The in-plane problem of a Griffith crack in a biaxially loaded degenerate orthotropic medium

In this paper a general and rather simple approach is proposed in order to study elastostatic plane problems for an orthotropic medium whose stiffness matrix has repeated eigenvalues. This method, which is based on the decomposition theorem of linear algebra, allows to obtain a complex variable formulation of fundamental equations of plane elasticity for a degenerate orthotropic medium. After that the equations so obtained are applied to study the problem of a Griffith crack embedded in the orthotropic medium subjected to a uniform biaxial load at infinity.