Fracture of a borosilicate glass under triaxial tension

Doquet, Véronique; Ali, Nazakat; Constantinescu, Andréï; Boutillon, Xavier

doi:10.1016/j.mechmat.2012.10.008

Cited by 16 publications

(13 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It also contains more or less spherical pores, as mentioned above. More details on the microstructure and thermo-mechanical properties of this glass whose T g is 502°C can be found in Dubé et al (2010), Doquet et al (2013) and Barth et al (2012).…”

Section: Methodsmentioning

confidence: 99%

“…Upon cooling, cracks may develop due to thermal gradients. This problem has been investigated in previous studies (Dubé et al, 2010;Doquet et al, 2013). However, since the radionuclides constitute an internal heat source and since several canisters are initially stored in the same room, the temperature inside the glass blocks remains high during a long period (above 400°C during the first day and above 350°C during three years, according to Barth et al, 2012), so that thermally-induced healing of the cracks can be expected, at least partially.…”

Section: Context Of the Studymentioning

confidence: 99%

“…Since the environment of the cracks that are likely to heal in nuclear waste blocks is not clear, both air and vacuum annealing were investigated in the present study. On the one hand, internal cracks -except those connected to the surface through the crack network -do not interact with ambient air, so that vacuum annealing might be considered representative of their condition, on the other hand, the cracks tend to initiate from pores -formed due to argon bubbling for homogenisation of the molten mixture -as shown in Doquet et al (2013). The moisture content of the gas trapped in those pores is not known, so that annealing in moist air should also be investigated.…”

Section: Open Questions and Present Studymentioning

confidence: 99%

See 2 more Smart Citations

Experimental and numerical study of crack healing in a nuclear glass

Doquet

Ali

Chabert

et al. 2015

Mechanics of Materials

Self Cite

View full text Add to dashboard Cite

International audiencea b s t r a c t An experimental study of thermally or water-induced crack healing in an inactive borosil-icate glass, chemically analogous to that used in France for the vitrification of nuclear waste was carried out. Partial welding of glass plates was observed after annealing in air at 425 °C (77 °C below T g) when at least 20 MPa compressive stress was applied, while annealing at 450 °C under 20 MPa led to a complete disappearance of the interface. Closure of indenta-tion-induced cracks was observed during annealing at 400 °C in an ESEM as a result of viscous relaxation of residual stresses but it did not constitute a sufficient proof of crack healing. DCDC specimens were thus pre-cracked in an ESEM and then either annealed at various temperatures (350–490 °C) in secondary vacuum or in air, or left in water at 70–90 °C, sometimes under a compressive stress normal to the crack face. The specimens were then reloaded in the ESEM and the crack opening displacements under a given load were compared to those measured during pre-cracking. The cracks were bridged by an alteration layer over a distance from the crack tip which decreased as loading increased. The restraining effect of these bridges on crack opening was assessed via finite element simulations, using interface elements. The tensile strength of the bridging layer was estimated as 27–39 MPa after vacuum annealing at 400 °C, 11–20 MPa after 15 days in water at 90 °C and 44–78 MPa after 11 days in water at 70 °C under 5 MPa normal compression. Partially healed cracks did not resume propagation from their former crack tip, but due to branch cracks re-initiated a few hundred microns behind it which grow avoiding the healed area. This behaviour was explained using finite element simulations

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Context Of the Studymentioning

confidence: 99%

Section: Open Questions and Present Studymentioning

confidence: 99%

See 1 more Smart Citation

Experimental and numerical study of crack healing in a nuclear glass

Doquet

Ali

Chabert

et al. 2015

Mechanics of Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…Unfortunately this method is not suitable for investigation of material properties under this state stress, for example for determining the so-called rupture characteristic". This method was used by modern scholars [3]. Obviously are the difficulties to define specific values of the limit of the all-round tensile strength.…”

Section: Abstract Abstractmentioning

confidence: 99%

“…The tests were carried out using the device [3] (Fig. 1) For comparison, the same series (7 pices) of samples were tested with the use of the same device under the conditions uniaxial tension (UAT).…”

Section: IImentioning

confidence: 99%

Uniform Tension: the Problem and the Solution

Ерёмичев¹

2017

HoBMSTU.SME

View full text Add to dashboard Cite

KeywordsWhen we need to plot the failure surface of a material, the "starting point" is of great importance. It is determined by results of uniform compression and uniform tension tests. The former is rather trivial, although greater technical difficulties arise when creating a pressure high enough to make the material fail. Implementing a uniform tension stress state, however, and especially simultaneously measuring the failure stress is a complex scientific and engineering task. We supply a brief review of articles on the subject. We describe the sample and the device for implementing triaxial tension we developed. We provide test results for plexiglas (PMMA) and carbon-carbon composite material samples To determine the surface of strength [1], of great importance is the "starting point" which is determined by the results of tests on a uniform all-round compression and a all-round uniform tension. The first definition is rather trivial, although associated with greater technical difficulties when creating the higher pressure at which the material collapses under compression. The creation of the stress state "all-round uniform tension" and especially the measurement of breaking stress at the same time, is a complex engineering task.One of the greatest scientists and educators in the field of strength of materials Feodos'ev V.I. in the book [2] wrote:"The only one method of the all-round homogeneous tension known at present time is the following: "The previously cooled solid homogeneous ball is quickly heated. The stress state indicated above will occur in the ball center. Unfortunately this method is not suitable for investigation of material properties under this state stress, for example for determining the so-called rupture characteristic". This method was used by modern scholars [3]. Obviously are the difficulties to define specific values of the limit of the all-round tensile strength. Strength at all-round uniform tension in [3] is determined indirectly by finite element method (FEM).Lately many works have been written which address the issues associated with the testing of materials under three axial tension. A review of these works is beyond the scope of this article. However, a large number of such works testify the importance of studying the properties of materials with uniform three-axis tensile.

show abstract

Brittle creep and subcritical crack propagation in glass submitted to triaxial conditions

et al. 2015

View full text Add to dashboard Cite

An experimental work is presented that aimed at improving our understanding of the mechanical evolution of cracks under brittle creep conditions. Brittle creep may be an important slow deformation process in the Earth's crust. Synthetic glass samples have been used to observe and document brittle creep due to slow crack‐propagation. A crack density of 0.05 was introduced in intact synthetic glass samples by thermal shock. Creep tests were performed at constant confining pressure (15 MPa) for water saturated conditions. Data were obtained by maintaining the differential‐stress constant in steps of 24 h duration. A set of sensors allowed us to record strains and acoustic emissions during creep. The effect of temperature on creep was investigated from ambient temperature to 70°C. The activation energy for crack growth was found to be 32 kJ/mol. In secondary creep, a large dilatancy was observed that did not occur in constant strain rate tests. This is correlated to acoustic emission activity associated with crack growth. As a consequence, slow crack growth has been evidenced in glass. Beyond secondary creep, failure in tertiary creep was found to be a progressive process. The data are interpreted through a previously developed micromechanical damage model that describes crack propagation. This model allows one to predict the secondary brittle creep phase and also to give an analytical expression for the time to rupture. Comparison between glass and crystalline rock indicates that the brittle creep behavior is probably controlled by the same process even if stress sensitivity for glass is lower than for rocks.

show abstract

Fracture of a borosilicate glass under triaxial tension

Cited by 16 publications

References 16 publications

Experimental and numerical study of crack healing in a nuclear glass

Experimental and numerical study of crack healing in a nuclear glass

Uniform Tension: the Problem and the Solution

Brittle creep and subcritical crack propagation in glass submitted to triaxial conditions

Contact Info

Product

Resources

About