Browsing by Author "MEDDOUR Belkacem"

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Numerical Modeling of the Effects of Fiber Packing and Reinforcement Volume Ratio on the Transverse Elasticity Modulus of a Unidirectional Composite Material Glass / Epoxy
    (Revue des Composites et des Matériaux Avancés-Journal of Composite and Advanced Materials, 2020-12-06) BREK Samir; MEDDOUR Belkacem
    Composite materials are very widely used in the manufacturing of structures because of their specific mechanical properties. However, they are characterized by heterogeneity and anisotropy and they present great challenges in designing and also in predicting their behavior by using the numerical simulation. The unidirectional composite material has a more relevant property which is the transverse elasticity modulus E2. The determination of E2 is still interesting researchers because of the diversity of results obtained by several models and approaches. This study aims to predict the transverse elasticity modulus E2 of a unidirectional Glass/Epoxy composite material, the effect of the arrangement fibers on the transverse elasticity modulus and predict the values of the reinforcement factorξ used in the Halpin-Tsai model. To do so first we adopted the micromechanical approach, which is accurate but requires much computing, and we used a calculation code based on FEM method and considered two parameters to vary, which are the volume fraction of fibers and the distribution of fibers. The obtained results of numerical modeling were tightly compared to those obtained by the available analytical models and the adopted approach can be used to predict the transverse elasticity modulus E2 and the reinforcement factor ξ.
  • No Thumbnail Available
    Item
    Numerical Study of the Behavior of a Zirconia Dental Prosthesis with Prior Defect
    (2017) MEDDOUR Belkacem
    The biomechanics field continues with its progress and will not cease to grow due to ongoing research in this area to find better solutions to problems. It is in this context that this work aims to simulate the mechanical behavior of a dental prosthesis made from zirconia. The proposal of zirconia as a material for dental prosthesis is the main aim of this paper. Indeed, Zirconia as a bioceramic material presents many advantages, and especially good biocompatibility and high resistance of wear. On the other hand the disadvantage of this material is its fragility i.e. it has weak strength against cracking. So, in this paper we considered a dental prosthesis assumed to be implanted to an adult person. In order to study the crack initiation we considered a defect in this prosthesis. Using the conditions of blocking and loading by Abaqus simulating tool, we obtained the results revealing the possibility of using zirconia as a material for dental prosthesis.
  • No Thumbnail Available
    Item
    One dimensional modeling of the thermoelastic behavior of shape memory alloys
    (AFM, EDP Sciences 2015, 2014-05-20) MEDDOUR Belkacem
  • No Thumbnail Available
    Item
    Simulation of the Behavior of a Cracked Head of Shoulder Prosthesis
    (JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2020-12-25) MEDDOUR Belkacem
    The health safety of the human being is one of the most important goals of governments around the world. The cessation of the functioning of any organ of the human body would have a negative impact on psychological and physical health of the patient. The replacement of the damaged organ by an artificial organ is the used solution. The shoulder joint is an example; a total prosthesis can be implanted to recover the functioning of the upper limb. The right choice of materials for this prosthesis is one of the research directions today. The purpose of this work is to predict the propagation of the crack previously created in the head of the shoulder prosthesis. Shoulder prosthesis is composed of two components: a head made usually of inoxydable steel or metallic alloys and a cup which could be made of UHMWPE. The proposed material of the head was alumina. As bioceramics, alumina has known properties that make it a candidate material to replace used stainless steel or metallic alloys. But fragility is the most undesirable alumina property. So to investigate its tenacity prior defects were created and to extend the investigation two cases of remarkable location of the prior crack were considered. The selected mean of simulation is the finite element calculation code Abaqus. The needed data: geometries of the two compounds of the shoulder prosthesis, loads and mechanical properties of the considered material were implemented. The obtained results concerned normal stresses at the tip and the line of propagation of prior cracks. The calculation of intensity stress factor is necessary to judge alumina tenacity. Final results in the two cases reveal the possibility of using alumina as a material of the humeral insert.
  • No Thumbnail Available
    Item
    Three Dimensional Modeling and a Simulation of the Shape Memory Effect
    (Scientific Technical Review, 2014) MEDDOUR Belkacem
    The paper deals with modeling and simulating the shape memory effect , one of many behaviors of shape memory alloys. The effect was first divided into three stages. Every stage has its own thermodynamic potential and constitutive equations. The martensite fraction is the only internal variable to be considered: in the first stage, it represents the fraction of detwinned martensite; in the second stage, it represents the fraction of transformed martensite into austenite, and in the last stage, it represents the fraction of the produced martensite from the austenite transformation. For every stage, we deduced the constitutive equations using the principles of thermodynamics and a simple formalism. When the model was defined, we simulated it using the experimental data obtained by analyzing a cube specimen subjected to triaxial traction and thermal load. The obtained results of this simulation reflect the behavior of this kind of materials when thermomechanical load is applied. The main finding of this paper is that the proposed constitutive model can be used to simulate the shape memory effect.
  • No Thumbnail Available
    Item
    Three-dimensional modeling of pseudoelastic effect of the shape memory alloys
    (2015) MEDDOUR Belkacem
    The present work aims to develop a 3D constitutive model to describe pseudoelastic effect on the behavior of memory shape alloys. This phenomenological constitutive model is based on a set of variables: temperature and stress as control variables, and the fraction of the martensite as an internal variable. By using the first and the second principle of thermodynamics and with a simple formalism, we have developed constitutive equations followed by criteria of transformations. This developed model has parameters intended to be determined by a tensile pseudoelastic test. We have introduced an algorithm to simulate the response of the model with respect to experimental data. Three cases were considered: one dimensional, biaxial and triaxial loading.