Seismosoft | Earthquake Engineering Solutions

Hi!all
I want know input energy 4story RC frame subject ground motion is
input energy= base shear force * top displacement
yes?

bakhtiyar,

It is difficult to see how the suggested measure could accurately reflect the total input energy. If this were true, then the input energy would be the same for a structure subjected to 10 cycles and the same structure subjected to 1000 cycles, as long as the maximum displacement and base shear were equal.

Measures of input energy have been suggested. You might try

"Selection of Artificial Spectrum Compatible Accelerograms for Nonlinear Dynamic Analysis of RC Buildings", Omid Bahar and Abolfazl Taherpour, The 14th World Conference on Earthquake Engineering, 2008.

The referenced paper suggests a method of calculating input energy of accelerograms originally proposed by Fajfar etal, "Seismic design in medium – and long - period Structures", Earthquake Engineering and Structural Dynamics, 18, 1133-1144, 1989.

If you could get your hands on either paper, perhaps you'll find what you need.

tanks
but I want calculate input energy for 4 story frame(bare frame and infill panel frame) under same ground motion. can I use upper formul?

Energy is conserved. The input energy is equal to the output energy (strain energy in the members summed)plus any losses (damping, friction, damage, yielding, . . .).

So the total input energy is a function of the accelerogram history and the mass upon which it acts.

The base shear multiplied by the top displacement has units of energy, but I do not believe it is equal to the entire input energy of the system. (It is for the case of a static load applied at the top).

tanks
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