As the resources are declining globally, researchers are constantly looking for the development of new materials. The composite materials using natural fibers are one of the best solutions nowadays in this regard. In third-world countries, jute is produced abundantly. Moreover, banana is widely available due to their reproduction ability from an existing plant. This study involves the use of jute-glass fiber laminas and banana-glass fiber laminas with epoxy resin, individually, to produce hybrid laminated composites. Different Stacking orientations such as [0°/G/G/0°], [0°/G/G/30°], and [30°/G/G/30°] have been utilized for both jute and banana fibers to find the best hybrid laminated composite. The mechanical properties such as tensile, flexural, impact, hardness, and heat reversion properties along with some physical properties like density, specific gravity, and water absorption of these hybrid laminated composites have been tested according to the ASTM standards. The fracture surface has been examined using scanning electron microscopy (SEM) for microscopic visualization. It has been found from the experimental results that the jute-glass fiber composite shows better mechanical and physical properties, and among all the stacking orientations, [0°/G/G/0°] orientation provides higher tensile strength, flexural strength, and physical properties, whereas [0°/G/G/30°] orientation shows the better impact and hardness properties.

Purpose: This paper aims to understand the effect of extrusion conditions on the degree of foaming of polylactic acid (PLA) during three-dimensional (3D) printing. It was also targeted to optimize the slicing parameters for 3D printing and to study how the properties of printed parts are influenced by the extrusion conditions. Design/methodology/approach: This study used a commercially available PLA filament that undergoes chemical foaming. An extrusion 3D printer was used to produce individual extrudates and print samples that were characterized using an optical microscope, scanning electron microscope and custom in-house apparatuses. Findings: The degree of foaming of the extrudates was found to strongly depend on the extrusion temperature and the material feed speed. Higher temperatures significantly increased the number of nucleation sites for the blowing agent as well as the growth rate of micropores. Also, as the material feed speed increased, the micropores were allowed to grow bigger which resulted in higher degrees of foaming. It was also found that, as the degree of foaming increased, the porous parts printed with optimized slicing parameters were lightweight and thermally less conductive. Originality/value: This study fills the gap in literature where it examines the foaming behavior of individual extrudates as they are extruded. By doing so, this work distinguishes the effect of extrusion conditions from the effect of slicing parameters on the foaming behavior which enhances the understanding of extrusion of chemically foamed PLA.

The circular economic approach in polymer composite research has gained acceptance for offering low-cost, high-performance solutions. Sawdust-derived composites have drawn interest as alternatives in concrete and composite fabrication, addressing housing shortages and resource depletion. Sawdust concrete (SDC) and sawdust polymer composites (SDPC) are key areas under investigation, with SDC additionally aiding in carbon reduction in building materials. However, challenges arise due to sawdust’s inherent hydrophilicity, porosity, and lower strength. This study introduces a novel approach by identifying specific chemical treatments, including alkali and silane, which effectively enhance sawdust’s compressive and tensile strengths, moisture resistance, and durability, optimizing it for structural applications. The study evaluates SDC’s compressive strength based on treatment type, concentration, and curing time, examining physical properties such as water absorption, moisture sensitivity, and fiber-matrix adhesion. The unique contribution lies in a detailed optimization analysis, revealing conditions under which sawdust reaches structural-grade performance, expanding its potential in sustainable construction. For SPDC, tensile strength improvements are assessed under various chemical compositions, showing that specific polymers form stronger fiber-matrix bonds for greater stability. Morphological studies further explore fiber-matrix compatibility, hydrophobicity, and failure mechanisms. By advancing the understanding of treatment efficacy, this review positions sawdust as a viable, low-cost material alternative, establishing a foundation for sustainable innovation in construction and bio-composite research. These findings contribute to sawdust’s potential as a practical, eco-friendly building material.

Power transformers play a vital role in adjusting voltage levels during transmission. This study focuses on optimizing the structural design of power transformer tanks, particularly high-voltage (HV) tank walls, to enhance their mechanical robustness, performance, and operational reliability. This research investigates various stiffener designs and their impact on stress distribution and deformation through finite element analysis (FEA). Ten different configurations of stiffeners, including thickness, width, type, and position variations, were evaluated to identify the optimal design that minimizes stress and deflection while considering weight constraints. The results indicate that specific configurations, particularly those incorporating 16 mm thick H beams, significantly enhance structural integrity. Experimental validation through pressure testing corroborated the simulation findings, ensuring the practical applicability of the optimized designs. This study’s findings have implications for enhancing the longevity and reliability of power transformers, ultimately contributing to more efficient and resilient power transmission systems.

As a consequence of research on developing a speedy transportation system, Hyperloop is one of the best solutions now as smaller resistant forces are developed on the capsule body compared to conventional ground transportation systems due to movement in a vacuum and no contact with the ground. In this study, a capsule of an elliptical-shaped head and semicircular-shaped rear was chosen for analysis. Aerodynamic drags were calculated at different evacuated tunnel pressures. The computational regime was a 360 meters long tunnel. The inlet and outlet were pressure far-field boundaries while the wall was moving, with a Blockage Ratio (BR) of 0.36. Characteristics of different regions were identified in choked conditions. The drag was found to be lesser than the capsule of semicircular ends at different speeds. The pressure drag and friction drag were increased with the increase in velocity in the same tunnel pressure. By investigating different flow regions, it was found that a series of rhomboidal-shaped shock waves appear at high speeds. The formation and nature of this shock wave were also investigated, and found that it is caused due to shock wave and expansion wave interaction that results in the fall of pressure and temperature in the wake region.

This study investigates cellular negative stiffness honeycomb (NSH) structures in the prospect of energy absorption and vibration isolation. The energy absorption properties for different geometrical parameters have been investigated for a specific displacement in the range of linear compression. The force–displacement characteristics of NSH structures with various AM materials have been investigated using the finite element analysis method. The results have revealed the parametric relation of the NSH with the energy absorbed, specific energy absorption, stiffness, and compressive stress. The analysis highlights the NSH structures’ potential to enhance material efficiency and performance optimization, contributing to material and manufacturing engineering.