D. CAPRITA
Institutul de Cercetari si Ingineria Mediului, Bucuresti
MATHEMATICAL MODELLING OF THE ISOMETRIC STRUCTURES
IN THE DC ELECTROMETRIC PROSPECTION
(Abstract)
Geophysical interpretation relies on knowledge of the anomalies caused by
specific structures. For electrical methods, the calculation of such anomalies
by numerical techniques has particular importance because of the limitations
of analytic methods and the inconveniences of laboratory modeling.
This paper describes the application of the finite element method to the calculation
of electric potential distribution of a buried spherical body. Beforehand,
the potentials computed with finite element method in a homogeneous medium
have been compared with the theoretical values, in order to point out the significant
errors in results.
Application of the finite element method to the solution of physical problems
is based on minimization of energy; in the present case electric energy is
minimized.
At the same time the direct calculation algorithm of abnormal potential was
presented and the methodology accuracy compared to analytical solution was
tested.
The finite element method can be applied successfully to various geophysical
problems. As the underlying principle – energy minimization – is
general, it is simple to set up the method for direct current, electromagnetic,
or magnetostatic situations. The method promises to be especially suitable
for modeling irregularly shaped structures with several variations of physical
properties.
Key words: Resistivity 3-D numerical modeling, finite element method, special
body, isomerical bodies.