Abstract
This paper examines the free vibration of a cracked nano-beam with non-ideal support, considering thermo -piezoelectric effects through Euler-Bernoulli beam theory and nonlocal strain gradient theory (NSGT). A new approach models crack propagation in nano-beams using torsion springs within the NSGT framework, incorporating thermo-piezoelectric effects. The governing equations, incorporating non-ideal boundary conditions and related effects, are derived using Hamilton's method. The nano-beam is divided into two segments linked by a massless spring, accounting for additional strain energy and the deflection slope discontinuity induced by the crack. This study examines the effects of non-ideal supports, crack position, piezoelectricity, temperature variations, normal stress and strain, and the nonlocal parameter on the system's dynamic behavior. Comparisons with vibrational existing studies reveal strong agreement, emphasizing the significant impact of these parameters on characteristics.
Address
S. Muthulakshmi: Department of Mathematics, Karunya Institute of Technology and Sciences Coimbatore, Tamil Nadu, India
R. Selvamani: Department of Mathematics, Karunya Institute of Technology and Sciences Coimbatore, Tamil Nadu, India
F. Ebrahimi: Mechanical Engineering Department, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran
Abstract
This study investigates the flexural reinforcement of composite box girder bridge decks through combined analytical and numerical approaches using ABAQUS software. The research focuses on deflection, interface stresses, and interfacial slip, while also examining the role of reinforcement type, adhesive properties, and the presence of deck openings. A comprehensive parametric study highlights that material selection, reinforcement configuration, and adhesive characteristics significantly affect structural performance. Moreover, deck openings are shown to increase interfacial stresses and slip due to stress concentration and redistribution.
Key Words
analytical and numerical analysis; composite box girder bridge decks; flexural reinforcement; interfacial slip; interfacial stresses
Address
R. Benferhat, T. Hassaine Daouadji, T. Bensatallah, A. Rabahi: Department of Civil Engineering, Ibn Khaldoun University of Tiaret, Algeria; Laboratory of Geomatics and Sustainable Development LGéo2D, University of Tiaret, Algeria
B. Abbes, F. Abbes: Laboratory Materials and Mechanical Engineering MATIM, University of Reims Cedex 2, France
Abstract
This paper presents a novel parabolic shear deformation plate theory incorporating the stretching effect for bending analysis of simply supported advanced functionally graded plates resting on a Winkler-Pasternak elastic foundation. The theory considers a parabolic distribution of transverse shear strains and satisfies zero traction boundary conditions on the plate surfaces without requiring shear correction factors. This theory involves only five unknowns, fewer than those in other shear and normal deformation theories. The originality of the present work lies in the introduction of a new displacement field based on undetermined integral variables that simultaneously incorporates both shear and stretching effects, providing a more accurate yet simple formulation compared to existing
theories. Material properties are assumed to vary through the thickness direction following a simple power law distribution based on the volume fractions of the constituents. The accuracy of the proposed theory is validated by comparing its results with those available in the literature. The effects of the volume fraction index of the functionally graded material, the side-to-thickness ratio, and the Winkler-Pasternak elastic foundation on the bending responses of functionally graded plates are investigated. The study concludes that the proposed theory is both accurate and straightforward in predicting the bending responses of functionally graded plates, considering the stretching effect on an elastic foundation.
Key Words
analytical modeling; bending; functionally graded (FG) plates; new plate theory; shear and normal deformation; Winkler-Pasternak elastic foundation
Address
Abderrahmane Mouffoki: Laboratoire d'Etude des Structures et de Mécanique des Matériaux, Département de Génie Civil,
Faculté des Sciences et de la Technologie, Université Mustapha Stambouli, Mascara, Algérie
Marc Azab: College of Engineering and Technology, American University of the Middle East, Egaila, 54200, Kuwait
Bessaim Aicha: Laboratoire d'Etude des Structures et de Mécanique des Matériaux, Département de Génie Civil,
Faculté des Sciences et de la Technologie, Université Mustapha Stambouli, Mascara, Algérie; Université de Sciences et la Technologie, BP 15050 Maunaouer, Oran, Algeria
Ali Belhocine: Laboratoire d
Abstract
The analysis of fluid-structure interaction (FSI) in storage tanks is a fundamental aspect of structural design, particularly in spherical tanks used for water storage. Numerical methods implemented in finite element software are commonly employed to address this phenomenon. These methods are typically based on complex formulations that integrate fluid dynamics, providing detailed and accurate results. However, in structural design, engineers often prefer simplified models that adequately capture the essence of the problem without requiring complex simulations. This research aims to validate the modeling approach of FSI in spherical storage tanks using a mechanical-equivalent mass-spring model (MEMSM). The impulsive and convective components of the fluid were represented as lumped masses and springs whose stiffness is associated with the oscillation of the convective component. A perfectly fixed base was assumed, neglecting effects of soil-structure interaction (SSI), to remain consistent with experimental conditions used for validation. The model was validated by comparing the natural vibration frequencies, and the results indicate that the MEMSM model predicts these frequencies with a difference of 1.3% for the impulsive component and a maximum difference of 6.7% for the convective component. This result validates the proposed approach and underscores its main contribution: providing an alternative, efficient, and easily implementable tool for the dynamic analysis of spherical tanks, suitable for early stages of structural design without compromising accuracy.
Key Words
fluid-structure interaction; mass-spring system; numerical model; spherical tank
Address
Lenin P. Montoro and Victor I. Fernandez-Davila: Faculty of Civil Engineering, National University of Engineering, Rímac, Lima 15333, Peru
Abstract
This study pioneers the analysis of low-velocity impact behavior in spinning functionally graded porous circular plates reinforced with graphene platelets (GPLs), employing first-order shear deformation theory. The governing equations are derived via Hamilton's principle, while the plate-impactor interaction is modeled using a modified Hertzian contact law. Numerical solutions are validated against existing literature showing excellent agreement. Parametric studies investigate the effects of:(1) Spinning speed (revealing that higher speeds increase contact force but reduce impact displacement), (2) Porosity characteristics (distribution patterns and coefficients), (3) GPL reinforcement configurations, and (4) Nanofiller weight fractions on the dynamic response. Results highlight that porosity distribution has the most pronounced influence on both contact force evolution and transient centerpoint deflection, outweighing other variables.
Key Words
circular plate; graphene platelets; low-velocity impact; metal foam; spinning motion
Address
Nannan Zhang, Wubin Shan, Qiong Shi: School of Elevator Engineering, Hunan Electrical College of Technology, 411101, Xiangtan, PR China
Huan Li: Changsha Environmental Protection College, Changsha, 410004, PR China
