Abstract
Two series of FEM analyses have been carried out. Firstly, the optimum values of internal friction angle and dilatancy angle, used in the Drucker-Prager type of plasticity model with the strain softening effect, have been discussed for a single concrete element subjected to uniformly distributed lateral pressure. As a result, following values have been obtained. Internal friction angle: 53 degrees, dilatancy angle: e.g. 40 degrees for uniform lateral pressure of 1 MPa, and 30 degrees for 2 MPa. Secondly, simulation analyses have been carried out for the compressive behavior of cylindrical concrete specimens confined by steel tubes or reinforcing bars, introducing interface element. As a result, it has been pointed out that the distribution of equivalent confining pressure along the longitudinal direction of a specimen and the progress of the degree of damage in horizontal sections differ by element types applied to the confining steel and interface elements.
