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Improved Finite Element Methodology for Integrated Thermal-Structural Analysis
Full text linkAn integrated thermal-structural finite element approach for efficient coupling of thermal and structural analysis is presented. New thermal finite elements which yield exact nodal and element temperatures for one-dimensional linear steady-state heat transfer problems are developed. A nodeless variable formulation is used to establish improved thermal finite elements for one-dimensional nonlinear transient and two-dimensional linear transient heat transfer problems. The thermal finite elements provide detailed temperature distributions without using additional element nodes and permit a common discretization with lower order congruent structural finite elements. The accuracy of the integrated approach is evaluated by comparisons with analytical solutions and conventional finite element thermal-structural analyses for a number of academic and more realistic problems. Results indicate that the approach provides a significant improvement in the accuracy and efficiency of thermal-stress analysis for structures with complex temperature distributions
Adaptive unstructured meshing for thermal stress analysis of built-up structures
Full text linkAn adaptive unstructured meshing technique for mechanical and thermal stress analysis of built-up structures has been developed. A triangular membrane finite element and a new plate bending element are evaluated on a panel with a circular cutout and a frame stiffened panel. The adaptive unstructured meshing technique, without a priori knowledge of the solution to the problem, generates clustered elements only where needed. An improved solution accuracy is obtained at a reduced problem size and analysis computational time as compared to the results produced by the standard finite element procedure
Evaluation of an adaptive unstructured remeshing technique for integrated fluid-thermal-structural analysis
Full text linkAn adaptive unstructured remeshing technique is evaluated for integrated fluid-thermal-structural analysis. The technique is combined with the finite element method to solve: (1) the Navier-Stokes equations for high-speed compressible flow; (2) the energy equation for the structural-thermal response; and (3) the quasi-static equilibrium equations for the structural response. The remeshing technique and the analysis solution procedure are described. The effectiveness of the approach is evaluated with two application studies. The flow analysis of Mach 8 shock-shock interference on a three-inch-diameter cylinder is used as the first application study to demonstrate the capability of the remeshing technique and to examine proper remeshing indicators for the inviscid and boundary layer regions. The applicability of the approach for the thermal and structural analyses of the structure is evaluated in the second application study of a 0.25-inch-diameter convectively cooled leading edge subjected to intense aerodynamic heating. Issues associated with remeshing indicators for thermal stress problems are identified
Adaptive Delaunay triangulation for steady-state and transient heat transfer analyses
No full text245-260A finite element
method is combined with the Delaunay triangulation and the adaptive remeshing
technique to find solutions of both steady-state and transient heat transfer problems.
The Delaunay triangulation and the adaptive remeshing technique are explained
in detail. The solution accuracy and the effectiveness of the combined
procedure are evaluated by heat transfer problems that have exact solutions.
These problems include steady-state heat conduction in a square plate subjected
to a highly localized surface heating, and a transient heat conduction in a long
plate subjected to a moving heat source
Coupled flow, thermal and structural analysis of aerodynamically heated panels
Full text linkA finite element approach to coupling flow, thermal and structural analyses of aerodynamically heated panels is presented. The Navier-Stokes equations for laminar compressible flow are solved together with the energy equation and quasi-static structural equations of the panel. Interactions between the flow, panel heat transfer and deformations are studied for thin stainless steel panels aerodynamically heated by Mach 6.6 flow
A Taylor-Galerkin finite element algorithm for transient nonlinear thermal-structural analysis
Full text linkA Taylor-Galerkin finite element solution algorithm for transient nonlinear thermal-structural analysis of large, complex structural problems subjected to rapidly applied thermal-structural loads is described. The two-step Taylor-Galerkin algorithm is an application of an algorithm recently developed for problems in compressible fluid dynamics. The element integrals that appear in the algorithm can be evaluated in closed form for two and three dimensional elements
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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