rpm) and 5.64 m/s (750 rpm) and the impact angles 15, 45 and 75°.

With these experimental studies, it has been determined that the abrasiveness of quartz sand prepared in certain particle sizes is directly related to the particle concentration and particle speed, and that the wear increases with the increase of the concentration and rotational speed. Also, the variation of weight loss and surface roughness of the alloy was investigated after different wear conditions. Surface roughness values at 750 rpm speed, 10% concentration and 75° impingement angle are 0.32 and 0.38 µm for 0 and 90° samples, respectively, with a difference of approximately 18%. Moreover, concerning a sample produced at 0°, the weight loss at 250 rpm at 10% concentration and 45° particle impact angle is 32.8 mg, while the weight loss at 500 rpm 44.4 mg, and weight loss at 750 rpm is 104 mg. Besides, the morphological structures of eroded surfaces were examined using the scanning electron microscope to understand the wear mechanisms.

The researchers verified that this specific coating condition increases the slurry wear resistance of the mentioned steel. There are many studies about slurry wear tests; however, there is no study in the literature about the quartz sand (SiO₂) assisted slurry-erosive wear of AlSi10Mg alloy produced with AM by using SLM technology. This study is needed to fill this gap in the literature and to examine the erosive wear capability of this current material in different environments. The novelty of the study is the use of SiO₂ quartz sands assisted by oxide ceramics in different concentrations for the slurry erosion test setup and the investigations on erosive wear resistance of AlSi10Mg alloy manufactured by AM.

This paper aims at erosion wear experimentation conducted on two piping materials, namely SS202 and SS304 to establish the effect of rotational speed, concentration and time period.

Erosion wear because of slurry flow is investigated using a slurry erosion pot tester. Fly ash is taken as erodent material having different solid concentrations lie in range 30 to 60per cent (by weight). Experiments are performed at four different speeds, i.e. 600; 900; 1,200; and 1,500 rpm for time duration of 90, 120, 150 and 180 min, respectively. To enhance erosion wear resistance of both piping materials, high-velocity-oxy-fuel coating technique is used to deposit WC-10Co4Cr coating. The parametric influence of erosion wear is optimized using Taguchi method.

The results show that significant improvement in erosion wear resistance is observed by deposition of WC-10Co4Cr coating. It is observed that rotational speed is found as highly influencing parameter followed by concentration and time duration. Parametric investigation of erosion wear is helpful to develop a procedure for minimizing the erosion wear in pipeline for the flow of solid-liquid mixture.

Slurry erosion wear of WC-10Co4Cr coated stainless steel (SS202 and SS304) is substantiated by extensive microstructural analysis and optimization technique.

The purpose of this paper is to fabricate acrylonitrile-butadiene-styrene (ABS)/high impact polystyrene (HIPS) based multi-material geometries using a low cost polymer printer. At the same time, efforts have been made to investigate the mechanical characteristics of the obtained prints and to perform the optimization using the Taguchi-Grey (TGRA) method.

Initially, the feedstock materials were in-house fabricated in the form of filament wires, workable with fused filament fabrication (FFF) technique, of 1.75 ± 0.1 mm diameter by using a single screw extruder. Multi-material structures were fabricated using variable parameters (such as: raster angles, layer height, fill density and solid layers) and the experimentation was conducted as per Taguchi L18 array. Mechanical responses obtained by performing tensile, impact and bending test were studied in response to input variables and ultimately optimized settings were obtained, for individual as well as multiple parameters). Scanning electron microscopy (SEM) analysis was performed to analyze the fractured surfaces.

The Signal/Noise (S/N) plots for the quality characteristics highlighted that selected input parameters significantly influenced the obtained values for tensile strength, impact strength and flexural strength. Micrographs of the fractured specimens showed the occurrence of brittle fracture with higher levels of perimeter, infill density and solid layers. The extent of delamination was also increased under the bending load and further increased by increasing solid layers.

The results of the study strongly advocated the utility of fabricated multi-materials structures in automotive, aerospace and other manufacturing industries.

This work represents the fabrication, testing and analysis of polymer-based multi-material structures for engineering applications.

Additive manufacturing (AM), a rapidly evolving paradigm, has shown significant advantages over traditional subtractive processing routines by allowing for the custom creation of structural components with enhanced performance. Numerous studies have shown that the technical qualities of AM components are profoundly affected by the discovery of novel metastable substructures in diverse alloys. Therefore, the purpose of this study is to determine the effect of cell structure parameters on its mechanical response.

Initially, a methodology was suggested for testing porous materials, focusing on static tensile testing. For a qualitative evaluation of the cellular structures produced, computed tomography (CT) was used. Then, the CT scanner was used to analyze a sample and determine its actual relative density, as well as perform a detailed geometric analysis.

The experimental research demonstrates that the mechanical properties of a cell’s structure are significantly influenced by its shape during formation. It was also determined that using selective laser melting to produce cell structures with a minimum single-cell size of approximately 2 mm would be the most appropriate method.

Further studies of cellular structures for testing their static tensile strength are planned for the future. The study will be carried out for a larger number of samples, taking into account a wider range of cellular structure parameters. An important step will also be the verification of the results of the static tensile test using numerical analysis for the model obtained by CT scanning.

The fabrication of metallic parts with different cellular structures is very important with a selective laser melted machine. However, the determination of cell size and structure with mechanical properties is quiet novel in this current investigation.

The purpose of this study is to find the best geometries among the cylindrical, enamel and honeycomb geometries based upon the mechanical properties (tensile test, compression test and shear test). Further this obtained geometry could be used to fabricate products like exoskeleton and its supporting members.

The present research focuses on the mechanical testing of cylindrical, enamel and honeycomb-shaped parts fabricated through multi-jet printing (MJP) process with a wall thickness of 0.26, 0.33, 0.4 and 0.66 mm. The polymer specimens (for tensile, compression and shear tests) were fabricated using a multi-jet fusion process. The experimental results were compared with the numerical modelling. Finally, the optimal geometry was obtained, and the influence of wall thicknesses on various mechanical properties (tensile, compression and shear) was studied.

In comparison to cylindrical, enamel structures the honeycomb structures required less time to fabricate and had lower tensile, compressive and shear strengths. The most efficient geometry for fully functional parts where tensile, compressive and shear forces are present during application – cylindrical geometry is preferred followed by enamel, and then honeycomb. It was found that as the wall thickness of various geometries was increased, their ability to withstand tensile, compressive and shear loads also enhanced. The enamel shape structure exhibits greater strain energy storage capacity than other shape structures for compressive loads, and the strength to resist the compressive load will be lower. In the case of cylindrical geometries for tensile loading, the resisting area toward the loading will be higher in comparison to honeycomb- and enamel-based structures. At the same time, the ability to store the stain energy is less. The results of the tensile, compression and shear load finite element analysis using ANSYS are in agreement with those of the experiments.

From the insight of literature review, it is found that a wide range of work is done on fused deposition modeling (FDM) process. But in comparison to FDM, the MJP provide the better dimensional accuracy and surface properties (Lee et al., 2020). Therefore, it is observed that past research works not incorporated the effect of wall thickness of the embedded geometries on mechanical properties of the part fabricated on MJP (Gibson, n.d.). Hence, in this work, effect of wall thickness on tensile, compression and shear strength is considered as the main factor for the honeycomb, enamel and cylindrical geometries.

A nut bolt joint is a primary device that connects mechanical components. The vibrations cause bolted joints to self-loosen. Created by motors and engines, leading to machine failure, and there may be severe safety issues. All the safety issues and self-loosen are directly and indirectly the functions of the accuracy and precision of the fabricated nut and bolt. Recent advancements in three-dimensional (3D) printing technologies now allow for the production of intricate components. These may be used technologies such as 3D printed bolts to create fasteners. This paper aims to investigate dimensional precision, surface properties, mechanical properties and scanning electron microscope (SEM) of the component fabricated using a multi-jet 3D printer.

Multi-jet-based 3D printed nut-bolt is evaluated in this paper. More specifically, liquid polymer-based nut-bolt is fabricated in sections 1, 2 and 3 of the base plate. Five nuts and bolts are fabricated in these three sections.

Dimensional inquiry (bolt dimension, general dimensions’ density and surface roughness) and mechanical testing (shear strength of nut and bolt) were carried out throughout the study. According to the ISO 2768 requirements for the General Tolerances Grade, the nut and bolt’s dimensional examination (variation in bolt dimension, general dimensions) is within the tolerance grades. As a result, the multi-jet 3D printing (MJP)-based 3D printer described above may be used for commercial production. In terms of mechanical qualities, when the component placement moves from Sections 1 to 3, the density of the manufactured part decreases by 0.292% (percent) and the shear strength of the nut and bolt decreases by 30%. According to the SEM examination, the density of the River markings, sharp edges, holes and sharp edges increased from Sections 1 to 3, which supports the findings mentioned above.

Hence, this work enlightens the aspects causing time lag during the 3D printing in MJP. It causes variation in the dimensional deviation, surface properties and mechanical properties of the fabricated part, which needs to be explored.

3D printing is gaining attention in the medical sector for the development of customized solutions for a wide range of applications such as temporary external implants. The materials used for the manufacturing process are critical, as they must provide biocompatibility and adequate mechanical properties. This study aims to evaluate and model the influence of the printing parameters on the mechanical properties of two biocompatible materials.

In this study, the mechanical properties of 3D-printed specimens of two biocompatible materials (ABS medical and PLActive) were evaluated. The influence of several printing parameters (infill density, raster angle and layer height) was studied and modelled on three response variables: ultimate tensile strength, deformation at the ultimate tensile strength and Young’s modulus. Therefore, statistical models were developed to predict the mechanical responses based on the selected printing parameters.

The used methodology allowed obtaining compact models that show good fit, particularly, for both the ultimate tensile strength and Young’s modulus. Regarding the deformation at ultimate tensile strength, this output was found to be influenced by more factors and interactions, resulting in a slightly less precise model. In addition, the influence of the printing parameters was discussed in the work.

The presented paper proposed the use of statistical models to select the printing parameters (infill density, raster angle and layer height) to optimize the mechanical response of external medical aids. The models will help users, researchers and firms to develop optimized solutions that can reduce material costs and printing time but guaranteeing the mechanical response of the parts.

Introduction: Commercial banks play a vital role in the global economy, facilitating economic growth and providing essential financial services. As key intermediaries between savers and borrowers, these institutions operate in a dynamic and complex environment characterised by various risk factors that can significantly impact their profitability and overall stability. Understanding the interconnected relationships between credit risk, interest rate risk, liquidity risk, and profitability is crucial for effective risk management strategies and the development of appropriate regulatory frameworks.

Purpose: Commercial banks play a critical role in the global economy by facilitating economic growth and providing financial services. This study examines the interconnected relationships between credit risk, interest rate risk, liquidity risk, and profitability in commercial banking.

Methodology: The sample consists of licenced scheduled commercial banks on the Bombay Stock Exchange (BSE) from 2015 to 2022. Using the Smart PLS-SEM 3.0 path analysis technique, the study evaluates the combined influence of these risk factors on profitability and provides evidence-based recommendations for risk management strategies.

Findings: The findings can assist banks in enhancing their risk management practices, and regulators in developing appropriate regulatory frameworks. By understanding the key risk factors and their impact on profitability, banks and regulators can mitigate risks, enhance transparency, and promote stability within the banking sector.

Significance/value: The value of this study lies in its focus on the interconnectedness of risk factors, profitability, and the potential implications for decision-making, risk management strategies, regulatory frameworks, and the overall stability of the commercial banking sector.