Pile-up behavior of spherical indentations in engineering materials
Additional Document Info
The spherical indentation process has been modeled by the finite element method to study the pile-up behavior of elastic-plastic materials with different degrees of strain hardening. A wide range of materials was examined characterized by different elastic moduli, yield stresses, and strain hardening exponents. The geometry of the contact impressions was examined in both the loaded and unloaded conditions. Results show that pile-up behavior in elastic-plastic materials cannot be related solely to the strain hardening exponent, as has often been done in the past. Relating the pile-up behavior strictly to the strain hardening exponent may lead to significant errors in the calculated contact area for materials with modulus to yield stress ratio lower than 1000. In addition, an assessment of the combined influences of material properties and stage of development of the contact impression on the pile-up behavior is described.