MODIFIED SOFTENED STRUT-AND-TIE MODEL FOR RC EXTERIOR BEAM–COLUMN JOINTS

摘要

Reinforced concrete(RC)exterior beam-column joints are vulnerable to brittle shear failure during an earthquake.A modified softened strut-and-tie model(MSST)for determining the shear strength of RC exterior beam-column joints is proposed in this paper.It is a simplified analytical model,in which the contribution of the shear reinforcement is taken into account through the nominal tensile strength of concrete.And,the concrete softening effect of the strut is taken into account utilizing the Kupfer-Gerstle biaxial tension-compression failure criterion,based on which a formula for shear strength prediction is derived.The MSST is evaluated using 59 existing test results,and the results demonstrate its accuracy.It can be concluded that the MSST can be employed in the practical design due to its simple form,wide applicability and accuracy.