كليدواژه :
Deterioration Behavior , Special Concrete Moment Resisting Frame , Target Displacement , shear wall , Nonlinear static analysis
چكيده فارسي :
One of the shortages of pushover analysis is that it approximately considers the effects of deterioration
pertained to hysteretic loops for structural elements. To evaluate this effect, it is necessary to perform
nonlinear static and dynamic analyses and compare the results. To this end, six different planar frames, each
one being a part of three-dimensional designed structures, have been modeled in OPENSEES software. All
of the structures are the same in plan and different in height. Deterioration behavior as well as non-degrading
behavior is considered in time history analyses. Also twelve ground motion records which are scaled to
0.35g hazard level have been used. For modeling the structural elements, stresses and strains for each
designed section are considered with respect to confinement effects. The required backbone curve includes
cracking, yielding and ultimate stress points which are all derived from USC-RC software, and of course
with considering elements cross section, arrangement, number and size of reinforcing bars. For accurate
calculation of the target displacement and bilinear idealization of capacity curve, a computer program was
developed in MATLAB environment to determine the target displacement, strength ratio (R) and etc.
Finally maximum displacement amounts derived from inelastic dynamic analyses for 0.35g hazard level are
compared with those obtained from nonlinear static analyses. Results show that with increasing the height of
frame, the variance between frame displacements with both deteriorating and non-degrading behavior will be
decreased, so that the effect of deterioration behavior could be neglected in target displacement calculation
for high-rise frames.
