Título: | AUTOMATIC TRACING OF ENVELOPES IN PLANAR STRUCTURES USING A EVOLUTIONARY ALGORITHM | ||||||||||||||||||||||||||||||||||||||||||||
Autor: |
GISELE CRISTINA DA CUNHA HOLTZ |
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Colaborador(es): |
LUIZ FERNANDO CAMPOS RAMOS MARTHA - Orientador LUIZ ELOY VAZ - Coorientador |
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Catalogação: | 21/DEZ/2005 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=7603&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=7603&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.7603 | ||||||||||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||||||||||
The objective of this work is to develop a tool for
obtaining envelopes of
internal forces due to load-trains in the FTOOL software.
Usually, envelopes are
obtained through interpolation of limiting values on pre-
selected sections along
the structure. These values are obtained based on the
positioning of the loadtrain
in relation to influence lines of internal forces. The
determination of limiting
values of an effect at a section represents an
optimization problem whose
objective is to minimize or maximize the values of that
effect in relation to the
position of a load-train that passes along the structure.
However, there is no
analytical expression that defines a limiting value of an
effect on a section for a
specific load-train. Therefore, classical optimization
methods cannot be used to
solve this problem. Rather, the solution requires a method
that does not require
derivatives of the objective function. For this reason,
this work adopts algorithms
of the Evolution Strategy (ES) to achieve the limiting
values due to load-trains.
Two distinct algorithms of the ES, known as ES − + ) 1 (
(lambda) and ES − + ) ( (lambda) (mi) , were
implemented. In addition to the ES algorithms to trace the
envelopes, another
process of solution called Force Brute was developed. It
consists of moving the
load-train in pre-determined steps along the structure and
calculating minimum e
maximum values. In general, the ES method converges to the
correct solution.
However, there are cases, depending on the complexity of
the load-train, that the
algorithms do not find the exact limiting value (although
usually very close to it). It
was observed that the ES results could be complemented and
improved with
results from an inexpensive solution in which concentrated
loads are positioned
on peak values of the influence lines.
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