Abstract:
In this dissertation, the effect of mesh quality on stress concentration factor in structural
discontinuities has been investigated. The effect of mesh quality on stress concentration
around the circular holes in an infinite plate subjected to uniform tensile force at the
edges of the plate, which very much conforms to the structural problems faced in
configuring the structures with discontinuity is highly significant. Because structural
discontinuity problems are difficult to solve analytically, a leading general purpose finite
element software NASTRAN-PATRAN has been presented to perform the analyses
computationally. The main purpose of this thesis is to determine how structural
discontinuities alter stress distributions and how the mesh quality influences these
stresses. Different models have been used in this study with variable number and quality
of elements from model to model. Four-node quadrilateral membrane element (2 degrees
of freedom per node) has been used in meshing the computational domain. The mesh
quality has been defined as a combination of two criteria such as element quality and
enough number of elements in the mesh. The quality of the surface mesh should be good
to get acceptable finite element results. Element quality is defined by two factors namely:
Distortion factor and Aspect ratio. Based on these two factors an object oriented C++
program named “MESH QUALITY_2012” has been developed. The results have been
shown in tabular form and graphically. The computed results show good agreement with
the published theoretical results. Finally a correct meshing approach is prescribed to
model structures with single or multiple holes which is essential for a finite element
analyst.
