Título: | DYNAMICS OF SLENDER ONE-DIMENSIONAL STRUCTURES USING COSSERAT CONTINUUM | ||||||||||||||||||||||||||||||||||||||||
Autor: |
FREDY JONEL CORAL ALAMO |
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Colaborador(es): |
HANS INGO WEBER - Orientador |
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Catalogação: | 12/MAR/2007 | 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=9631&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=9631&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.9631 | ||||||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||||||
In this work, it is formulated and analyzed the static
equilibrium
and the dynamics for three dimensional deformation of
elastic rods. The
intrinsically one-dimensional theory that is employed,
which may be called
the special Cosserat theory of rods, is geometrically
exact, namely, it is
not based upon geometrical approximations or mechanical
assumptions.
For the rod deformation, it is adopted the Bernoulli
hypotheses and for
simplicity, the linear constitutive relations are
employed. The deformed
configuration of the rod is described by the displacement
vector of the
deformed centroid curve and an orthonormal moving frame,
rigidly attached
to the cross-section of the rod. The orientation of the
moving frame, relative
to the inertial one, is related by the rotation matrix,
parameterized by
three elemental rotations. In the sense of Cosserat
theory, the equations
of motion are nonlinear partial dfferential equations,
which are functions
of time and one space variable. For the static
equilibrium, however, the
equations become nonlinear ordinary differential equations
with one space
variable, which can be solved approximately using standard
techniques like
the perturbation method. After the static equilibrium
equation are solved,
the displacement functions are obtained. These nonlinear
displacement
functions, which are functions of generic nodal
displacements and rotations,
are used for dynamical analysis. To obtain the dynamics of
the Cosserat
rod, it is used the Lagrangian approach, formed from the
kinetic and
strain energy expressions. Furthermore, the equations of
motion, which
are nonlinear ordinary dfferential equations, are solved
numerically using
the Newmark method. As an application, a curved rod,
constrained to
rotate inside a hole, is investigated numerically and
experimentally. When
using the Cosserat rod approach, that take into account
all the geometric
nonlinearities in the rod, the higher accuracy of the
dynamic responses is
achieved by dividing the system into a few elements, which
is much less
than in the traditional FEM
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