INVESTIGATION THE PUNCHING SHEAR BEHAVIOR OF REINFORCED CONCRETE SLAB-COLUMN CONNECTION USING CARBON FIBER REINFORCED POLYMERS
Volume 8, Issue 1, Winter 2015, Pages 38-58
Ali Hameed Naser Al-Mamoori
Abstract The region of a slab in the vicinity of a support could fail in shear by developing a failure surface in the form a truncated cone or pyramid. This type of failure, called "Punching Shear Failure", is usually the source of collapse of flat-plate and flat-slab structures. An experiment to be conducting to investigate the punching shear strength and failure behavior of self concrete (SCC) slabs using carbon fiber reinforced polymer (CFRP) bars as internal strengthening in connection region for slab-column. Seven interior slab-column connections tested including same concrete compressive strength and ratio of the reinforcement. All slabs will be tested as a simply supported and subjected to punching loading by interior column. Test results show that the internal strengthening technique by using high tensile strength CFRP bars improves the bearing capacity of RC two-way slabs. Based on the experimental results, it is possible to increase punching shear capacity by using internally reinforced with CFRP bars concentrated in slab-column zone, this increase is about (33-100%) compared with the unstrengthened (control) slab. The effectiveness of the CFRP bars is depended substantially on distributed or arrangement manner in slab-column region. Also, it is found that, the use of NSM CFRP bars is an effective technique to enhance shear capacity of SCC slab-column models and nearly provided the same efficiency of internal reinforcement. Even efficient to increase the punching shear load, the top reinforcement of CFRP bars will not change the brittle-type punching shear failure mode compared with bottom CFRP bars reinforcement.
THREE DIMENSIONAL FINITE ELEMENT SIMULATION OF COLD FLAT ROLLING
Volume 4, Issue 1, Winter 2011, Pages 502-515
Hassanein Ibraheem Khalaf, Dr. Abdul Kareem Flaih Hassan
Abstract In this paper the finite element analysis of the cold flat rolling is well presented to predict the roll force, slab velocity at entry and exit, temperature rise in the slab during cold rolling, strain and stress distribution around the slab. The effects of friction coefficient and yield stress of slab material on rolling are assumed. It is found that maximum force occurs at the position of neutral point between entry and exit, also it is found that the velocity of slab at exit is larger than that at entry. The finite element results of temperature distribution around the slab predict that there is a considerable rise in slab temperature.