An approximate method for residual stress calculation in functionally graded materials

Becker, T.L.; Cannon, R.M.; Ritchie, Robert O.

doi:10.1016/s0167-6636(99)00042-3

Cited by 47 publications

(22 citation statements)

References 16 publications

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“…The discs exibiting a sigmoidal transition between framework and venner presented a great thermal stress reduction relative to bilayered discs, but they were slightly higher than those seen in discs featuring a power law function. Sigmoidal gradient shapes are typical profiles resulting from the interdiffusion of two materials [41]. A continuous change in composition was adopted in this study, however this structure is fairly complex to manufacture, thus stepwise transition using several layers has been often adopted in the production of graded materials.…”

Section: Discussionmentioning

confidence: 99%

Thermal residual stresses in bilayered, trilayered and graded dental ceramics

Fabris

Souza

Silva

et al. 2017

Ceramics International

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Layered ceramic systems are usually hit by residual thermal stresses created during cooling from high processing temperature. The purpose of this study was to determine the thermal residual stresses at different ceramic multi-layered systems and evaluate their influence on the bending stress distribution. Finite elements method was used to evaluate the residual stresses in zirconia-porcelain and alumina-porcelain multi-layered discs and to simulate the ‘piston-on-ring’ test. Temperature-dependent material properties were used. Three different multi-layered designs were simulated: a conventional bilayered design; a trilayered design, with an intermediate composite layer with constant composition; and a graded design, with an intermediate layer with gradation of properties. Parameters such as the interlayer thickness and composition profiles were varied in the study. Alumina-porcelain discs present smaller residual stress than the zirconia-porcelain discs, regardless of the type of design. The homogeneous interlayer can yield a reduction of ~40% in thermal stress relative to bilayered systems. Thinner interlayers favoured the formation of lower thermal stresses. The graded discs showed the lowest thermal stresses for a gradation profile given by power law function with p=2. The bending stresses were significantly affected by the thermal stresses in the discs. The risk of failure for all-ceramic dental restorative systems can be significantly reduced by using trilayered systems (homogenous or graded interlayer) with the proper design.

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Section: Discussionmentioning

confidence: 99%

Thermal residual stresses in bilayered, trilayered and graded dental ceramics

Fabris

Souza

Silva

et al. 2017

Ceramics International

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“…For a strain-controlled situation, the stresses near the crack tip are approximated by multiplication of the conventional singular terms with E(x)/E(0), where E(0) denotes the Young's modulus at the crack tip (e.g., Becker et al 2000Becker et al , 2002. A corresponding procedure can be applied for a stress-controlled situation, see Sect.…”

Section: Materials Property Variations and Singular Fieldsmentioning

confidence: 99%

Semi-analytical approaches to assess the crack driving force in periodically heterogeneous elastic materials

et al. 2011

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When a crack propagates in a heterogeneous elastic material, its crack driving force depends strongly on the distribution of the local stiffness near the crack tip. In materials with periodic spatial variations of the Young's modulus, shielding and antishielding effects appear, i.e. the crack driving force is reduced or enhanced, compared to a homogeneous material. The effect is of great practical relevance, since it may lead to a strong increase of the fracture resistance. The concept of configurational forces (CCF) offers an established procedure for calculating the crack driving force. A very general relation for the periodic variation of Young's modulus is applied, allowing the description of both harmonically varying and layered microstructures. Numerical results are presented. Two semi-analytical approximation concepts, based on either the CCF or the moduli perturbation concept, are introduced and discussed. Comparisons are provided and recommendations given.

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“…Many FGM applications are intended to operate under severe thermomechanical conditions that involve considering both the temperature dependence of the constituents [1,2] and the residual stresses [3,4]. The micromechanical models usually used to estimate the effective thermomechanical moduli of FGMs, on the other hand, are based on linear thermoelasticity, where (i) the changes in temperature are assumed to be small, (ii) the material moduli are assumed to be independent of temperature, and (iii) the effects of initial eigenstrains associated with the residual stresses are neglected.…”

Section: Introductionmentioning

confidence: 99%

Effective thermoelastic moduli of FGMs with temperature-dependent constituents and initial eigenstrains

Boussaa

2013

J. Phys.: Conf. Ser.

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Abstract. We outline a procedure for incorporating the effects on the effective thermoelastic moduli of composites of (i) the temperature dependence of the constituents and (ii) the presence of initial eigenstrains. The procedure uses a unified thermodynamic treatment, which assumes small strains, finite changes in temperature, and initial eigenstrains. The procedure is illustrated by deriving the effective values of the isothermal compliance tensor, the thermal expansion tensor, and the heat capacity per unit reference volume at constant stress. The procedure is of particular interest in the modeling of thermoelastic FGMs operating under thermal conditions where the material properties are liable to depend on temperature.

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An approximate method for residual stress calculation in functionally graded materials

Cited by 47 publications

References 16 publications

Thermal residual stresses in bilayered, trilayered and graded dental ceramics

Thermal residual stresses in bilayered, trilayered and graded dental ceramics

Semi-analytical approaches to assess the crack driving force in periodically heterogeneous elastic materials

Effective thermoelastic moduli of FGMs with temperature-dependent constituents and initial eigenstrains

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