Nonlocal Fracture Analysis - Microcrack Interaction Approach

This paper on "Nonlocal Fracture Analysis - Microcrack Interaction Approach" was presented at the NAFEMS World Congress on Design, Simulation & Optimisation: Reliability & Applicability of Computational Methods - 9-11 April 1997, Stuttgart, Germany.

Summary

As a consequence of damage and localization phenomena the traditional local macroscopical smeared fracture finite element analysis of quasibrittle materials, such as concrete, is meaningless. Consequently, the nonlocal analysis has to be used. In the present paper a brief review of the new nonlocal approach which is based on the interaction of microcracks is presented. The method consists of the long-range interaction and so called local averaging. The first controls the crack propagation and the second is responsible for the correct modelling of the material energy consumption capacity during the crack growth. It is discussed how the nonlocal material model parameters may be identified from the standard material fracture parameters such as tensile strength, concrete fracture energy and maximum aggregate size. The nonlocal microcrack interaction approach is compared with the nonlocal strain approach and possible simplifications are considered. The application of the method is illustrated on one numerical example.