Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2007.3524.3529Najim MahmoodMohammad122007722A nonlinear finite element analysis is conducted using ANSYS-V10 finite element package on six reinforced concrete cantilever beams having different length vary from 0.5 to 3 m with 0.5 m increments and subjected to a concentrated torque at the free end. The beams are designed to carry the same torque. The study emphasize on the effect of beam length (span to depth ratio) on the torsional strength and behavior of reinforced concrete rectangular beams and the effectiveness of the torsional reinforcement in the pre and post cracking stages of loading. It was found that beams with span/depth ratio equal to or more than 4 have the same reserved torsional strength and less than those with smaller ratio, keeping the cross section and torsional reinforcements constant for all the beams. Before cracking stresses in transverse and longitudinal reinforcement are almost negligible and it is far below the yield stress even at the post cracking stages. Reinforcement attained yielding only at ultimate torque and after the wide spread of cracks in the shorter beam.]]>ACI 318-05 and Commentary,2005ANSYS-V10,2005Aryal, M.P.,2005Desayi, P. and S. Krishnan,1964Fang, I.K. and J.K. Shiau,2004Hao-Jan, C., I.K. Fang, W.T. Young and J.K. Shiau,2007Hsu, T.T.C.,1968Mac-Gregor, J.G.,1992Rahal, K.N.,2000Willam, K.J. and E.D. Warnke,1975William, K. and T.A. Tanabe,2001