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This paper proposes a closed analytical
integration of BEMs integrals
in the contex of plane elasticity.
Our BEMs formulation is based
on subparametric interpolation and
problems geometry is discretized
by straight elements with three
nodes in the global coordinates
system. Each element is transformed
to a local dimensionless system,
which uses a quadratic formulation.
On this dimensionless system closed
expressions for BEMs integrals
were developed by evaluating them
with a Computer Algebra Systems
(CAS). Quasi singular and singular
integrals were addressed in our
formulation and the analytical expression
for them are able to deal with very
strong quasi-singular situations
(source point is very close to the
integration element) and with cases
when source point belongs to the
element (singular integration).
All those closed analytic expressions
were optimized and implemented in
a BEM code in substitution of numerical
integration. This allows us to avoid
expensive and repetitive calculations.
A comparative study shows savings
of 4000 % in CPU times for a BEM
code based on analytical integration.
Moreover, approximated solutions
obtained by the BEM with analytic
integration were more accurate than
those produced by standard BEM codes.
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