Pushkaraj D. Sonawane

This study presents an integrated experimental and finite element investigation into the structural performance of fused deposition modeled (FDM) transtibial prosthetic sockets fabricated from short carbon fiber reinforced polylactic acid (PLA–SCF). Patient-specific socket geometry was derived from 3D scanning of a clinical residual limb mold, reconstructed in CAD, and printed at 1:3 geometric scale FDM printer with 100% infill density, 0.2 mm layer height and vertical build orientation. Axial compression testing yielded a mean compressive strength of 1.072 ± 0.370 MPa and a maximum load of 15.872 kN exceeding the ISO 10,328 P6 structural requirement when scaled by dimensional similarity while a coefficient of variation of 34.5% identified filament moisture sensitivity as the primary source of inter-specimen variability. Low-cycle fatigue testing revealed progressive, non-catastrophic crack initiation within 90–100 cycles under proportionally scaled mid-stance loading of 50–150 N, with interlaminar debonding confirmed as the governing failure mechanism by SEM analysis. The mean inner surface roughness of Ra = 14.81 μm marginally satisfies the proposed Ra < 15 μm clinical criterion for FDM prosthetic sockets. Finite element analysis predicted a peak von Mises stress of 1.255 MPa at the distal region, agreeing with experimental results within 11.6%. These findings establish interlaminar fatigue resistance as the primary limitation of PLA–SCF for prosthetic applications and provide a reproducible experimental baseline to guide future design optimization and clinical translation.

This review explores various types of acoustic materials that are modified to enhance their sound absorption properties. Effective noise control relies on materials with high sound absorption coefficients (SAC) across a wide frequency range. Porous materials, such as foams and fibrous structures, are commonly used for mid to high-frequency absorption, while resonator-based materials, including Helmholtz resonators and micro-perforated panels, target low-frequency sounds. Natural fibres offer a sustainable alternative, and composite materials combine different mechanisms for broader spectral absorption. To further improve performance, materials can be modified physically (e.g., structural alterations), chemically (e.g., treatments or coatings), or through advanced techniques such as nanotechnology and additive manufacturing. Mathematical models help analyse their acoustic behaviour, guiding material optimization. This review highlights the ongoing advancements in acoustic materials, emphasizing the need for innovative modifications to meet modern noise control challenges in architectural, industrial, and automotive applications.

Additive manufacturing (AM) is an innovative procedure that can quickly create complex structures. By layering a material, a three-dimensional object is created using this technique. Every deposit of liquefied or partly liquefied material abides by the previous deposit. Fused deposition modelling’s (FDM) objective is to comprehend how varied interior structures influence the bending resistance of the printed samples and to investigate the impact of various infill patterns and percentages. The term “infill” describes the pattern of solid material used to fill a 3D-printed object's interior. It is utilized to give the printed part structural support and strength. Acrylonitrile butadiene styrene (ABS) material was chosen for this study as it offers a greater and superior finished plane along with dimensional stability. The infill pattern chosen for the flexural test study was the triangular pattern which includes different densities of infill percentages precisely, 25%, 50%, 75%, and 100%. A few specimens of ABS material having 100% infill density are put through a tensile test according to the ASTM D638. The ASTM D790 standard was used to make a model and test the flexural strength of the specimen. Line and triangle patterns provided the most ideal tensile and bending strength properties. This is likely because the deposited rasters are associated with the direction of loading. For line patterns with 100% infill, scanning electron microscopy (SEM) analysis showed a convincing connection between the microstructures and the rasters (porosity, voids, gap between beads and hole due to polymer pulled out). Furthermore, SEM analysis showed matrix failure and significant voids in a triangular pattern at infill densities of 25%, 50%, 75%, and 100%.

In this study, a Mg3Zn alloy and a Mg3Zn1HA nanocomposite were fabricated through disintegrated melt deposition, followed by the hot extrusion process. The specimens were subjected to fiber laser surface modification in air and demineralized water (DM) medium to determine the influence of the laser treatment medium on the microstructure, microhardness, grain size, and surface topography. During the laser treatment, the samples under the water medium produced a lower surface roughness when compared with the air medium. The atomic force microscope (AFM) surface topography scan showed the presence of surface modifications caused by the presence of nanohydroxyapatite (nHA) in the matrix, resulting in a 367.4% and 632.4% increase in the surface roughness (Ra) in the Mg3Zn1HA nanocomposite when compared with the Mg3Zn alloy in water and air media, respectively.