29 research outputs found

    JOURNAL OF ORAL REHABILITATION

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    The objective of this study was to calculate stress distribution in a maxillary second premolar tooth which occurred by the mastication force. The tooth model was crowned with Au-Pd alloy, Ni-Cr alloy and porcelain. A load of 450 N, at an angle of 45degrees to the longitudinal axis was applied on the occlusal margin of the crown tooth. The tooth was assumed isotropic, homogenous, elastic and unsymmetrical. This numerical study was carried out using three-dimensional finite element models and calculation programs were prepared by the authors using FORTRAN 77. The distribution of compressive, tensile and shear stress were plotted for the dentine, dentine-metal and metal-porcelain interfaces. The highest stress values were observed when Ni-Cr alloy and porcelain was used

    Calculation of Temperature Distribution on a Crown Tooth by Using Three-Dimensional Finite Element Method

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    The finite element was used to temperature changes with time to Au-AgPd alloy and porcelain crowns in three dimensional models of average maxillary second premolar. Temperature changes some critical nodes were calculated as a result of hot/cold liquid. Calculation programs were prepared by authors using FORTRAN 77. The tooth was assumed isotropic, homogenous, elastic and unsymmetric

    JOURNAL OF REINFORCED PLASTICS AND COMPOSITES

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    The results of a study of elastic-plastic stress analysis and plastic zone propagation in a low density polyethylene thermoplastic composite plate subjected to uniform transverse load are presented. Thermoplastic matrix, polyethylene (LDPE), and steel fibres were used to fabricate the composite plates. Yield points and elastic, elastic-plastic and residual stresses are calculated numerically for both symmetric and antisymmetric laminated plates with different ply orientations by using Finite Element Method. First order shear deformation theory was used as an equivalent single-layer laminate theory for small deformations. Contour plots corresponding to 100, 150 and 200 load steps display the expansion of the plastic zone. Mechanical properties of a layer were obtained experimentally

    Elasto-plastic stress analysis of aluminum metal matrix laminated plates with a circular hole under transverse loading

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    Metal-matrix composites provide new materials with superior properties. They give high strength and stiffness and fatigue properties. In this study, a stainless steel fiber reinforced aluminum metal-matrix laminated simply supported plate with a circular hole is loaded transversely. Elastic, elasto-plastic and residual stresses are calculated in the symmetric and/or antisymmetric cross-ply and angle-ply laminated plate for small deformations by using finite elements method. Load steps are chosen 200, 400 and 600. Isoparametric quadrilateral element with nine node is developed for the elasto-plastic analysis. Metal-matrix composite laminated plate is manufactured by using moulds under the action of 30 MPa and heating up 600degreesC. The first-order shear deformation theory is used in the study

    Elastic-plastic stress analysis and plastic zone propagation in fibre-reinforced thermoplastic laminates using finite element method

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    The results of a study of elastic-plastic stress analysis and plastic zone propagation in a low density polyethylene thermoplastic composite plate subjected to uniform transverse load are presented. Thermoplastic matrix, polyethylene (LDPE), and steel fibres were used to fabricate the composite plates. Yield points and elastic, elastic-plastic and residual stresses are calculated numerically for both symmetric and antisymmetric laminated plates with different ply orientations by using Finite Element Method. First order shear deformation theory was used as an equivalent single-layer laminate theory for small deformations. Contour plots corresponding to 100, 150 and 200 load steps display the expansion of the plastic zone. Mechanical properties of a layer were obtained experimentally

    A calculation of stress distribution in metal-porcelain crowns by using three-dimensional finite element method

    No full text
    The objective of this study was to calculate stress distribution in a maxillary second premolar tooth which occurred by the mastication force. The tooth model was crowned with Au-Pd alloy, Ni-Cr alloy and porcelain. A load of 450 N, at an angle of 45degrees to the longitudinal axis was applied on the occlusal margin of the crown tooth. The tooth was assumed isotropic, homogenous, elastic and unsymmetrical. This numerical study was carried out using three-dimensional finite element models and calculation programs were prepared by the authors using FORTRAN 77. The distribution of compressive, tensile and shear stress were plotted for the dentine, dentine-metal and metal-porcelain interfaces. The highest stress values were observed when Ni-Cr alloy and porcelain was used

    Temperature and thermal stress analysis of a crowned maxillary second premolar tooth using three-dimensional finite element method

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    The purpose of this study was to calculate the temperature and thermal stress distribution as a result of hot/cold liquid in the mouth. This numerical study was carried out using three-dimensional finite element models and the tooth model was crowned with Au-Pd alloy, Ni-Cr alloy and porcelain. In the first part of the study, temperature changes as a result of hot/cold liquid in the mouth were calculated. In the second part, the thermal stresses caused by temperature changes were obtained. The tooth was assumed isotropic, homogenous, elastic and unsymmetrical. The authors using fortran 77 prepared all calculation programs. The distribution of temperature and thermal stress were plotted for some critical points

    An elastic/plastic solution for a thermoplastic composite cantilever beam loading by bending moment

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    In this study, an elastic/plastic stress analysis is carried out for a thermoplastic composite cantilever beam loaded by a bending moment at the free end. The composite beam is reinforced by woven steel fibers, at 0, 15, 30 and 45 degrees orientation angles. An analytical solution is performed for satisfying both the governing differential equation in the plane stress case and boundary conditions for small plastic deformations. The solution is carried out under the assumption of the Bernoulli-Navier hypotheses. It is found that the intensity of the residual stress component of sigma (x) is a maximum at the upper and lower surfaces. The composite material is assumed to be as hardening linearly. The Tsai-Hill theory is used as a yield criterion. (C) 2000 Elsevier Science Ltd. All rights reserved
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