Abstract
This paper presents static and high-speed tri-axial compression fracture analysis of concrete specimen by using a mixed RBSM (rigid body spring model)-FEM model. A new RBSM model proposed here in has 3 couples of spring normal to and parallel to the failure plane located at the center of the element with an arbitrary angle, and 4 nodes at the out side comer of the element so that this element an be installed in the FEM platform without any interface. This model can take into account the bilinear elastic plastic gap behavior and Mohr-Coulomb slip behavior including softening in elastic plastic behavior. After formulating the basic equation of this model test piece compression test results that include the localization and softening behavior is simulated by using the proposed model. It is found that the proposed method can express very well the softening curve and residual resistance induced by localized fracture plane. Furthermore, the high-speed loading test results are simulated by the proposed method. It is also found that rate effect on the concrete strength and softening rate is also expressed well by considering those effect in the constitutive laws.
