Page 63 - Dynamic Loading and Design of Structures
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Figure 2.14 Maximum values for the DLF in the case of harmonic oscillations.
the harmonic load oscillates too rapidly for the SDOF system to respond. As previously
mentioned, the dynamic response is most intense at resonance.
2.2.3 Elastoplastic systems
When dynamic loads are intense, the restoring force in the SDOF oscillator is no longer linear,
but must be instead written as a generalized function R(y) of the displacement so that non-
linear effects can be described.
We will examine the simple case where the restoring force is linear up until the elastic limit
y is reached, past which it assumes a constant value R . As shown in Figure 2.15, we
m
el
consider a suddenly applied and maintained load F(t)=F ,
1
