ON A NON-LINEAR FINITE ELEMENT ANALYSIS PROCEDURE BASED ON HIERARCHICAL DIGITAL IMAGE FOR CONCRETE MATERIALS WITH CONSIDERATION OF COARSE-AGGREGATE-AND-MORTAR INTERFACE

摘要

This paper presents a non-linear finite element analysis procedure based on a digital image for concrete materials. Our final goal is to simulate the three-dimensional compressive non-linear behaviors of concrete materials with consideration of their local tensile failures. Concrete materials are modeled as two-phase composites consisting of coarse aggregates and mortar. Digital image processing is directly used to generate a finite a finite element mesh. A new mixed finite element in which a high-resolutional digital image is embedded is developed to model smooth interfaces between coarse aggregates and mortar on the finite element mesh of low-resolutional digital image. This element is able not only to represent the strain jump caused by the existence of different materials but also to capture the displacement jump caused by interfacial cracks. A two-dimensional numerical example is shown.