The Hump Deformation Preceding a Moving Load on a Layer of Soft Material

Abstract

When a load, for instance a heavy roller, moves slowly along the surface of a solid mass of soft material, a “hump” deformation is often observed to precede it. The process of formation from an initially level surface, and the final form of hump established, are investigated analytically for a purely viscous material, in two-dimensional motion. It becomes evident that a material showing nonlinear creep, or a viscoelastic material, would show qualitatively similar behavior, the simple viscous model being adequate to exhibit the essential qualitative features.