Effect of Weld Strength Mismatch on Elastic-Plastic Fracture Parameters

This study quantifies the effect of weld strength mismatch on applied J, applied CTOD, and crack-tip constraint for both remote tensile and bending loads. Very detailed elastic-plastic finite element models for a wide range of geometrical configurations and material properties provide the fundamental quantities needed to derive fracture mechanics parameters. Equations in existing fracture test standards which relate J (and CTOD) to measurable quantities (i.e. load, plastic work, plastic displacement) are investigated for single edge notch bend, SE(B), specimens to ascertain if modifications are required for mismatched weldments. This study also addresses mismatch effects on equations which relate J (and CTOD) for small cracks in tension to nominal applied loads. Equations of this type are used to assess the integrity of structures against fracture. The interaction of weld strength mismatch and of finite specimen size effects on fracture toughness is quantified using the micromechanics approach developed by Dodds and Anderson for cleavage fracture. These investigations extend significantly the current understanding of strength mismatch effects on weldment fracture. Moreover, procedures are developed which enable accurate estimation of fracture driving force in both SE(B) specimens and tension loaded structures.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Civil Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Kirk, Mark Todd

Contributors dc:contributor

• Dodds, R.,

• Engineering, Civil
• Engineering, Mechanical

Identifier

(UMI)AAI9305583

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72192