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This study investigates the impact of Casimir, Van der Waals, and electrostatic forces on nanomechanical switches' thermomechanical and free vibration behavior. The analysis is conducted using a novel higher-order beam theory and the nonlocal strain gradient elasticity. The motion equations of the nanosensor/switch beam are derived using Hamilton's principle and solved using Navier's method for general boundary conditions. The nanoswitch is composed of electroelastic barium-titanate (BaTiO3) and magnetostrictive cobalt-ferrite (CoFe2O4) materials, which are modeled using a power-law approach to account for functionally graded material property variations across the beam's thickness. The impact of different parameters, such as Casimir, Vander Waals, electrostatic forces, and variations in material composition, size parameters, and gap distance, on a nanoswitch system's bucking and free vibration is comprehensively examined. With the intermolecular and electrostatic forces, the temperature dependency of barium-titanate and cobalt-ferrite nanoswitch materials, which have not been extensively studied in any previous research, is considered in the modeling of free vibration, and the buckling behavior of a nanoswitch for the first time. This research represents the first comprehensive analysis of these factors. Considering the investigated parameters, the study's findings can provide helpful insights into developing micro/nano-electromechanical systems, including switches, sensors, and actuators. [ABSTRACT FROM AUTHOR]

This work examines thermo-mechanical bending wave propagation in a sandwich nanobeam using advanced sandwich nanobeam and nanolocal strain gradient elasticity theories. The sandwich nanobeam is a unique structure with biocompatible ceramic ZrO2 and metal Ti6Al4V on the top and bottom sides. Sandwich nanobeam cores have functionally graded materials. This combination gives the nanobeam distinctive qualities and opens up many uses in diverse industries. The wave propagation equation is computed by applying the Navier method to the medium's thermal, Lorentz, and viscoelastic equations of motion. The sandwich nanobeam is analyzed using four distinct models, taking into account its composition of ceramic and metal materials. The various factors that affect sandwich nanobeam bending wave propagation have been extensively studied. In the scenario where the magnetic field intensity is Hm = 0, an increase in temperature difference causes the wave frequency of all models (except Model 2) to decrease to zero, resulting in buckling. In Model 2, the sandwich nanobeam exhibits a phase velocity of 0.43 Km/s at ΔT = 0, which subsequently decreases by ∼9% to 0.39 km/s at ΔT = 500. These factors include the strength of the magnetic field, the impact of thermal loads, the nonlocal effect, the dimensions of the sandwich nanobeam, and the foundation's influence. The findings of this research will help build nanosensor systems that can work in aerospace applications under extreme temperatures. These findings will contribute to the optimization of the design process, ensuring the reliability and functionality of the nanosensors under severe thermal conditions. [ABSTRACT FROM AUTHOR]

The thermal vibration and buckling behavior of a functionally graded nanoplate are examined in this study. The nanoplate is made up of a silicon nitride/stainless steel core plate and two cobalt-ferrite/barium-titanate face plates. Four alternative porosity models were used to simulate the porosity of the nanoplate, and numerous variables that can affect the nanoplate's behavior were taken into account. The study found that the thermomechanical behavior of nanoplates with magneto-electro-elastic face layers and a functionally graded porous core plate is affected by material gradation indices, porosity ratios, nonlocal variables, and different core plate material porosity models. [ABSTRACT FROM AUTHOR]

In this study, the researchers have attempted to reinforce ZK60 alloys with 5% SiC, 10% SiC, 5% B4C, 10% B4C and 5%SiC + 5%B4C microparticles and investigated the dry wear behavior of these composites. The reinforced composites were produced by the stirred casting method under the atmosphere of SF6. The high-temperature oxidation tendency of Mg and B elements can cause the oxidized-unsuccessful product in the stirred casting process. Therefore, the researchers used the semi-solid temperature stirring method in production as a new solution. The reinforced composites were homogenized at 420 °C for 24 hours and extruded at a rate of 2.25. Following the production process, all samples underwent microstructural characterization analyses, hardness tests, compression tests and dry wear tests. Comparative analysis was done between the results of unreinforced ZK60 alloy and composites from compression and wear tests. This study's results reveal a superior enhancement; the addition of 5% SiC increased the compressive strength of ZK60 alloy by 15%, while the addition of 5% B4C increased by 26%. Furthermore, adding the 5%SiC reinforcement reduced the wear rate by 4.3%, and the 5% B4C reinforcement reduced the wear rate by 11.1%. [ABSTRACT FROM AUTHOR]

In this study, an Al5083-H111 alloy was divided into two different parameters without heat treatment and by applying homogenization heat treatment. In the homogenized Al5083 sample, it helped to make the matrix structure more homogeneous and refined and distribute intermetallic phases, such as the Al-Mg phase (Mg2Al3) and Al-Fe phases, more evenly in the matrix. There was an increase in the hardness of the homogenized sample. The increase in hardness is due to the material having a more homogeneous structure. Corrosion tests were applied to these parameters in NaCl and NaOH. It is observed that Al5083 samples before and after heat treatment show better corrosion resistance and less weight loss in NaOH and NaCl environments. It was observed that the fracture resistance of the alloy in the NaOH solution was lower, and the weight loss was higher than the alloy in the NaCl solution. Wear tests were performed on two different parameters: a dry environment and a NaOH solution. Since the NaOH solution has a lubricating effect on the wear surface of the sample and increases the corrosion resistance of the oxide layers formed, the wear resistance of the alloys in dry environments was lower than the wear resistance of the alloys in the NaOH solution. A hydrogen evolution test was performed on the samples in the NaOH solution, and the results were recorded. Hydrogen production showed higher hydrogen output from the homogenized sample. Accordingly, a higher corrosion rate was observed. [ABSTRACT FROM AUTHOR]

This study investigated the V-bending process of 1.2 mm thick SCGADUB1180 advanced-high-strength steel sheet plate by experimental and finite element method, and its springback behaviour was investigated in detail. In the experiments, 27 different V-bending experiments were modeled in three different punch radii (3mm, 6mm, 9mm), three different bending angle values (60°, 90° 120°), three different rolling directions (0°, 45°, 90°). In the experiments created with these input parameters, the effect of the sheets on the springback was investigated by comparing the experimental data with different material models. 108 analyses were performed for four different finite element models (Hill-48, Barlat-89, Hill-48-kinematic, Barlat-89-kinematic). It was analyzed that the Barlat-89-kinematic strain hardening model was the closest model to the experimental results. In addition, with the help of the Minitab 18.0 statistics program, how well the finite element model data agreed with the experimental results was analyzed. It was observed that the variation of punch radius (83.03%) and bending angle (8.51%) had a significant effect on the springback behaviour of the sheet. As the punch radius increased, the springback values increased. At the highest parameter level, where the bending angle was 120°, the springback values decreased. The highest springback occurred at 90° bending angle.. [ABSTRACT FROM AUTHOR]

Purpose: In this study, a new train-track-bridge interaction system (TTBIS) is modelled, and the interaction of the system is analysed to calculate the dynamic responses of the (TTBIS). Considering the lateral and vertical dynamic movements, the entire train is realistically modelled with 31 degrees of freedom. Methods: The track system is realistically modelled as flexible rail, and the infrastructure system supporting the rail with eight parameters. So, the track system consists of flexible rail, two parameter rail pad, sleeper, ballast parameters. The bridge was modelled using thin beam theory and integrated motion equation was obtained using the Lagrange method. The analytical solution of motion equation was conducted by setting up an algorithm using the Runge–Kutta method with a specially written code. Results: As a result of the analyses made, the length of the bridge is 50 m or less, which does not affect the vertical movements of the train. In addition, Thanks to the track system, the dynamic responses affecting the train have been reduced. It is also understood that the vertical dynamic behavior of the train is a minimum in every four wagons. Conclusion: As the significance of this research, it was seen that bridge flexibility, natural vibration frequency, track parameters, travel speed, and the number of wagons have essential effects in terms of safe travel of high-speed-train. [ABSTRACT FROM AUTHOR]

The novelty of this study is to model and investigate the free and forced thermal vibration and buckling behaviors of a porous functionally graded magneto-electro-elastic (MEE) nanoplate made of barium-titanate and cobalt-ferrite and subjected to moving loads. In the modeling, the strains are assumed to originate from classical mechanics, thermal expansion, electroelastic, and magnetostrictive properties, nonlocal elasticity, and strain gradient elasticity, and the motion equations of MEE nanoplate are obtained by Hamilton's principle Considering various cases, the effects of thermal stresses, magneto-electro-elastic coupling, externally applied electric and magnetic field potential, nonlocal properties (nonlocal and material size parameters), porosity volume fraction on the free vibration and buckling behavior have been studied. Additionally, the forced response to the moving load for various cases of the velocity of the load is also investigated. It is observed that the free-response and buckling of the nanoplate vary with the material composition, externally applied electrical and magnetic fields, temperature rise, and porosity volume fraction. Furthermore, it is also noticed that the velocity of the load is the most influential factor in the forced response of the MEE nanoplate. Moreover, the material composition of the nanoplate characterizes the magneto-electro-elastic response depending on the amounts of barium-titanate (electro-elastic) and cobalt-ferrite (magnetostrictive). The stiffness of the MEE nanoplate can be controlled by regulating the intensities of electric and magnetic fields. This property can keep the bending and buckling stability of the nanoplate exposed to severe thermal and high-speed moving loads. [ABSTRACT FROM AUTHOR]