Search

This study investigated the mechanical performance of hybrid tubes made via roll-wrapping and enhanced with an aluminum mesh and epoxy matrix (AL-DMEM). The specimens included Basalt + Jute (BJAJB), Basalt + Bamboo (BBmABmB), Basalt + Banana (BBaABaB), Basalt + Hemp (BHAHB), and Basalt (BAB). The BBmABmB specimen showed the best mechanical properties with the highest peak crushing force, specific energy absorption, mean crushing force, and total energy absorption. The AL-DMEM integration improved load-bearing capacity and energy absorption, reducing matrix cracking and fiber breakage. Scanning electron microscopy and energy-dispersive X-ray analysis highlighted BBmABmB's robust reinforcement. Its superior structural integrity and aluminum content make it suitable for applications requiring high structural integrity, such as micromobility vehicles, highlighting the potential of ALDMEM-reinforced composites in advanced engineering applications. [ABSTRACT FROM AUTHOR]

The gyroid structure is a bio-inspired structure that was discovered in butterfly wings. The geometric design of the gyroid structure in butterfly wings offers a unique combination of strength and flexibility. This study investigated sandwich panels consisting of a 3D-printed gyroid structure core and carbon fiber-reinforced polymer (CFRP) facing skin. A filament fused fabrication 3D printer machine was used to print the gyroid cores with three different relative densities, namely 10%, 15%, and 20%. Polylactic acid (PLA) was used as the printing material for the gyroid. The gyroid structure was then sandwiched and joined by an epoxy resin between CFRP laminates. Polyurethane foam (PUF) was filled into the gyroid core to fill the cavity on the core for another set of samples. Flexural and compression tests were performed on the samples to investigate the mechanical behavior of the sandwiches. Moreover, the two-parameter Weibull distribution was used to evaluate the results statistically. As a result, the sandwich-specific facing stress and core shear strength from the three-point bending test of the composites increased with the increase in sandwich density. Core density controls the flexural characteristics of the sandwich. Adding PUF improves the deflection at the maximum stress and the sustained load after fracture of the sandwich. Compression strength, modulus, and energy absorbed by gyroid core sandwiches and their specific properties are higher than the PUF-filled gyroid core sandwiches at equal sandwich density. [ABSTRACT FROM AUTHOR]

In recent years, researchers have increasingly directed their focus toward the biomedical field, driven by the goal of engineering polymer systems that possess a unique combination of both electrical conductivity and biodegradability. This convergence of properties holds significant promise, as it addresses a fundamental requirement for biomedical applications: compatibility with biological environments. These polymer systems are viewed as auspicious biomaterials, precisely because they meet this critical criterion. Beyond their biodegradability, these materials offer a range of advantageous characteristics. Their exceptional processability enables facile fabrication into various forms, and their chemical stability ensures reliability in diverse physiological conditions. Moreover, their low production costs make them economically viable options for large-scale applications. Notably, their intrinsic electrical conductivity further distinguishes them, opening up possibilities for applications that demand such functionality. As the focus of this review, a survey into the use of biodegradable conducting polymers in tissue engineering, biomedical implants, and antibacterial applications is conducted. [ABSTRACT FROM AUTHOR]

This study aims to develop suitable formulations of geopolymer concrete (GPC) by varying the percentages of the geopolymer with aggregates and evaluating the performances in thermal and mechanical properties of palm kernel shell ash (PKSA)-GPC compared to rice husk ash (RHA)-GPC and ordinary Portland cement concrete (OPCC). Preliminary tests were conducted to select the best mix design ratios before casting the specimens. Then, the performance of the PKSA-GPC, RHA-GPC and OPCC specimens was evaluated based on their thermal performance and drying shrinkage. The mix designs of PKSA-GPC 70:30, PKSA-GPC 60:40, PKSA-GPC 50:50 and PKSA-GPC 66.6:33.3 were found to produce an acceptable consistency, rheological and thixotropic behaviour for the development of the GPC. PKSA-GPC showed a better thermal performance than the RHA-GPC and OPCC due to their strong and dense intumescent layers and slow temperature increment upon exposure to a high flame temperature from ambient temperature to 169 °C. The low molar ratio of the Si/Al present in the PKSA-GPC created a thermally stable intumescent layer. In the drying shrinkage test, PKSA-GPC 60:40 and RHA-GPC 60:40 shared an equal drying shrinkage performance (5.040%) compared to the OPCC (8.996%). It was observed that microcrack formation could significantly contribute to the high shrinkage in the PKSA-GPC 50:50 and RHA-GPC 70:30 specimens. The findings of this study show that PKSA could be incorporated into GPC as a fire-retardant material due to its capability of prolonging the spread of fire upon ignition and acting as an alternative to the conventional OPCC. [ABSTRACT FROM AUTHOR]

Composite structures with a pure glass composite facesheet and an aluminum honeycomb core are widely used in aircraft interiors. Because impact-related problems are related to structural integrity and safety performance, the behavior of these structures under impact loading is critical. Due to their promising performance, lower cost, and low environmental impact, hybrid composites have recently become one of the most widely researched composite materials in the research field. This paper aims to investigate the impact behavior of nonhybrid glass and the glass partially replaced with a flax and kenaf hybrid composite facesheet caused by a low-velocity impact. The specimens were impacted with different impacted energies, such as 10, 20, and 30 J. All nonimpacted and impacted samples were tested and compared for postimpact flexural (three-point bending) behavior to analyze the residual strength of sandwich structures after impact. The results revealed that the hybrid composite face sheet outperformed the glass composite sandwich structure. The hybrid composite face sheet allowed the impactor to penetrate deeper, resulting in better energy absorption than the glass composite. Compared to nonimpacted specimens, the glass and hybrid face sheet combinations demonstrated comparable residual bending performance. Highlights • Experimental analysis shows the impact resistance (low-velocity impact test) and residual load-carrying capacity (three-point bending test) of glass and hybrid composite face sheets. • Hybrid face sheets show excellent energy-absorbing capability compared to glass one. • The residual flexural strength of the glass and hybrid composites was comparable to that of nonimpacted samples. • The peel strength achieved in this study using the pre-cure fabrication process was significantly higher than the peel strength achieved using prepreg face sheets. • Reinforcing the composite face sheet of the sandwich structure by partially replacing the glass with flax and kenaf fiber exhibited comparable performance. [ABSTRACT FROM AUTHOR]