The paper deals with crack propagation through an interface between two elastic materials. The basic idea of developing stability criteria of general singular stress concentrators introduced in the first part is applied to the case of a crack with its tip at the interface between two different materials. Three different stability criteria based on different physical principles are presented and a numerical example with their mutual comparison is carried out. A procedure based on a generalized strain energy density factor is shown which makes it possible to estimate the further direction of crack propagation after the crack has passed the interface. The procedure presented is applied in the numerical examples. and Obsahuje seznam literatury
In this paper, stability of linear neutral systems with distributed delay is investigated. A bounded half circular region which includes all unstable characteristic roots, is obtained. Using the argument principle, stability criteria are derived which are necessary and sufficient conditions for asymptotic stability of the neutral systems. The stability criteria need only to evaluate the characteristic function on a straight segment on the imaginary axis and the argument on the boundary of a bounded half circular region. If there are no characteristic roots on the imaginary axis, the number of unstable characteristic roots can be obtained. The results of this paper extend those in the literature. Numerical examples are given to illustrate the presented results.