Rakenteiden Mekaniikka | 2019
On continuum damage mechanics
Abstract
A material containing spherical microvoids with a Hookean matrix response was shown to take the appearance usually applied in continuum damage mechanics. However, the commonly used variable damage D was replaced with the void volume fraction f , which has a clear physical meaning, and the elastic strain tensor \\Bold {e}^e with the damage-elastic strain tensor \\Bold {e}^{de}. The postulate of strain equivalence with the effective stress concept was reformulated and applied to a case where the response of the matrix obeys Hooke’s law. In contrast to many other studies, in the derived relation between the effective stress tensor \\Bold {\\Tilde{σ}} and the stress tensor \\Bold {σ}, the tensor \\Bold {\\Tilde{σ}} is symmetric. A uniaxial bar model was introduce for clarifying the derived results. Other candidates for damage were demonstrated by studying the effect of carbide coarsening on creep rate.