Graphical modeling of discontinuous stress field for RC deep beams under uniform load

摘要

The fanning compression stress pattern in RC deep beams under uniform loadpresents a challenge to formulating the configuration of strut-and-tie model(STM). To this end, this paper proposes an alternative method for creating agraphical discontinuous stress field model (DSFM) to fill up the whole beamcontinuum. It comprises a certain number of trapezoidal stress-bands withvarying bandwidths, and their stress values can be calculated based on forceequilibrium conditions. Several stress subfields are defined through a certainstress combination from several directions. The DSFM is implementable forboth service limit state (SLS) and ultimate limit state (ULS) in that its configurationis primarily oriented by elastic stress field and only a limited plasticredistribution is allowed for plastic failure. The graphical procedure of DSFMis demonstrated and examined by a test deep beam example, which shows thatthe predictions are fairly in good agreement with the test results.