Fracture Mechanics Description of Crack Propagation in Ceramic Laminates

abstrakt

angličtina

The layered ceramic composites are in the interest of the researches, because of their improved fracture toughness, strength and reliability in comparison to monolithic ceramics. Multilayered design combines layers with differentmaterial properties and especially coefficients of thermal expansion. Due to this fact, during the sintering process, the high residual stresses appear in the laminate, which subsequently significantly influence the fracture behavior. The contribution is focused on the alumina-zirconia layered system with strong compressive residual stresses serving as a barrier for the crack propagation through the laminate body. Propagating crack can stay arrested in the compressive layer or is strongly deflected from the original direction of crack propagation. It leads to the higher value of so-called apparent fracture toughness of the ceramic laminate. The assumptions of the linear elastic fracture mechanics and small scale yielding condition are considered in the contribution for the description of the crack propagation. The stress field is obtained numerically by using the finite element method.Thetheory based on strain energy density factor was used for determination of the crack behavior. The work contributes to the better understanding of failure process of ceramic laminates.

Ceramic laminate, residual stresses, crack propagation direction, strain energy density factor.

ŠTEGNEROVÁ, K.; NÁHLÍK, L.; HUTAŘ, P.

13. 4. 2015

Česká technika – Nakladatelství ČVUT

Thákurova 1, Praha 6

978-80-01-05708-7

APPLIED MECHANICS 2015 – Book of Abstracts

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