Inelastic behavior of reinforced concrete cantilever beam with embedded steel truss in flexural plastic hinge under cyclic loading

Abstract

Structures are expected to have ductile behavior under major earthquakes. One requirement to achieve this ductile behavior is when the structures have no shear failures in their elements. This paper discusses a new method by using the embedded steel truss in the flexural plastic hinges of beam to avoid shear failure. As already known that the shear strength provided by the concrete will be decreased when the ductility of flexural plastic hinges develop in a member. Therefore, a conservative procedure by ignoring the role of concrete in flexural plastic hinges in resisting the shear demand is adopted by some codes. This will increase the demand for shear reinforcement provided by the stirrup or transverse reinforcement in the plastic hinge; yet it still does not ensure that the shear failure does not come to happen. From the laboratory test results under cyclic loading in this study, it can be noted that the beam with embedded steel truss in the plastic hinge has better hysteretic behavior than the one without the embedded steel truss. The evaluation of test result is also shown the strength of the beam with the embedded steel truss in the plastic hinge is not reduced with an increase in the amplitude of the drift of 1.4 to 3.5. Besides, the strength of the beam without embedded steel truss in the plastic hinge is reduced with an increase in the amplitude of the drift after reaching 2.5.