Abstract (EN):
The need to study and to obtain digital solutions of stochastic nonlinear
differential equations is a common situation in Seismic Engineering. This is
the case for the hysteretic models. These models do not have an exact solution and
can only be approximated by numerical methods. We discretize the solutions using
the stochastic improved Euler scheme and the three parameter implicit stochastic
Newmark schemes: a higher order and a lower order Newmark scheme. In the case
of hysteretic models subjected to gaussian white noises, we were able to reduce the
problem of approximating the solution to that of a linear system in each time step
avoiding the Newton¿Raphson method in the same time steps. This allowed us to
save computational effort in the approximation of the response of the hysteretic
system and was achieved by giving explicitly the value of one of the parameters in
the equation of the Newmark scheme that corresponds to the hysteretic variable
while keeping the equations of the displacement and velocity implicit. We compare
the performance of these two implicit Newmark schemes. In the simulation
study for the Bouc-Wen model, we compare the solutions produced for the specific
choice of the parameters (¿ = 0.5, ß = 0.5) which are the values used by Roy and
Dash(2005) in the case of linear systems. We conclude that the standard deviation
of the displacement obtained from the proposed higher order Newmark scheme is
larger than that obtained from the proposed lower order Newmark scheme. The
proposed lower order Newmark scheme is computationally atractive to compete
with the improved Euler scheme.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
1
License type: