# The Numerical Determination of Shear Failure Mechanisms in Reinforced-Concrete Beams

*A numerical technique based on the theory of plasticity is presented to predict an upper bound on the collapse load of reinforced concrete beams in shear. The materials are assumed rigid-perfectly plastic. Modified Coulomb failure criteria with tension cut-of are adopted to predict yielding of concrete. A collapse mode is assumed, with rigid moving blocks separated by narrow zones of displacement discontinuity. The shape of yield lines and displacements of concrete rigid blocks are the variables involved in the energy equation. Minimisation of the predicted collapse load produces the optimum shupe of the yield lines. Examples of comparison with other upper-bound analysis and with experiment are given to show the applicability of this numerical technique to a wide range of problems.
A.F. Ashour and C.T. Morley*