Abstract
In the conventional design of a building, only static analysis in the horizontal
and uniaxial directions is commonly carried out, in order to minimize calculation
costs. This approach may ensure the structural strength of the building,
if there is sufficient strength to support the load in vertical direction.
However, the mass system model replaces the building layer in dynamic analysis,
and the complicated dynamic behavior of the structure at member level is
not sufficiently examined. Therefore, the development of a more precise
and more efficient dynamic analysis code is strongly desired. Recently,
significant advances in the field of computers have been removing the calculation
cost restrictions, and various dynamic analysis codes are being developed.
In this study, the Adaptively Shifted Integration (ASI) technique with
a linear Timoshenko beam element, which can express a plastic hinge located
at an exact position by shifting the numerical integration point in the
element, is implemented into the finite element code in order to develop
a more precise and less calculation-time-consuming seismic response analytical
tool.
The purpose of this study is to verify the validity of the ASI technique
in seismic response analysis and to construct a highly efficient structural
design tool for RC structures. Analyses considering vertical seismic excitation
or the phase difference of seismic-wave propagation, and those involving
structural discontinuities such as member fracture are carried out as numerical
examples. Member fracture can be expressed by forming a plastic hinge located
at an exact position with a simultaneous release of the resultant forces
in the element. A contact algorithm is added to the code to reproduce phenomena
such as intermediate-layer failure. The results reveal that this technique
can be used in the numerical estimation of structural reliabilities.