Experimental and Computational Study of Ductile Fracture in Small Punch Tests


GÜLÇİMEN ÇAKAN B. , Soyarslan C., Bargmann S., Hahner P.

MATERIALS, vol.10, no.10, 2017 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 10 Issue: 10
  • Publication Date: 2017
  • Doi Number: 10.3390/ma10101185
  • Title of Journal : MATERIALS
  • Keywords: small punch test, P91 steel, ductile fracture, gurson's plasticity model, nonlocal plasticity, SCALE YIELDING CONDITIONS, CRACK-GROWTH, NONLOCAL DAMAGE, VOID NUCLEATION, NEURAL-NETWORKS, P91 WELDMENT, SHEAR, DEFORMATION, TOUGHNESS, FAILURE

Abstract

A unified experimental-computational study on ductile fracture initiation and propagation during small punch testing is presented. Tests are carried out at room temperature with unnotched disks of different thicknesses where large-scale yielding prevails. In thinner specimens, the fracture occurs with severe necking under membrane tension, whereas for thicker ones a through thickness shearing mode prevails changing the crack orientation relative to the loading direction. Computational studies involve finite element simulations using a shear modified Gurson-Tvergaard-Needleman porous plasticity model with an integral-type nonlocal formulation. The predicted punch load-displacement curves and deformed profiles are in good agreement with the experimental results.