Delamination effects on fracture behavior of a pipeline steel: A numerical investigation of 3-D crack front fields and constraint

Autor(es)

Ruggieri, C. ^[1] ; Hippert, Jr., E. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Naval Architecture & Ocean Engn, BR-05508900 Sao Paulo - Brazil

^[2] Petrobras Dev & Res Ctr TMEC CENPES, Rio De Janeiro, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING; v. 128, p. 18-35, APR 2015.
• Citações Web of Science: 6

Resumo

This work addresses a numerical investigation of the crack front fields and effects of crack-tip constraint in conventional fracture specimens with prescribed transverse delamination cracks. One purpose of this study is to conduct a systematic evaluation of delamination effects in side-grooved and plane-sided C(T) and clamped SE(T) fracture specimens, which are commonly utilized in fracture toughness testing of pipeline steels. Another is to quantify the potential coupling influence of specimen geometry and delamination size on crack-tip constraint by means of the J-Q theory thereby providing valuable insight into the effect of delamination cracks on macroscopic fracture behavior in conventional fracture specimens. Laboratory testing of an API 5L X70 steel at room temperature provides the mechanical properties used in the numerical analysis incorporating delamination cracks with varying sizes. Nonlinear finite element analyses of very detailed 3-D finite element models of C(T) and clamped SE(T) fracture specimens for the API X70 pipeline steel enable assessing the effects of prescribed delamination cracks on the crack front fields and constraint with increased deformation levels as characterized by the J-integral. Overall, the present analyses reveal important features of 3-D crack front fields in fracture specimens with a crack-divider delamination that have a direct bearing on the often observed toughness increase in fracture testing of materials with through-thickness anisotropy in mechanical properties. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 12/13053-2 - Desenvolvimentos adicionais de um modelo micromecânico de fratura frágil e aplicações à metodologia da curva mestra
• Beneficiário: Claudio Ruggieri
• Modalidade de apoio: Auxílio à Pesquisa - Regular