Investigations On The Fundamental Solutions And Typical Contact Problem With Surface/Interface Effects

Nano-technical has been widely used in the surface engineering. Thesurface/volume ratio of nano-scale structures and materials are so large that thesurface/interface effects play a very important role on the mechanical properties ofthese structures. This paper investigates the fundamental solutions and contactproblem with surface energy effects.1. Based on Hankel and Fourier integral transforms technique, the axisymmetricMindlin problem and half-plane problem loaded by a concentrate force on the surfaceare studied. The fundamental solutions of elastic field of these problems are derived.The results show that surface stress has significant effects on the elastic fieldsespecially shear stresses. As far away from the surface, the influence of surface stresswill decrease. When the surface residual stress is large enough, the influence of theout-plane term is so bigger that it can’t be ignored.2. The stress and the displacement fields with interface energy effects for twojointed elastic solids subjected to an interior concentrated load are investigated in thispaper. As special cases of present results, the elastic field of the half-plane and half-space with surface effects are also presented. Numerical analyses show that theinterface energy plays an important role on the elastic fields near the interface. Theinfluence of surface stress on shear stress is much bigger than vertical stress. As faraway from the surface, the influence of surface stress will decrease.3. The problem of a elastic body indentation by a flat-ended rigid cylinder isstudied based on the proposed fundamental solutions and the dual integral equationtechnique. The results show that the surface stress has much more significant on shearstress than vertical stress. The surface energy effects have important influence on theeffective stress under the indenter.