The effect of moment redistribution on the stability of reinforced concrete moment resisting frame buildings under the ground motion

Document Type : Original Article

Authors

1 MSc of Structural Engineering, Civil Engineering Department, Semnan Branch, Islamic Azad University, Semnan, Iran

2 Associate Professor, Seismic Geotechnical and High Performance Concrete Research Centre, Civil Engineering Department, Semnan Branch, Islamic Azad University, Semnan, Iran

Abstract

In recent years some studies have been done on the moment rredistribution in buildings and new methods offered for calculating of redistribution. Observations demonstrated that the combination of moment and shear force is important in analysis of reinforced concrete structures. But little research is done about the effect of redistribution by using moding in software. In order to study the effect of moment redistribution on the stability of RC moment resisting frame structures, four buildings with 4, 7, 10 and 13 story have been considered. In these models, the nonlinear behavior of elements (beam and column) is considered by the use of interaction PMM hinges. The average plastic rotation was calculated by performing pushover analysis and storing stiffness matrix for 5 points and then the buckling coefficients were obtained by conducting buckling analysis. By the use of modal analysis natural frequency was calculated and it was attempted to be related the average plastic rotation with the buckling coefficients and the natural frequency.   It could be concluded that increase in the plastic rotation reduce the buckling coefficients to about 96% which this amount of reduction is related to the average plastic rotation. Moreover, the buildings experience instability state when the average plastic rotation reached to 0.006 radian.

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References

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Journal of Structural and Construction Engineering
Volume 4, Issue 2 - Serial Number 12
September 2017
Pages 68-84

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History

  • Receive Date: 24 November 2016
  • Revise Date: 25 March 2017
  • Accept Date: 10 April 2017

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