It is well known that the path-independent H-integral is an appropriate tool for
calculating the mixed mode stress intensity factors for the interface corners between
dissimilar elastic materials. To extend the applicability of the H-integral from the
mechanical loading condition to the thermal loading condition, a modified H-integral
is proposed in this paper. This modified H-integral possesses an extra domain integral
which needs the input of temperature field. Moreover, this domain integral contains
singular functions that come from the strain components of the auxiliary system,
and a special treatment should be made for the accurate computation of
stress intensity factors. The near-tip solutions and auxiliary solutions of
displacements, stresses, and temperature required in the calculation of H-integral
are all provided in this paper. The validity and versatility of the proposed
approach are then shown by carrying out several numerical examples such as
cracks under mixed-mode thermal loadings, interface cracks/corners under
uniform heat flow or uniform temperature change, and an electronic package, in
which the chip has a heat generation rate, placed at a constant temperature
ambiance.
Keywords
interface corner, order of stress singularity, order of
heat flux singularity, stress intensity factor, Stroh
formalism, thermoelasticity