Three-Dimensional Numerical Simulation On Meso-mechanics Damage Theory And CT Experiment Verification Of Failure Process In Concrete

In this paper, concrete is taken as three-phase composites consisting of aggregate, mortar and bond between aggregate and mortar. Based on meso-mechanics, the distortion, damage and failure of the concrete combined computation-on mechanics and damage-mechanics are researched. So the crack propagation, coalescence and failure of concrete is researched by damage by means of the software-ANSYS developed secondly. Main work of this paper include:1. A new math model and program of 3-D random aggregate model of concrete is established. This make it easy for aggregate sphere to quickly find out it is space location, so the speed of program's searching out the location of sphere centre is accelerated. In the same time the new program combine many programs into one, can create the aggregate sphere centre, distinguish the attributes of element material and distribute the different element attribute.2. Numerical simulations were carried out with meso-mechanics damage theory, which simulated the uniaxial compressive cylinder specimen. The decrease of elastic damage of concrete is described by the conduplicate-line damage evolvement model based on elastic damage constitutive relation; the degree of damage of concrete specimen is reflected by the degree of decreasing of elastic-modulus. Then, 3-D numerical model of the cylinder specimen is calculated. So the crack propagation, coalescence and failure of concrete is researched by damage,and the results of numerical simulation with CT experiment is compared and analyzed.3. The fracture probability model of meso-mechanic damage of concrete is established. The one or a set of likely fracture structure is confirmed in the established finite element mesh model of concrete. Probability fracture of meso-strucure is calculated under considering the effect degree of damage of every step .It is indicated that the selected meso-structure failure if the probability fractures equal 1.0.Under the action of outer load, crack propagation process of concrete is simulated and analyzed. So the damage andfracture process zone of concrete is researched.Through the numerical simulation on the failure process of concrete in this paper, the crack propagation, coalescence and failure essential of concrete material is explored instructively.