In-situ Estimation of Surface Crack Shape from Crack Opening Displacement by Use of NCOD Database System

摘要

This paper proposes an in-situ estimation of crack shape from crack opening displacement (COD) by using of a visualized database system consisting of numerical calculation data of normalized crack opening displacement (NCOD) for some kinds of crack types. First the relation between crack depth and corresponding NCOD is discussed in detail based on FE analysis results, from which a crack shape estimation principle is deduced. Then visualized software named NCOD database system is developed to facilitate quick and convenient in-situ estimation of crack shape. Shapes of three kinds of surface crack, partial circle crack in plate, fatigue cracks in gusset weld joint and in large-scale member, are successfully estimated by using this system.