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Dissimilar Materials (dissimilar + material)

Distribution by Scientific Domains
Engineering60%
Polymers and Materials Science40%

Selected Abstracts

Numerical evaluation of eigenvalues in notch problems using a region searching method

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2006
Y. Z. Chen
Abstract This paper presents a method for finding the eigenvalues of some equations, or the zeros of analytic functions. There are two steps in the method. In the first step, integration along the edges of rectangle for an analytic function is performed. From the result of integration, one can know whether the zero exists in the rectangle or not. If the zero of an analytic function exists in the rectangle, we can perform the second step. In the second step, the zero is obtained by iteration. Therefore, the method is called a region searching method. Particular advantage of the suggested method is that the process for finding zero can be visualized. For example, one can clearly indicate the rectangles, which contain the zeros of an analytic function. Three numerical examples are presented. The obtained results are satisfactory even for a complicated case, for example, for finding eigenvalues of a composed wedge of dissimilar materials. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Transient heat conduction analysis in a piecewise homogeneous domain by a coupled boundary and finite element method

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2003
I. Guven
Abstract A coupled finite element,boundary element analysis method for the solution of transient two-dimensional heat conduction equations involving dissimilar materials and geometric discontinuities is developed. Along the interfaces between different material regions of the domain, temperature continuity and energy balance are enforced directly. Also, a special algorithm is implemented in the boundary element method (BEM) to treat the existence of corners of arbitrary angles along the boundary of the domain. Unknown interface fluxes are expressed in terms of unknown interface temperatures by using the boundary element method for each material region of the domain. Energy balance and temperature continuity are used for the solution of unknown interface temperatures leading to a complete set of boundary conditions in each region, thus allowing the solution of the remaining unknown boundary quantities. The concepts developed for the BEM formulation of a domain with dissimilar regions is employed in the finite element,boundary element coupling procedure. Along the common boundaries of FEM,BEM regions, fluxes from specific BEM regions are expressed in terms of common boundary (interface) temperatures, then integrated and lumped at the nodal points of the common FEM,BEM boundary so that they are treated as boundary conditions in the analysis of finite element method (FEM) regions along the common FEM,BEM boundary. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Thermoelastic stress field in a piecewise homogeneous domain under non-uniform temperature using a coupled boundary and finite element method

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2003
I. Guven
Abstract This study concerns the development of a coupled finite element,boundary element analysis method for the solution of thermoelastic stresses in a domain composed of dissimilar materials with geometric discontinuities. The continuity of displacement and traction components is enforced directly along the interfaces between different material regions of the domain. The presence of material and geometric discontinuities are included in the formulation explicitly. The unknown interface traction components are expressed in terms of unknown interface displacement components by using the boundary element method for each material region of the domain. Enforcing the continuity conditions leads to a final system of equations containing unknown interface displacement components only. With the solution of interface displacement components, each region has a complete set of boundary conditions, thus leading to the solution of the remaining unknown boundary quantities. The concepts developed for the BEM formulation of a domain with dissimilar regions is employed in the finite element,boundary element coupling procedure. Along the common boundaries of FEM,BEM regions, stresses from specific BEM regions are first expressed in terms of interface displacements, then integrated and lumped at the nodal points of the common FEM,BEM boundary so that they are treated as boundary conditions in the analysis of FEM regions along the common FEM,BEM boundary. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Rapid, Room-Temperature Formation of Crystalline Calcium Molybdate Phosphor Microparticles via Peptide - Induced Precipitation,

ADVANCED MATERIALS, Issue 13 2006
G. Ahmad
A phage display method has been used for the first time to identify peptides that bind to, and induce the rapid formation of, a pure crystalline binary metal oxide compound, CaMoO4, at room temperature from a soluble aqueous precursor solution (see figure). This demonstration opens the door to the biosculpting (peptide patterning, then localized peptide-induced mineralization) of functional synthetic crystalline multicomponent compounds onto or with low-temperature or chemically dissimilar materials. [source]

Modeling of Thermal Stresses in Joining Two Layers with Multi- and Graded Interlayers

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2006
C. H. Hsueh
The technique of introducing interlayers has been used extensively to mitigate residual thermal stresses in joining dissimilar materials. Finite-element analyses have often been used to quantify thermal stresses in these layered structures in case-by-case studies. Recently, simple analytical models containing only three unknowns have been developed to derive closed-form solutions for elastic thermal stresses in both multilayer systems and two layers joined by a graded junction. The analytical solutions are exact for locations away from the free edges of the system. Application of these solutions is shown here to provide a systematic study of thermal stresses in Si3N4 and Al2O3 layers joined by various sialon polytypoid-based multi- and graded interlayers. The effects of the thickness, stiffness, and coefficient of thermal expansion of the interlayer on thermal stresses in the system are examined. The differences in thermal stresses resulting from multi- and graded interlayers are shown. [source]