Biomechanics
Diana Martins; Rui Couto; Elza M M Fonseca; Ana Rita Carreiras
Abstract
This work presents a numerical approach to predict the influence of material stiffness in a dental implant using different thread profile shapes, always with a constant number of threads, thread width and thread pitch. Dental implant affects bone tissue, in response to various mechanical stimuli where ...
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This work presents a numerical approach to predict the influence of material stiffness in a dental implant using different thread profile shapes, always with a constant number of threads, thread width and thread pitch. Dental implant affects bone tissue, in response to various mechanical stimuli where the biomechanical behavior plays a significant role in the study of stress and strain calculation. In this work, four different thread profile shapes were considered (Model1 - Plateau typeA, Model2 - Plateau typeB, Model3 - Triangular, Model4 - Rectangular) with two different inner diameters equal to 4 and 6 mm, using three different implant materials (titanium, an iso-elastic titanium and zirconium alloys). Two dimensional computational axisymmetric models of a bone-implant were constructed using the finite element method. This study presents the numerical results about the mechanical stimuli on dental implant according to the chosen material and profile shape. The main contribution of this work is giving additional information about the stability and implant loosening with the application on surgical techniques in dental science.
Vibration
Mellel Nacim; Ouali Mohammed; Dougdag Mourad; Mohammedi Brahim
Abstract
This paper presents an extended cross modal strain energy change method to estimate the severity of damage associated with limited modal data in beam-like structures. This method takes in account the correlation between the analytical modal data and the measured incomplete modal data. A procedure ...
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This paper presents an extended cross modal strain energy change method to estimate the severity of damage associated with limited modal data in beam-like structures. This method takes in account the correlation between the analytical modal data and the measured incomplete modal data. A procedure was proposed and the analytical elemental stiffness of the damaged element after it is localized is included in quantification of the measured single damage extent. A three-dimensional numerical beam model with different damage cases is used to simulate the CMSE method application and to getting the bending displacements of the damaged element. An experimental modal analysis (EMA) on a cantilever beam with and without crack was carried out to evaluate the effectiveness of the extended CMSE method. The severity magnitude of the damage was predicted within an acceptable error range through the using validation process. Results reveal that the proposed damage estimation method successfully evaluates single damage severity in beam like structure and can be useful in maintenance technology and structural health monitoring system.
Heat and Mass Transfer
M. Rahimi; M. Mortazaei
Abstract
Jet impingement heat transfer is an effective and practical approach that is employed in many industrial processes where heating, cooling, or drying is required. Details of the heat or mass transfer rate have been investigated both experimentally and numerically and can be found in the published literature. ...
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Jet impingement heat transfer is an effective and practical approach that is employed in many industrial processes where heating, cooling, or drying is required. Details of the heat or mass transfer rate have been investigated both experimentally and numerically and can be found in the published literature. In most of the numerical studies, control-volume approach has been employed to solve the governing equations of the thermal and flow fields. Using this numerical approach, a pressure correction equation is usually developed from the conservation equations in a rigorous manner to obtain the pressure distribution. Avoiding the complexities encountered in the traditional manner, a full implicit finite-difference method was developed for the first time and applied for studying jet impingement heat transfer. Similar to the velocity components, static pressure was also treated as an unknown variable in this approach. Specifications of both flow and thermal fields were obtained for two cases of confined and unconfined jets by the proposed numerical method. It was demonstrated that this novel numerical approach was a straightforward method, which required no additional equation for pressure calculation, and had the potential use in other two- or three-dimensional flow and thermal field analysis.
