Advancements in 3D printing technology have enabled the creation of highly efficient and cost-effective suppressors, offering significant safety benefits for firearm users. Exposure to firearm noise, even in controlled environments such as shooting ranges, poses serious health risks, necessitating improved noise reduction measures. This study explores the potential of 3D printing to produce novel suppressor designs that effectively reduce sound pressure levels in firearms, specifically focusing on their application with a .22 LR caliber rifle. Suppressors capable of reducing sound levels to below 135 dB, making them safe for adult use without hearing protection, were the primary focus. The research was conducted in two phases: initially, optimal suppressor designs were modeled using SolidWorks computational fluid dynamics (CFD), featuring innovations such as perforated baffles, additional expansion chambers, deep and curved expansion chambers, and perforated tubes extending along the suppressor's length. Following the simulation of these designs, live fire testing was conducted in a controlled shooting range environment. The results demonstrated that all tested designs effectively reduced sound pressure to safe levels. However, the suppressor with a conventional baffle layout supplemented by partitioned expansion chambers proved to be the most efficient, particularly when paired with subsonic ammunition. This study highlights the potential of 3D printing technology to revolutionize suppressor design, offering customizable solutions that enhance both user safety and environmental protection.

The safety and functionality of flexible photovoltaic (PV) racking systems critically depend on understanding the force and deformation behavior of wire ropes. This study establishes mechanical equilibrium equations to derive the deformation curve, maximum displacement, and maximum tension of wire ropes subjected to loading. Analytical dimensionless equations indicate that variations in the orientation of PV modules do not affect the structural stiffness or forces exerted on the wire ropes. Engineering calculations of maximum displacement and tension are compared with results from finite element simulations, revealing less than a 1% discrepancy between the analytical and numerical outcomes. Analysis of characteristic parameter curves in relation to prestress demonstrates that the maximum deflection span ratio decreases as prestress increases, while the maximum tensile stress rises with increasing prestress. The proposed formulas are validated as both accurate and practical, effectively reflecting the changes in wire rope forces with varying prestress levels. This study provides valuable insights for the mechanical analysis and structural design of flexible PV mounting systems, offering a robust reference for future engineering applications.

The aerodynamic and structural performance of aircraft wings constructed from Boron Aluminum Metal Matrix Composites (Boron Al MMC) and conventional aluminum alloys has been comprehensively evaluated through Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) studies. The CFD analysis was conducted using ANSYS CFX to investigate the aerodynamic behavior, while the FSI analysis was performed using ANSYS Structural to assess the interaction between fluid flow and structural response under various loading conditions. The findings have demonstrated that wings composed of Boron Al MMC exhibit superior performance in terms of strength, stiffness, and durability when compared to aluminum alloys. Under similar aerodynamic loads, the Boron Al MMC material maintained higher structural integrity, demonstrating a 2.28% reduction in equivalent stress, a 30.1% decrease in induced shear stress, a 69.12% reduction in induced deformation, and a 66.35% lower strain energy relative to the aluminum alloy. These results suggest that Boron Al MMC offers enhanced structural stability at high speeds, especially at speeds exceeding Mach 1, as well as under diverse flight conditions involving high G-forces. The significant reduction in deformation and stress concentrations indicates that Boron Al MMC provides improved resilience against damage under high aerodynamic loads. This analysis underlines the potential of Boron Al MMC as a promising material for aircraft wing construction, capable of delivering improved aerodynamic performance, extended service life, and heightened safety margins. Such properties make it a viable alternative to traditional materials, particularly in advanced aerospace applications where strength, stiffness, and durability are critical. The integration of Boron Al MMC could lead to significant advancements in the development of more efficient and reliable aircraft wings.

A torque-based optical fiber flow sensor has been designed and experimentally tested to assess its potential for fluid flow measurement. The sensor utilizes an optical fiber strength modulation principle to achieve flow detection. Detailed attention is given to the design of the sensor structure, including the sensor probe and fiber bundle probe, and the working principle of the torque-based flow sensor is systematically described. A theoretical model of the sensor is established, considering key parameters such as torque (m), radius (r), sensor joint stiffness (S_J), refractive index (n), and radius of curvature (R), which significantly affect its detection performance. Simulations are conducted to obtain Q-M curves under varying parameter conditions, revealing the relationship between sensor output and fluid flow rate. A gas flow detection experiment is subsequently performed on a custom-built experimental platform to evaluate the sensor’s practical performance. The results indicate that the sensor output decreases monotonically with increasing fluid flow for different parameter settings, demonstrating a good linear response within a specific detection range. It is found that the sensitivity of the sensor is influenced by the selection of critical performance parameters and the characteristics of the fluid being measured. For gas flow detection, the sensor output voltage shows an approximately linear decrease with the increase in gas flow. The comparison between simulation and experimental data confirms that both exhibit similar trends, thereby validating the sensor’s applicability in fluid flow detection. This study highlights the potential of torque-based optical fiber flow sensors for accurate and reliable fluid flow measurements.

A numerical model of a Gas Metal Arc Welding (GMAW)-based Wire Arc Additive Manufacturing (WAAM) process was developed using the Abaqus software, with validation performed against experimental data from existing literature. The model was employed to investigate the influence of heat input and cooling time on residual stress distribution, with particular focus on longitudinal residual stress. Minimal effect was observed with increasing heat input, whereas cooling time significantly affected stress distribution. The impact of unclamping was also examined. It was determined that for heat inputs of 4000 W and 4500 W, longitudinal residual stress decreased by approximately 10% after unclamping. In contrast, for a heat input of 5000 W, longitudinal residual stress increased by 12% following unclamping. Residual stress was found to accumulate predominantly at the interface between the substrate and the deposition wall. This study provides critical insights into the thermal and mechanical behavior of WAAM processes, contributing to a deeper understanding of stress management and control in additive manufacturing of B91 steel.