Local stress intensity factors for surface cracks in plates under power-shaped stress distributions

East Antarctic ice discharged by Byrd Glacier continues as a flowband to the calving front of the Ross Ice Shelf. Flow across the grounding line changes from compressive to extensive as it leaves the fjord through the Transantarctic Mountains occupied by Byrd Glacier. Magnitudes of the longitudinal compressive stress that suppress opening of transverse tensile cracks are calculated for the flowband. As compressive back stresses diminish, initial depths and subsequent growth of these cracks, and their spacing, are calculated using theories of elastic and ductile fracture mechanics. Cracks are initially about one millimeter wide, with approximately 30 m depths and 20 m spacings for a back stress of 83 kPa at a distance of 50 km beyond the fjord, where floating ice is 600 m thick. When these crevasses penetrate the whole ice thickness, they release tabular icebergs 20 km to 100 km wide, spaced parallel to the calving front of the Ross Ice Shelf.

show abstract

“…With the stress written in this form, the SIF for mode I cracks, those cracks that open in tension, is K I and is given by (Fett et al 1990):…”

Section: Fracture Mechanicsmentioning

confidence: 99%

“…This expression is determined by Fett et al (1990) to be valid for N ≤ 5 and normalized crevasse depths α = a/H ≤ 0.9. The A i are polynomials in α given by (correction in A 3 by Rist et al 2002…”

Section: Fracture Mechanicsmentioning

confidence: 99%

Fracture and back stress along the Byrd Glacier flowband on the Ross Ice Shelf

Kenneally

Hughes

2004

Antartic science

View full text Add to dashboard Cite

show abstract

“…For simplicity, the critical flaw size is evaluated based on the Griffith equation (

a = K_{Ic}^2/(\Pi{( {0.73{\sigma _{max}}} )^2}

) using the crack tip toughness as the critical stress intensity factor,

\ {K_{Ic}}

24 . This is justified as, even for soft PZT, the determined crack closure stresses are below 20 MPa, 25 and the R‐curves in PZT 11 and lead‐free 3 piezoceramics plateau only at a considerable crack extension of several hundred micrometers, irrelevant for enhancing the fracture strength.…”

Section: Resultsmentioning

confidence: 99%

Deformation and bending strength of high‐performance lead‐free piezoceramics

Venkataraman

Isaia

Gong³

et al. 2022

J Am Ceram Soc

View full text Add to dashboard Cite

Bending strength of commercially relevant lead-free piezoceramics -0.935Na 0.5 Bi 0.5 TiO 3 -0.065BaTiO 3 (NBT-6.5BT) with and without acceptor Zn-doping and 0.92(K 0.5 Na 0.5 )NbO 3 -0.02(Bi 0.5 Li 0.5 )TiO 3 -xBaZrO3; x = 0.06, 0.07 (KNN-BZ100x) have been quantified using 4-point bending tests and contrasted to that of commercial lead zirconate titanate (PZT, PIC151). The compressive and tensile strength probed using additional strain gauges under 4-point bending indicate negligible non-linear deformation, in stark contrast to that of commercial PIC151. The bending strength of KNN-BZ100x is about 100 MPa, comparable to PIC151, while that of NBT-6.5BT-based materials is about twice that of PIC151 at ∼160 MPa. These results are rationalized based on the intrinsic characteristics of the lead-free piezoceramics in terms of fracture toughness, coercive stress, and Young's modulus. Weibull statistics indicate a higher fracture probability for KNN-based materials, with NBT-6.5BT-based materials featuring Weibull modulus twice that of KNN-based materials.

show abstract

“…The SIF for the axial inner surface crack of infinite length has been computed from [18][19][20][21][22][23] …”

Section: Analysis Of Straight Segments Of the Pipeline During Steady mentioning

confidence: 99%

“…For an inner axial semi-elliptical crack, the following formula was adopted [18][19][20][21][22] to compute SIF…”

Section: Analysis Of Straight Segments Of the Pipeline During Steady mentioning

confidence: 99%

Failure assessment analysis of pipelines for heat and power generating plants according to the SINTAP procedures

Dzioba

2005

International Journal of Pressure Vessels and Piping

View full text Add to dashboard Cite

Local stress intensity factors for surface cracks in plates under power-shaped stress distributions

Cited by 29 publications

References 5 publications

Fracture and back stress along the Byrd Glacier flowband on the Ross Ice Shelf

Fracture and back stress along the Byrd Glacier flowband on the Ross Ice Shelf

Deformation and bending strength of high‐performance lead‐free piezoceramics

Failure assessment analysis of pipelines for heat and power generating plants according to the SINTAP procedures

Contact Info

Product

Resources

About