The machining of Fiber Metal Laminates (FMLs), such as glass laminate aluminum reinforced epoxy (GLARE), presents significant challenges due to the varying mechanical and thermal properties of its constituent materials. This study investigates the effects of cooling conditions and machining parameters on thrust force, surface roughness, and hole quality in FMLs. A comparative analysis of two hole-making techniques—twist drilling and helical milling—is performed on two thicknesses of GLARE, under both Minimum Quantity Lubrication (MQL) and dry conditions. The experimental work utilized the Response Surface Methodology (RSM) to assess the impact of spindle speed, feed rate, and cooling conditions on thrust force, torque, surface roughness, and hole quality. Results show that helical milling significantly reduces thrust force by 66% to 81% compared to twist drilling, although it requires a 300% increase in machining time. MQL was effective in decreasing thrust force and surface roughness in both methods. The thicker GLARE samples experienced a 17% to 32% increase in thrust force, leading to higher surface roughness. Spindle speed influenced thrust force by up to 60.68% in twist drilling, whereas feed rate showed the most significant effect (64.19%) in helical milling. This study highlights the advantages of helical milling in reducing machining forces and improving surface quality, despite its longer process time. The results provide useful information for machine configuration optimization, particularly for aerospace applications that frequently use FMLs like GLARE.
The article introduces a novel antenna design aimed at addressing the demands of communication technologies. The antenna configuration involves a circular patch coupled with a coplanar waveguide (CPW) and incorporates circular split-ring resonators (SRR) on a Polydimethylsiloxane (PDMS) substrate. The use of PDMS, a flexible and durable material, enhances the antenna's mechanical properties and allows for versatility in various environments. The designed antenna has an overall area of 50x40mm2. The innovative design exhibits resonances at distinct frequencies, specifically 3.3 GHz, 9.7 GHz, and 10.5 GHz, with a return loss of -61.86dB, -31.72dB, -51.81dB, and VSWR of 0.01, 0.5, 0.2 catering to the requirements of wireless communications, radar systems, and satellite applications, respectively. The requirement of the high-end communication module is satisfied by the array configuration resulting in improved directivity and gain. The array module of 2x2 and 4x4 is simulated and analyzed. The choice of the array is selected based on the end application. The requirement of the high-end communication module is satisfied by the array configuration resulting in improved directivity and gain. The array module of 2x2 and 4x4 is simulated and analyzed. The choice of the array is selected based on the end application.
The novelty of this study is to consider the vibration analysis of a sandwich structure using shear and normal deformation beam theory (SNDBT) with a porous core and various reinforcement materials, including carbon nanorods (CNRs), graphene platelets (GPLs), and carbon nanotubes (CNTs), by considering the size effect based on modified couple stress theory (MCST) or nonlocal strain gradient theory (NSGT) on various elastic foundation such as Winkler, Pasternak, and Kerr, simultaneously. Also, each layer in the microbeam has different mechanical properties as a function of temperature. The governing equations of motion are derived using Hamilton's principle and the energy approach by considering the variational method, and then these equations are solved using Navier's method. The results are compared with those recently published by other scientists. The purpose of this study is to present a comprehensive and efficient innovative analytical framework for understanding the vibration behavior of a sandwich microbeams with different cores and reinforcements, and types of elastic foundations. In the higher-order shear and normal deformation theory by applying the stretching functions, the proposed model offers advantages that can increase the computational efficiency. In addition, a comprehensive parametric study is carried out to evaluate the effect of various properties, including porosity distributions, small-scale parameters, different elastic foundations, thickness, axial wave number, small-scale theories, volume fraction, and different reinforcements such as GPLs, CNTs, and CNRs. It is concluded that GPLs have the highest frequency, and CNRs have the lowest frequency. Also, by increasing the volume fraction of the reinforcements, the natural frequency of the sandwich microbeam increases for GPLs by 10%, the CNTs by 7%, and the CNRs by 4%. The current study shows that the considering of an elastic foundation for a beam has been demonstrated to result in an increase in the frequencies. Furthermore, the results with and without the thickness stretching effect show that the shear and normal beam theory improves the results. The natural frequency increases by 67.4%, when FG-XX is compared to FG-UU face sheets. It decreases by 24.8% when FG-OO is compared to FG-UU. The sandwich beams are compared to those without reinforcement.
Modern manufacturing techniques have been significantly transformed by additive manufacturing (AM). Because of its capabilities like customized part manufacturing and, the ability to manufacture intricate and complex parts with reduced waste of material, additive manufacturing is becoming more popular. However, the properties of the parts manufactured by this method significantly vary with the variation in process parameters. Optimizing these parameters helps to extract enhanced mechanical properties. In addition, lattice structures have created new possibilities for increasing strength while lowering part weight through optimized lattice structures. The effect of lattice structure and process parameters on the specimen made using the fused deposition method (FDM) is the major focus of this study. In this work, three distinct TPMS-base (Triply Periodic Minimal Surfaces) lattice architectures are examined for a range of layer height levels. Investigations are conducted using the L9 orthogonal array. The FDM technique uses PLA plastic filament. The Taguchi method was used for optimization, and samples were evaluated on the UTM and Izod impact testing machines. Moreover, an ML model is created by applying machine learning to the collected data. In tensile and impact test data, neural network and Gaussian process regression models showed low error rates and predicted good accuracy. The neural network model for the flexural test data showed a moderate level of accuracy, suggesting potential for improvement. The models' performance was highlighted by their low RMSE, MSE, and MAE values, which show that they can predict material properties. The overall findings indicated that layer height has less impact on tensile and flexural strength than lattice structure. In contrast to the lattice structure, layer height influences the toughness.
Aeroelastic vibrations, caused by the complex interaction between aerodynamic forces and the structural dynamics of wind turbine blades, are a major contributor to fatigue, structural damage, reduced efficiency, and increased maintenance costs in wind turbine systems. Addressing this issue is critical for enhancing wind turbine’s operational performance, durability, and lifespan, making vibration control a key focus in the renewable energy industry. This paper investigates the Synchronized Switch Damping (SSD) modal method, a nonlinear control technique specifically chosen for its ability to efficiently mitigate aeroelastic vibrations by targeting and suppressing unwanted vibration modes. By synchronizing a piezoelectric component with a designated electrical circuit in harmony with the blade's movement, the SSD modal method provides precise and adaptive vibration control. Our study demonstrates the effectiveness of the Semi-active Modal SSD approach, achieving a notable 30.42% reduction in blade vibration. This substantial reduction enhances not only the overall performance but also the longevity of wind turbine blades, offering a significant advancement in vibration control strategies and contributing to the development of more reliable and efficient wind energy systems.
