Coalescence-controlled anisotropic ductile fracture

The anisotropic ductile fracture of rolled plates containing elongated incl usions is promoted by both the dilational growth of voids and the coalescen ce process. In the present article, the emphasis is laid on the latter proc ess. The effects of void shape and mainly of inter-particle spacings are in vestigated. Two types of coalescence models ale compared: a localization-ba sed model and plastic limit-lend models. The capabilities of both approache s to incorporate shape change and spacing effects are discussed. These mode ls are used to predict the fracture properties of two low alloy steels cont aining mainly manganese sulfide inclusions. Both materials are characterize d in different loading directions. Microstructure data inferred from quanti tative metallography are used to derive theoretical values of critical void volume fractions at incipient coalescence. These values are used in FE-cal culations of axisymmetrically notched specimens with different notch radii and lending directions.