Narjes Bayati - Graduated from Azad University
Mohammadreza Valipour, - faculty member of Azad University
Mohammed Jalali, - faculty member of Azad University

In general, many of the existing buildings need some retrofitting methodsdue to inappropriate conditions at the time of construction, change of use,or design mistakes. In the last few decades, strengthening concrete frameswith new and innovative materials is considered one of the retrofittingtechniques. This is while the behavior of concrete frames covered withCFRP carbon polymer fibers is less well known. In this article, reinforcedconcrete frames with one opening and two floors are modeled andsubjected to lateral displacement as static loading and then under Seismicloading is applied. The main purpose of this article is to investigate andanalyze the effect of crack direction on the fatigue behavior of reinforcingfibers using the finite element method in concrete frames. The results showthat reinforced frames, during both types of loading, have a high stiffnessup to the yield displacement, but after this limit, the lateral resistance ofthis reinforced system suddenly decreases. The comparison of the loadbearingand shear hysteresis curves of the base of the frames shows thatthe fibers with an all-over arrangement play a significant role in increasingthe hardness and finally the lateral resistance of the mentioned framesduring both types of loading. By covering reinforced concrete columns withfibers, the concentration of distribution and the number of plastic strainsand cracks in the columns are reduced, and it is a sign of the properperformance of CFRP fibers in reducing the concentration of distributionand the number of cracks and improving the cyclic lateral behavior of theframes.

strengthening, CFRP fibers, finite elements, dynamic loading