Title: Rotation Compatibility in the Limit Design of Reinforced Concrete Continuous Beams

Author(s): M. Z. Cohn

Publication: Symposium Paper

Volume: 12

Issue:

Appears on pages(s): 359-382

Keywords:

DOI: 10.14359/16724

Date: 1/1/1965

Abstract:
The object of the paper is to provide a simple, rational technique to check the rotation compatibility of plastic hinges in limit designed reinforced concrete continuous beams proportioned basing on optimum considerations. The relationship between the plastic adaptability and the rotation compatibility is outlined, expressing conveniently both the inelastic rotations and the rotation capacities of critical sections. It is concluded that the compatibility requirement implies only limited adaptability tobe used in the design of concrete structures. Since a similar conclusion can be derived with regard to the serviceability conditions of limit designed structures, adoption of convenient upper bounds for the redistribution factors (or lower bounds for the yield safety parameters) of critical sections will implicitly provide adequate solutions for ultimate safety, compatibility, and serviceability as well. From the practical viewpoint, the significant result follows that for given ( 1) properties of materials, (2) loading conditions, and (3) amount of accepted redistribution, the rotationcompatibility condition to an upper limitation of the steel percentages at critical sections.