Using XFEM technique to predict the damage of unidirectional CFRP composite notched under tensile load

The composite materials are widely used in aircraft structures. Their relative rigidity/weight gives them an important advantage over the metal structures. The objective of this work is to analyze by the finite element method the mechanical behavior of composite plate type notched with various forms under tensile load. Two basic parameters were taken into consideration. The first, the form of the notch in order to see its effect on the stress and the failure load. The second, we studied the influence of the locale orientation of fiber around the plate's notch. These parameters are studied in order to see their effects on the distribution stress and failure load of the plate. The calculation of the failure load is determined numerically with the numerical code ABAQUS using the XFEM (extended Finite Element Modeling) based on the fracture mechanics. The result shows clearly that it is important to optimize the effect of fiber orientation around the notch

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 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

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

Effects of the Geometric Parameters on the Interfacial Stresses Bone/Implant

Implantology is the fixation of an artificial root made of titanium in the mandibular bone, emerging from the gum and supporting atooth or prosthetic element. In this work, the mechanical behavior of dental implants with different geometric shapes is analyzednumerically by the finite element method. The first objective of this study is to show the importance of the geometric parameters suchas length on the variation of the equivalent stress in the close vicinity of the bone / implant interface. These interfacial stresses areevaluated on the outside and inside of the net. The results clearly show that the best model of the implant obtained is that of 10.43 mmin length. The second objective is focused on the distribution of von Mises stress in the bone and the dental implant in different loadingcases. It is important to know the effects of this type of treatment to obtain a primary stabilization of the structure or at the interfacebone/implant