Propagation and Deflection of Electric-Field-Induced Microcracks in 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 Ferroelectric Single Crystals

2007 ◽  
Vol 336-338 ◽  
pp. 363-366
Author(s):  
Yong Zhang ◽  
Z. Xu
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Maximum Energy ◽  
Transmission Electron Microcopy ◽  
Transmission Electron ◽  
Subsequent Propagation ◽  
Energy Release Rate Criterion ◽  
Rate Criterion ◽  
Maximum Energy Release

Propagation and deflection of microcracks driven by electric loading in <001>-oriented 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 ferroelectric single crystals were investigated using an in-situ transmission electron microcopy (TEM) technique. The static observation of the domain pattern revealed the coexistence of sub-micrometer and nano-meter domains. Electric field induced deviation from the main microcrack path and subsequent propagation along the direction almost perpendicular to the electric field were observed directly. A qualitative analyses is given based on the maximum energy release rate criterion.

Fracture Under Combined Loads by Maximum-Energy-Release-Rate Criterion

1978 ◽  
Vol 45 (3) ◽  
pp. 553-558 ◽  
Author(s):  
C.-H. Wu
Keyword(s):  
Maximum Stress ◽  
Maximum Energy ◽  
Antiplane Shear ◽  
Combined Loads ◽  
Biaxial Load ◽  
Title Problem ◽  
Minimum Strain Energy ◽  
Energy Release Rate Criterion ◽  
Rate Criterion ◽  
Maximum Energy Release

The title problem is studied for the cases: (1) crack-perpendicular tension and crack-parallel shear, (2) plane biaxial load, (3) crack-parallel shear and antiplane shear, and (4) unidirectional load and antiplane shear. All the results are based on a fundamental investigation reported in references [1, 2], the results of which are partly exact, and partly asymptotic and numerical. Neither the maximum-stress nor the minimum-strain-energy-density criterion indicates a coupling between plane and antiplane loads.

Crack Propagation at and Near Bimaterial Interfaces: Linear Analysis

1994 ◽  
Vol 61 (3) ◽  
pp. 560-566 ◽  
Author(s):  
P. H. Geubelle ◽  
W. G. Knauss
Keyword(s):  
Crack Extension ◽  
Small Strain ◽  
Linear Analysis ◽  
Maximum Energy ◽  
Propagation Direction ◽  
Elastic Solids ◽  
Bimaterial Interfaces ◽  
Energy Release Rate Criterion ◽  
Rate Criterion ◽  
Maximum Energy Release

The problem of the growth of a crack located at the interface between two linearly elastic solids is considered when conditions promoting propagation along and/or away from the interface prevail. Both a stress and a maximum energy release rate criterion are examined. It is found that in contrast to the corresponding problem for crack growth in homogeneous solids, no unique propagation direction results when continuum considerations prevail alone. Uniqueness is established only upon invoking a presumably material dictated minimum crack extension size. The result for this linearized analysis are compared with experimental observations on kink fracture involving two elastomers of small strain capabilities.

Equivalence for Two Interacting Parallel Cracks

1998 ◽  
Vol 120 (4) ◽  
pp. 424-430 ◽  
Author(s):  
J. H. Kuang ◽  
C. K. Chen
Keyword(s):  
Safety Margin ◽  
Maximum Energy ◽  
Pressure Vessels ◽  
Multiple Cracks ◽  
Intensity Factors ◽  
Single Crack ◽  
Parallel Cracks ◽  
Energy Release Rate Criterion ◽  
Rate Criterion ◽  
Maximum Energy Release

Crack failure prediction is a prerequisite to assess the safety margin for pressure vessels with interacting parallel cracks. Therefore, an alternating iteration method with approximated image traction is employed in this study to assess the stress intensity factors of two stacked parallel cracks. The predicted crack intensity factors for these parallel cracks correlate well with the recent available solutions in literature. Maximum-energy-release-rate criterion is also utilized for converting problems of multiple cracks into a single crack in mode I. Results demonstrate that a shorter secondary parallel crack may enhance the equivalent crack primarily in the regions 0 < h/2a1 ≤ 0.8 and −1 ≤ t/a1 ≤ 1. The predicted results can be used to evaluate the conformability of simple proximity rules suggested by ASME Boiler & Pressure Vessel Code (ASME B&PV Code).

Sign in / Sign up

Export Citation Format

Share Document