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Fracture mechanics by three-dimensional crack-tip synchrotron X-ray microscopy.

Withers PJ - Philos Trans A Math Phys Eng Sci (2015)

Bottom Line: To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping.X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces.It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement.

View Article: PubMed Central - PubMed

Affiliation: Manchester X-ray Imaging Facility, School of Materials, Manchester University, Manchester M13 9PL, UK Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, UK p.j.withers@manchester.ac.uk.

ABSTRACT
To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capable of both imaging and diffraction are beginning to emerge, such as ID15 at the European Synchrotron Radiation Facility and JEEP at the Diamond Light Source. This review explores the concept of three-dimensional crack-tip X-ray microscopy, bringing them together to probe the crack-tip behaviour under realistic environmental and loading conditions and to extract quantitative fracture mechanics information about the local crack-tip environment. X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces. Time-lapse CT, besides providing information about the three-dimensional nature of the crack and its local growth rate, can also provide information as to the activation of extrinsic toughening mechanisms such as crack deflection, crack-tip zone shielding, crack bridging and crack closure. It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement. Finally, further opportunities for synchrotron X-ray microscopy are explored.

No MeSH data available.


Related in: MedlinePlus

Time-lapse synchrotron X-ray tomographic cross-sections (I13 Diamond Light Source) showing crack deflection in a freeze cast layered ceramic (approx. 4×0.8×1.6 mm) fractured in bending. (Courtesy of D Eastwood, E. D'Elia, E. Saiz. S Yue, C. Rau, P.J. Withers and P. D. Lee.)
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RSTA20130157F13: Time-lapse synchrotron X-ray tomographic cross-sections (I13 Diamond Light Source) showing crack deflection in a freeze cast layered ceramic (approx. 4×0.8×1.6 mm) fractured in bending. (Courtesy of D Eastwood, E. D'Elia, E. Saiz. S Yue, C. Rau, P.J. Withers and P. D. Lee.)

Mentions: Recently, there has been a great deal of interest in mimicking the layered structured of many natural systems, originally on the submillimetre scale by stacking thin ceramic sheets [81] and more recently at the tens of micrometres scale by freeze casting (ice templating) [3,82]. Time-lapse CT is especially well suited to the characterization of the crack deflection events and can provide key information about the sequence of crack growth, bifurcation and deflection as well as the opening of the dominant crack, as shown in figure 13.Figure 13.


Fracture mechanics by three-dimensional crack-tip synchrotron X-ray microscopy.

Withers PJ - Philos Trans A Math Phys Eng Sci (2015)

Time-lapse synchrotron X-ray tomographic cross-sections (I13 Diamond Light Source) showing crack deflection in a freeze cast layered ceramic (approx. 4×0.8×1.6 mm) fractured in bending. (Courtesy of D Eastwood, E. D'Elia, E. Saiz. S Yue, C. Rau, P.J. Withers and P. D. Lee.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4308984&req=5

RSTA20130157F13: Time-lapse synchrotron X-ray tomographic cross-sections (I13 Diamond Light Source) showing crack deflection in a freeze cast layered ceramic (approx. 4×0.8×1.6 mm) fractured in bending. (Courtesy of D Eastwood, E. D'Elia, E. Saiz. S Yue, C. Rau, P.J. Withers and P. D. Lee.)
Mentions: Recently, there has been a great deal of interest in mimicking the layered structured of many natural systems, originally on the submillimetre scale by stacking thin ceramic sheets [81] and more recently at the tens of micrometres scale by freeze casting (ice templating) [3,82]. Time-lapse CT is especially well suited to the characterization of the crack deflection events and can provide key information about the sequence of crack growth, bifurcation and deflection as well as the opening of the dominant crack, as shown in figure 13.Figure 13.

Bottom Line: To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping.X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces.It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement.

View Article: PubMed Central - PubMed

Affiliation: Manchester X-ray Imaging Facility, School of Materials, Manchester University, Manchester M13 9PL, UK Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, UK p.j.withers@manchester.ac.uk.

ABSTRACT
To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capable of both imaging and diffraction are beginning to emerge, such as ID15 at the European Synchrotron Radiation Facility and JEEP at the Diamond Light Source. This review explores the concept of three-dimensional crack-tip X-ray microscopy, bringing them together to probe the crack-tip behaviour under realistic environmental and loading conditions and to extract quantitative fracture mechanics information about the local crack-tip environment. X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces. Time-lapse CT, besides providing information about the three-dimensional nature of the crack and its local growth rate, can also provide information as to the activation of extrinsic toughening mechanisms such as crack deflection, crack-tip zone shielding, crack bridging and crack closure. It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement. Finally, further opportunities for synchrotron X-ray microscopy are explored.

No MeSH data available.


Related in: MedlinePlus