I have modelled thermal stresses in orthogonal machining using the elastic thermal stress theory of Timoshenko and Saif's Green functions. But, I get very strange results at the surface of the workpiece i.e. the stresses at the very top surface layer are abnormally high as compared to those on the underlying layers, even the very next layer. I believe that these might be due to wrong definition of boundary conditions related to temperature differentials or there is a possibility of a computational error as well.
Can some one help me resolve the issue.
Thank you.