Full-field characterisation of the deformation near fatigue crack tips using advanced imaging and diffraction techniques

Authors: T. Wigger (University of Portsmouth)
Co-authored by industrial partner: No

Type: Thesis

State: Published (Approved)
Published: March 2019
Diamond Proposal Number(s): 13579 , 12585

Open Access Open Access

Abstract: Critical engineering components and structures are often exposed to cyclic loads and hence susceptible to fatigue fracture. The integrity of many components and structures is assessed following a damage tolerant approach, allowing fatigue cracks to grow to a sub-critical size before repairing or replacing a part. Commonly, damage tolerant approaches are based on linear elastic fracture mechanics without considering the plastic deformation known to occur at the crack front, which may have an influence on steady-state crack propagation. On the other hand, shielding effects in the crack wake, such as closure, are often included in crack growth models, although their impacts on fatigue crack growth behaviour have by large not been directly investigated. Full-field studies of a fatigue crack tip have, until very recently, been restricted to limited model materials and mostly to surfaces, whilst the 3D bulk behaviour around a fatigue crack tip has rarely been examined. This work aims to address these issues by revisiting fatigue crack growth using imaging and diffraction techniques on selected engineering materials.

Journal Keywords: Fatigue; Fracture; Crack tip fields; Image correlation; X-ray diffraction; Error assessment

Subject Areas: Engineering, Materials

Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Added On: 19/12/2019 14:26


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