Banca de DEFESA: JORGE DAVID JOAQUIN APAZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JORGE DAVID JOAQUIN APAZA
DATE: 17/05/2023
TIME: 18:30
LOCAL: CAMPUS DE SANTO ANDRE, REMOTAMENTE
TITLE:

STUDY OF THE DYNAMIC STABILITY OF A CANTILEVER PIPE ASPIRATING INTERNAL FLUID

PAGES: 120
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Mecânica dos Sólidos
SPECIALTY: Dinâmica dos Corpos Rígidos, Elásticos e Plásticos
SUMMARY:

This dissertation aims to analyze the dynamic stability of a flexible cantilever pipe in a
vertical configuration, with internal fluid aspiration at its free end. A mathematical model is
reviewed, considering simplifying assumptions; the pipe-fluid system behaves as a cantilever
beam tensed (following Euler-Bernoulli theory) combined with an internally flowing piston
model. The resulting equations of motion are derived and linearized around the equilibrium
configuration using the Newtonian analytical approach, based on the balance of forces and
moments. The differential equation describing the motion is discretized using the Galerkin
method, resulting in a set of second-order ordinary differential equations. These equations are
expressed in matrix form, considering that the fluid velocity is gradually increased, and the
complex natural frequencies are numerically solved with each velocity increase. The Argand
diagram is then presented to identify the critical velocity at which the system becomes unstable.
The results show that the onset of instability occurs at the first frequency associated with the
first mode at very low fluid velocities. Finally, the sensitivity analysis of the viscoelastic
coefficient of the pipe material is presented, indicating that this coefficient has a delaying effect
on the onset of system instability. As a result, the first critical velocity of the system is increased,
regardless of the fluid used (oil, water, air).

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1761050 - JUAN PABLO JULCA AVILA
Membro Titular - Examinador(a) Interno ao Programa - 1604343 - KARL PETER BURR
Membro Titular - Examinador(a) Externo à Instituição - JOSEPH ARTHUR MELENDEZ VASQUEZ
Membro Suplente - Examinador(a) Interno ao Programa - 2249350 - DIEGO PAOLO FERRUZZO CORREA