Free Vibration Analysis of Functionally Graded Nanobeams Based on Different Order Beam Theories Using Ritz Method

This paper presents the fundamental frequency analysis of functionally graded (FG) nanobeams using Ritz method subjected to different sets of boundary conditions. The vibration analysis is based on the classical, the first-order and different higher-order shear deformation beam theories while including rotary inertia. The material properties of FG nanobeams are assumed to vary through the thickness according to the power-law exponent form. Based on the nonlocal constitutive relations of Eringen, the frequencies equations are obtained by the weak forms of the governing differential equations. In this study, the effects of material distribution, nonlocal parameter, beam theories, slenderness ratios and boundary conditions on the fundamental frequency are discussed. The analysis is validated by comparing the obtained results with the available results from the existing literature

Numerical Modeling of an FG Plate Behavior Impacted at Low Velocity in a Temperature Field

This paper analyzes the behavior of a functionnally graded plate subjected to impact force at a low velocity by adopting the Hertz law. The differential equation which governs the impact phenomenon is used to calculate the contact force, indentation and indentation velocity. Elastic properties of the FGM plate are obtained by integration of the components volume fraction across the thickness. A parametric study is conducted to evaluate effects of temperature, the power law index, the projectile mass on the contact force and indentation. The results obtained are compared to those in the literature for other structures

Optimization design based approach for the determination and minimization of the displacement under tensile load in hybrid composite joint

C Composite materials are most often used for lengthier and thin structures susceptible to buckle. The optimization is often carried out taking into consideration the resistance to buckling and tensile loads for minimum displacement i.e maximization of the tensile load for composite assembly joint. It well known that nowadays that composite material in structural mechanics is widely used in many industrial sectors such as in aerospace and aeronautic, automobile, marine  industries as well as in and civil engineering. Composite materials are attractive due to their advantages and performance i.e: lighter weights, high resistance to thermal and mechanical loads, resistance to corrosion and wear. In this paper an investigation is focused on the problem of hybrid assembly joint (bolted –bonded) composite structures. The aim is the optimization of the main influencing parameters. A bonded assembly has only one advantage which is its lightness; on the other hand bolted assembly has the inconvenient of increasing the weight of the structure and stress concentrators. In practice certain structural designs require the use of hybrid assembly for safety and reliability. The objective of this study is to optimize the influencing factors using both Genetic Algorithm and design of experiments for high mechanical performance of hybrid composite assembly

Analyse numérique du comportement biomécanique des implants dentaires

Cette analyse tridimensionnelle s'intéresse à une comparaison par la méthode des éléments finis du comportement biomécanique de l'os mandibulaire pour le cas des dents naturelles et celui des prothèses fixés par des implants dentaires. L'étude consiste à analyser et observer l'intensité des contraintes biomécaniques induites dans l'os mandibulaire (l'os cortical et l'os spongieux) et dans les éléments des prothèses (abutements, implants, couronnes) sous l'effet des efforts masticatoires. Les modèles 3D étudiés sont soumis à un chargement selon les trois directions dans l'espace (corrono- apical, disto-médial, buco-lingual)

Finite Element Analysis of Interactions between two cracks in FGM notched Plate under Mechanical Loading

The investigation of multiple crack interactions in fracture mechanics is important to predict the safety and reliability of structures. This paper introduces a 2D numerical investigation used to calculate the J-integral of the main crack behavior emanating from a semicircular notch and double semicircular notch and its interaction with another crack which may occur in various positions in titanium /titanium boride functionally graded material (TiB/Ti FGM) plate subjected to tensile mechanical load. Youngs modulus of the functionally graded material plate varies along the specimen width (notch radius direction r-FGM) with exponential-law (E-FGM) function. Further, the Poisson蒒s ratio is taken as a constant in normal direction. For this purpose the variations of the material properties are applied at the integration points and at the nodes by implementing a subroutine USDFLD in the ABAQUS software. The variation of the J-integral according to the position, the length, and the angle of rotation of cracks are examined; also the effect of different parameters for double notch FGM plate is investigated as well as the effect of band of FGM within the ceramic plate to reduce J-integral. According to the numerical analysis, all parameters above played an important role in determining the J-integral

Finite Element Analysis of Interactions of between two cracks in FGM notched Plate under Mechanical Loading

The investigation of multiple crack interactions in fracture mechanics is important to predict the safety and reliability of structures. This paper introduces a numerical investigation used to calculate the J-integral of the main crack behaviour emanating from a semicircular notch and double semicircular notch and its interaction with another crack which may occur in various positions in (TiB/Ti) FGM plate subjected to tensile mechanical load. Young’s modulus of the functionally graded material plate varies along the specimen width (notch radius direction r-FGM) with exponential-law (E-FGM) function. Further, the Poisson’s ratio is taken as a constant in normal direction.  For this purpose the variations of the material properties are applied at the integration points and at the nodes by implementing a subroutine USDFLD in the ABAQUS software.  The variation of the J-integral according to the position, the length, and the angle of rotation of cracks is demonstrated. The variation of the J-integral according to the position, the length, and the angle of rotation of cracks are examined; also the effect of different parameters for double notch FGM plate is investigated as well as the effect of band of FGM within the ceramic plate to reduce J-integral. According to the numerical analysis, all parameters above played an important role in determining the J-integral