FINITE ELEMENT ANALYSIS OF CRACKED MULTI-LAYERED SYSTEM

Three super elements are developed for the analysis of stress intensity factors. The first element is for single material crack problems and the other two elements are for a crack either lying along or perpendicular to the interface of two homogeneous elastic materials. The William stress function is used in conjunction with the hybrid finite element to develop such elements.;The present super elements are distinguished by their efficiency, accuracy and easy formulation.;The concept of the locality effects of cracks on the stresses and displacements is used to extend the bi-material finite element approaches for the analysis of multi-layered crack problems.;As a direct application of multi-layered crack problems, the stress intensity factors are calculated for the following cracked multi-layered pavements. (1) Multi-layered pavement with a crack in the top layer; (2) The cracked beam over an elastic support; (3) Multi-layered pavement with over-lay containing a crack in the asphalt layer and having a crack length equal to the asphalt layer depth. (4) Multi-layered pavement with a splitting (separation) between the first two layers.;Four finite element programs are developed to compare the present finite element approach with other three finite element approaches available in the literature for single material crack problems. Also some numerical examples on bi-material crack problems are presented and solved by the present bi-material finite element approaches. Comparisons with the available theoretical solutions in the literature are given.