Each of the
SDOF systems generates a sine wave with a random phase relative to the other
SDOF systems.
The method is intended to be compatible with dynamic
SDOF blast analyses of plate-like structures possessing elastic global response.
The procedure, synthesized in Figure 1(a), evaluates the mechanical characteristics of the dissipative bracing system first for the equivalent
SDOF system and then determines the characteristics of the braces along the building elevation.
Seismic design spectra corresponding to single-degree-of-freedom systems (
SDOFS) are commonly used in structural engineering for the design of multi-degree-of-freedom structures (MDOFS).
[d.sup.*.sub.t]: Target displacement of equivalent
SDOF system
From the perspective of mathematical principles, the classic skyhook control principle is used to control a
SDOF system with one skyhook damper.
The program incorporates four
SDOF curve-fitting algorithms: Peak Picking (PP), Circle Fit (CF), Line Fit (LF) and Direct Modal Estimation (DME) as well as two MDOF algorithms: Frequency Domain Decomposition by Peak Picking (FDD-PP) and its Enhanced version (EFDD).
In the calculation, the load and damping in the equation of motion of the
SDOF system are assumed to be 0.
And twenty-one
SDOF systems are designed according to the DBSD procedure and analyzed to indicate that the proposed equivalent damping relationships are suitable for the DBSD.
In the next step of validation of the FE analysis, maximum blast response of the equivalent single-degree-of-freedom (
SDOF) system of the considered RC beam (without axial force) was calculated using UFC-3-340-02 [19] methodology (Chapters 3 and 4).
Let us consider a
SDOF system subjected to a sudden stiffness reduction under impulse excitation.
where [T.sub.e] is the effective fundamental period of the building in the direction under consideration; [S.sub.a] is the response spectrum acceleration coefficient corresponding to the effective fundamental period; [C.sub.0] accounts for the difference between the roof displacement of an MDOF building and the displacement of the equivalent
SDOF system; [C.sub.1] is the modification factor to account for the difference between the maximum elastic and inelastic displacement amplitudes in structures; [C.sub.2] adjusts design values based on component hysteresis characteristics, stiffness degradation, and strength deterioration.