a Department of Physics, University of Bologna, Via Irnerio 46, 40126, Bologna, Italy;b DISTART, University of Bologna, Viale Risorgimento 2, 40136, Bologna, Italy
Abstract:
In this paper the Mode-I elastodynamic problem of a crack propagating in an orthotropic medium is studied under the condition that the matrix of elastodynamic coefficients has repeated eigenvalues. It is shown that the crack is constrained in an elastodynamic state which is defined through a compulsory condition coupling its velocity with the elastic parameters of the orthotropic medium. The dynamic stress and displacement components ahead of the crack tip as well as the energy release rate are explicitly obtained.