by ROMAN TEISSEYRE
Institute of Geophysics, Polish Academy of Sciences
The paper introduces a new model of earthquake processes based on the theory
of micromorphic continua. The processes in a focal region are described by
deformations of microstructure in time.
It is assumed that the fracturing processes as well as phase transformation
or metamorphic phenomena have caused in the past certain non-reversible changes
in the Earth material which determine the microstructure of the focal region.
These internal microstructural elements form the attaching points around which
the couple stresses arise. The properties of focal region are determined by
the constitutive equations.
The micromorphic mechanics considers the existence of body couples as determined
by regional stresses and looks after a response field of stresses, stress moments
and strains in the focal region. Further, it is explained how the microdislocation
field is connected to microdeformations and the micromorphic structure.
It is considered earthquake structure model a microanisotropy is assumed through
the tensor of microinertia. This tensor describes a distribution of microelements.
Simple solutions of wave processes in a focal region are presented. The dispersion
of waves is discussed.