Question 17.7: Consider an elastic design spectrum, 84.1% for ground motion......

Structural Dynamics of Earthquake Engineering: Theory and Application Using Mathematica and Matlab [1014074]

Consider an elastic design spectrum, 84.1% for ground motion $\ddot{u}_{g0}=1\,g; \dot{u}_{g0} = 121.92~ cm/s; u_{g0} = 91.44 ~cm$ ; ρ = 5%. Using the program developed it is possible to construct a design spectrum as shown in Fig. 17.23.

fig 17.23

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From Fig. 17.23, we can construct a pseudo-acceleration spectrum in terms of g plotted in log scale in Fig. 17.24 for ground acceleration of 1g and damping factor 5%. Similarly for various values of ρ an elastic pseudoacceleration spectrum can be plotted in log scale as shown in Fig. 17.25 and a design spectrum in Fig. 17.26. If pseudo-acceleration is plotted at a normal scale, the diagram is as shown in Fig. 17.26.

fig 17.24

fig 17.25

fig 17.26

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