Abstract
Wear from friction is a major cause of component failure in internal combustion engines, as parts frequently come into contact with each other. Engine oils are used to lubricate these parts and minimize wear. A common approach to reducing friction is to use higher-viscosity oils, which form a thicker protective film between moving components, preventing direct contact. However, while thicker oils can reduce wear, they also increase the energy required to keep the engine running, leading to higher power dissipation. In recent years, the use of nanoparticle-infused lubricants has gained attention for their ability to improve surface properties, enhance heat transfer, boost engine efficiency, and lower maintenance costs. This study explores the effects of adding nanoparticles to engine oils, focusing on their impact on the lubrication and wear resistance of gears and other automotive parts. The results revealed that oils with a higher concentration of nanoparticles significantly reduced the coefficient of friction and wear on stationary discs, confirming the superior lubricating performance of nanoparticle-infused oils. Furthermore, the pressure and anti-wear characteristics of these nano-oils were evaluated, showing marked improvements over conventional oils without nanoparticles.
Address
Dapeng Wang, Bingyin Feng and Xueming Liu: Department of Automotive Engineering, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
Mostafa Habibi: Universidad UTE, Facultad de Arquitectura y Urbanismo, Calle Rumipamba S/N y Bourgeois, Quito, 170147, Ecuador/ Department of Biomaterials, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai, 600 077, India/ Institute of Research and Development, Duy Tan University, Da Nang 550000, Viet Nam
Tayebeh Mahmoudi: Hoonam Sanat Farnak, Engineering and Technology Company, Iran
Abstract
This study aimed to conduct an analysis of the axial free vibration of tapered nanorods based on nonlocal elasticity theory. The small-scale effect on the free axial vibration of a tapered nanorod was studied employing the Adomian decomposition method (ADM) and the finite difference method (FDM) as a checking tool where a contradiction existed between the results of this study and available results in one highly cited work in the literature, which was used for comparison purposes in this work. Different boundary conditions for the nanorod were considered: fixed-fixed nanorod, fixed-free nanorod, and fixed-linear spring nanorod. The governing equation of the problem is a variable coefficient differential equation for which analytical solutions are strictly limited. For this type of problem, analytical approximate methods are effective, and there are many studies available in the literature on the application of these methods to solve linear/nonlinear ordinary/partial differential equations. ADM is one of the methods and was successfully used in this study to analyze the free vibration of nanorods. The results obtained in this study have shown that the presented technique is so powerful and has potential for applications in nanomechanics based on nonlocal elasticity theory.
Abstract
The crack defect is the main problem that occurs in any structure so the effect of crack dimensions on the free vibration of the functionally graded beam (FGB) is studied theoretically and experimentally. This crack is designed as a notch on the top surface of FGB, which is designed based on Euler and Timoshenko beam theories. In this work, FGB consists of five layers in the thickness direction according to the power law model with different percentages of nano Al2O3 and epoxy. Eighteen tensile samples were prepared using a mixture of epoxy Quickmast 105 and nano alumina (Al2O3) at volume fractions of 0%, 1%, 2%, 3%, 4%, and 5%. The experiment aimed to determine the nano alumina volume fraction at which the elastic modulus begins to decrease. Then, this beam is prepared from epoxy and alumina Al2O3 nano with different percentages by hand lay-up method to measure the natural frequency. The effect of nano percentage, power index value, and crack dimensions is studied extensively. The results revealed that at a 5% volume fraction of nano alumina (Al2O3), the elastic modulus increased by 107.12% compared to the pure epoxy sample, while the tensile strength decreased by 16.41% compared to the sample with a 4% volume fraction of nano alumina. Additionally, at a 4% volume fraction, the tensile strength showed an 86.41% increase compared to the pure epoxy sample. Furthermore, when the crack depth ratio and crack position ratio are both 0.5, the natural frequency decreases by 23.30% compared to the intact beam designed with five index values. Finally, the theoretical and experimental results show good agreement, with a maximum difference of 5%.
Key Words
crack; Euler and Timoshenko beam; free vibration; functionally graded beam; mathematical model
Address
Raghad Azeez Neamah and Luay S. Alansari: Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Iraq
Ameen Ahmed Nassar: Department of Mechanical Engineering, College of Engineering, University of Basrah, Iraq
Emad Kadum Njim: Ministry of Industry and Minerals, State Company for Rubber and Tires Industries, Najaf, Iraq
Royal Madan: Department of Mechanical Engineering, Graphic Era (Deemed to be University), Dehradun 248002, Uttarakhand, India
Abstract
This study explores the lateral vibration behavior of bi-directional functionally graded nanobeams using a combination of semi-analytical and machine learning approaches. The semi-analytical method uses the Fourier sine series and Stokes' transform for the deflection function of a bi-directional functionally graded nanobeam constrained by elastic springs at both ends and considers nonlocal modified couple stress theory to account for size effects. In the last step of the method, an eigenvalue problem is derived and the resulting frequency values are then used to train machine learning models, including extreme gradient boosting (XGB), artificial neural networks (ANN) and decision tree regression (DTR). The models' ability to predict the nanobeam's natural frequencies is evaluated using metrics like R2, MAE, MAPE, RMSE, and the A20-index, alongside visual tools such as scatter plots, radar plots, and Taylor diagrams. The results indicate that ML models can accurately predict the natural frequencies of a bi-directional functionally graded nanobeams when provided with sufficient training data. In particular, ANN demonstrated exceptional generalization capability by achieving the highest R2 and the lowest MAE, MAPE, and RMSE on both the training and testing datasets. The impact of various effects on vibration frequencies is detailed through a series of graphs and tables.
Address
Aiman Tariq, Büşra Uzun, Murat Akpinar, Mustafa Özgür Yayli and Babür Deliktaş: Department of Civil Engineering, Artificial Intelligence and Computational Mechanics Laboratory, Bursa Uludag University, Görükle Campus, 16059, Bursa/Turkey
Abstract
Nanotechnology has been integrated into architectural design, and the construction industry is experiencing new solutions that give better structural integrity, aesthetic value, and sustainability for buildings. This paper presents the stability behavior of an artistic design of engineering architectural structure consisting of a honeycomb nanocomposite annular plates reinforced by graphene platelets. A high-order deformation theory is used here for mathematical modeling of artistic design of engineering architectural structure, which can describe the behaviors of these annular plates. Then, a numerical procedure would be introduced to analysis of buckling characteristics of structure. Architectural structures with precisely constituted nanomaterials—carbon nanotubes and graphene derive strength and resilience unprecedented in their ability to withstand environmental stresses and human impacts. The results represent a valuable contribution to the continuing effort of improving our understanding of buckling phenomena in engineering architectural structure and provide a fundamental basis for designing their mechanical behavior, with the aim of enhancement in both geometry and material composition. It is the belief of the paper that in pointing out or highlighting the symbiotic relationship that exists between technology and artistry, it will be in a position to segue the community of architects to be more innovative, experiment with new ideas in the architectural design dimension.
Key Words
annular plates; artistic design of engineering architectural structure; honeycomb nanocomposite; numerical method; stability
Address
Qiang Xu, X. Fee and X. Shen: Department of Culture and Art Management, Honam University, Gwangju,62399, South Korea
A. Yvaz: World-class research center "Advanced Digital Technologies", State Marine Technical University, Saint Petersburg, 190121 Russia
Abstract
The thermo-viscoelasticity of a functionally graded nano graphene platelet reinforced composite (FG-GPLRC) layer is investigated in the present examination. It is presumed that the nanoparticles are uniformly dispersed and arranged in random orientations within an arbitrary point of the one-dimensional domain. In addition, the distribution outline of the GPL volume fraction is based on a power-law model with a controller parameter. The second-order correlation homogenization method is employed to extract the equivalent thermomechanical characteristics of the under-study nanocomposite media. The viscous behavior of the structure is modeled by implementing the Kelvin-Voigt approach. Given that the structure experiences a sudden thermal shock, coupled thermoelasticity is utilized to obtain the governing equations. Moreover, the physical nature of the problem is modified by considering thermoelasticity in the generalized form following the Lord-Shulman (LS) model for the nanocomposite medium. To determine the response of the problem, the Generalized Differential Quadrature (GDQ) and Newmark approaches are applied. Unlike previous studies, which primarily focus on non-viscous or non-LS formulations, our research uniquely applies the LS model to address the thermo-mechanical wave propagation in a viscoelastic nanocomposite layer under thermal shock. This approach allows for more accurate modeling of the thermal responses in such advanced materials. After validating the demonstrated formulation and methods with available studies, multiple parametric cases are presented to thoroughly examine the response of the viscoelastic nanocomposite layer when subjected to rapid heating.
Key Words
FG-GPL nanocomposite reinforces layer; GDQ-Newmark Solution; generalized thermo-viscoelasticity; Lord-Shulman Theory
Address
Yi Yang: School of Civil Engineering Architecture and Environment, Hubei University of Technology, Wuhan 430000, Hubei, China
Chie Zhang: School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Abstract
The investigations report a detailed study of the dynamical behavior and acoustic performance of nanoparticle-enhanced music composition based on porous beams, oriented to make a connection to applications in the design and optimization of musical instruments. In more detail, what is evaluated is how harmonic transverse dynamic loading, combined with structural damping, influences the mechanical and acoustic properties of such advanced structures. Effective properties of the nanocomposite material are computed using Mori-Tanaka's model. These will, in turn, be used to bring out the role of nanoparticles in enhancing the general performance of beams. The nonlinear strain-deflection relationships, energy principles, Hamilton's principle, and derivation of the governing equations for the musical instruments have been explained to ensure a strong theoretical base for the development. A detailed assessment of the dynamic response of the nanoparticle-enhanced musical instruments is conducted, and analysis of their behavior under different conditions is obtained by numerical method. The current study aims to understand the various effects of the key parameters on dynamic and the acoustic properties of musical instruments. Results showed that increasing the volume percentage of the nanoparticles could drastically reduce the acoustic properties by about 71%, hence pointing to a possible improvement in acoustic quality for musical instruments made from these materials. Some very useful ideas, based on the results obtained, occur vis-à-vis how to design an instrument and select materials w.r.t structural integrity and acoustic performance of instruments.
Key Words
dynamic response; music composition, nanoparticles; numerical method; porous beam
Address
Hongyun Zou: College of Art, Hubei Polytechnic University, Huangshi City, 43500, China
Majed Alsubih: Civil Engineering Department, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia
V. K. Bupesh Raja: Department of Mechanical Engineering, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India
N. Beemkumar: Department of Mechanical Engineering, School of Engineering and Technology, JAIN (Deemed to be University), Bangalore, Karnataka, India
Abstract
This paper presents the buckling and post-buckling behavior of a sandwich shell with a lattice polymer core and nanocomposite face layer reinforced with graphene platelets. The rule of mixtures is used to determine the effective mechanical properties of graphene platelet-reinforced surfaces at different distributions along the thickness. The governing deflection equations are derived using high-order shear deformation theory and consider the effects of large deformations with nonlinear von Karman strain-displacement relationships. The elastic foundation is modeled using a two-parameter model developed by Winkler-Pasternak. A closed-form solution method utilizing the Ritz energy approach and Airy stress function is employed for solving nonlinear equations and identifying post-buckling paths under external mechanical forces, including radial compression and axial force. Method validation involves comparison with prior studies' results. The analytical solution explores various parameters, including graphene platelet volume fraction, distribution, lattice core geometric characteristics, and elastic substrate properties, on the buckling and post-buckling behavior of the cylindrical shell. Results indicate that, under axial compression, a moderately long cylindrical shell shows a snap-through equilibrium path after buckling.
