Abstract
The tension softening diagram provides valuable informations to discuss the fracture behavior of concrete. In this paper, the numerical analysis method to calculate the poly-linear tension softeing diagram is investigated. The prediction method for the load-displacement relationships of concrete with cracks is developed by using the fictitious crack model concept with the K-superposition method and the constitutive law by the poly-linear tension softening diagram. In this method, nonlinear crack equations are solved by the iteration program of evaluating the softening inclinations. Poly-linear approximation method for calculating the softening diagram from the actual load-displacement curve is proposed based on the crack equation analysis method. The softening diagrams of concretes with various aggregates and matrix strengths are measured and their characteristics are'discussed.
