Impact of the non-linear character of the compressive stress–strain curves on thermal and mechanical properties of porous microcracked ceramics

Bruno, Giovanni; Kilali, Yassine; Efremov, Alexander

doi:10.1016/j.jeurceramsoc.2012.09.004

Cited by 14 publications

(10 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It implies the density of microcracks generated by cooling of about ρ = 0.43. Interestingly, this value agrees with estimates provided by stress–strain curves in the work of Bruno et al, as described in Section .…”

Section: Microstresses Due To Cooling Of Polycrystalline Ceramics: Desupporting

confidence: 90%

“…Experimental and theoretical fracture mechanics can also be used to the above‐stated aim. However, usual fracture mechanics tests can only be applied to estimate an equivalent fracture toughness (i.e., accounting for presence of microcracks): As microcracks induce a highly nonlinear stress–strain behavior of the material (Bruno et al), linear fracture mechanics cannot be used to determine fracture toughness, and therefore to calculate intergranular strength.…”

Section: Microstresses Due To Cooling Of Polycrystalline Ceramics: Dementioning

confidence: 99%

See 1 more Smart Citation

Microstructure–Property Connections for Porous Ceramics: The Possibilities Offered by Micromechanics

Bruno

Kachanov

2016

J. Am. Ceram. Soc.

Self Cite

View full text Add to dashboard Cite

Microstructure of porous ceramics is highly “irregular”: it comprises pores and microcracks of diverse shapes and orientations. This makes their quantitative modeling challenging, and one often resorts to empirical relations containing fitting parameters and having somewhat uncertain range of applicability. We review the substantial progress made in modeling of “irregular” microstructures that does not seem to have been sufficiently utilized in the context of ceramics. We discuss the possibilities offered by micromechanics in developing microstructure–property relations for porous microcracked ceramics. After an overview of relevant micromechanics topics, we focus on several issues of specific interest for ceramics: nonlinear stress–strain behavior, effective elastic properties, and thermally induced microcracking. We discuss extraction of microscale parameters (such as strength of the intergranular cohesion, density of cracks and pores, etc.) from macroscopic data and identify the extent of uncertainty in this process. We also argue that there is no quantitative correlation between fracturing process and the loss of elastic stiffness.

show abstract

Section: Microstresses Due To Cooling Of Polycrystalline Ceramics: Desupporting

confidence: 90%

Section: Microstresses Due To Cooling Of Polycrystalline Ceramics: Dementioning

confidence: 99%

Microstructure–Property Connections for Porous Ceramics: The Possibilities Offered by Micromechanics

Bruno

Kachanov

2016

J. Am. Ceram. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Table 2 summarizes the microstructural parameters m and ρ as a function of porosity for bare and coated filter materials for which high temperature Young's modulus measurements were performed. The microcrack density values for porous cordierite materials found here are in the range of 0.3-0.5 and agree well with values found in prior work [49] using uniaxial (compression) testing.…”

Section: Estimation Of Microstructural Parameterssupporting

confidence: 88%

The effect of porosity and microcracking on the thermomechanical properties of cordierite

Shyam

Bruno

Watkins

et al. 2015

Journal of the European Ceramic Society

View full text Add to dashboard Cite

The effect of porosity and microcracking on the mechanical properties (strength, fracture toughness, Young's modulus, and fracture energy) and thermal expansion of diesel particulate filter (DPF) grade cordierite materials has been investigated. A method to deconvolute the effect of porosity and microcracking on Young's modulus is proposed. In addition, the microcrack density and the pore morphology factor are calculated by applying a micromechanical differential scheme. The values of the investigated mechanical properties are shown to decrease with an increase in porosity, but the thermal expansion values are insensitive to porosity. The variation in mechanical properties as a function of porosity leads to distinct porosity dependence of thermal shock resistance for crack initiation and crack propagation for DPF grade synthetic cordierite.

show abstract

“…Porosity and microcracks are the two major types of defects inherent in porous microcracked ceramics where cracks are defined as a displacement discontinuity across which tensile traction is zero or decreasing with opening . As reported by Bruno et al ., the microcracks in these materials can be categorized as thermally induced microcracks (or the initial microcrack distribution that forms due to thermal stresses associated with processing) and mechanically induced microcracks (new microcrack distribution that forms due to mechanical stresses). In other words, the overall mechanical response of these materials is not only related to the combination of preexisting defects but also the nucleation, growth, and coalescence of new defects .…”

Section: Discussionmentioning

confidence: 97%

“…However, values of Young's modulus obtained from such studies are dependent on the assumptions used in the formulation of the FE/analytical models. Other researchers have applied macrosize specimens of various size and shapes (rectangular prism, cylindrical, O ring, ring‐on‐ring) to obtain the elastic properties of porous ceramic materials. It is, however, important to recognize (as mentioned in ASTM C1674‐11) that mechanical properties obtained from such a response are not only a function of microstructure (grains/domain) and defects (porosity and microcrack) but also the structural architecture (i.e., channel porosity) that resides in a test specimen.…”

Section: Introductionmentioning

confidence: 99%

The Uniaxial Tensile Response of Porous and Microcracked Ceramic Materials

et al. 2013

View full text Add to dashboard Cite

The uniaxial tensile stress-strain behavior of three porous ceramic materials was determined at ambient conditions. Test specimens in the form of thin beams were obtained from the walls of diesel particulate filter honeycombs and tested using a microtesting system. A digital image correlation technique was used to obtain full-field 2D in-plane surface displacement maps during tensile loading, and in turn, the 2D strains obtained from displacement fields were used to determine the Secant modulus, Young's modulus, and initial Poisson's ratio of the three porous ceramic materials. Successive unloading-reloading experiments were performed at different levels of stress to decouple the linear elastic, anelastic, and inelastic response in these materials. It was found that the stress-strain response of these materials was nonlinear and that the degree of nonlinearity is related to the initial microcrack density and evolution of damage in the material.

show abstract

Impact of the non-linear character of the compressive stress–strain curves on thermal and mechanical properties of porous microcracked ceramics

Cited by 14 publications

References 33 publications

Microstructure–Property Connections for Porous Ceramics: The Possibilities Offered by Micromechanics

Microstructure–Property Connections for Porous Ceramics: The Possibilities Offered by Micromechanics

The effect of porosity and microcracking on the thermomechanical properties of cordierite

The Uniaxial Tensile Response of Porous and Microcracked Ceramic Materials

Contact Info

Product

Resources

About