Constitutive modeling of concrete is the core for the nonlinear analysis of concrete structures. In this work, a new triaxial nonlinear material model, called model M4L was developed within the microplane framework. Numerical experiments indicate that model M4L is able to provide satisfactory descriptions of the inelastic behavior of concrete subjected to various loading conditions, such as tension, compression and shear as well as their different combinations.
After extensive validations against the test data at the material level, the new model was implemented in a finite element package and used to predict the behavior of various concrete structural components and systems. It was found that the model reproductions are in good agreements with the experimental observations. In addition, some successful applications to industrial complex concrete structures were also presented.