The analytical solution of three-dimensional heat conduction problem,
including the temperature and thermal flux fields, is one of the important
problems that have not been completely solved in solid mechanics.
Considering the temperature dependence of material parameters makes the
problem more difficult. In this paper, we first reduce the three-dimensional
temperature-dependent heat conduction problem to the solution of
three-dimensional Laplace equation by introducing the intermediate function.
Then, the generalized ternary function is proposed, and the general solution
of three-dimensional Laplace equation is given. Finally, the analytical
solutions of three specific problems are obtained and the corresponding
temperature-thermal flux fields are discussed. The results show that the
thermal flux field of three-dimensional temperature dependent problem is the
same as the classical constant thermal conductivity approach result, while
the temperature field is different from the classical result. Thermal flux
at a planar defect boundary has r-1/2 singularity, and its intensity is
proportional to the fourth root of defect width. On the other hand, when
blocked by a planar defect, the thermal flux distribution will re-adjusted
so that it overflows at the same rate from all parts of the planar defect
boundary.