Abstract
Hertz contact theory was first derived 133 years ago which prescribes the contact behavior of normal contact between elastics. Furthermore, many studies and applications are based on it. However, Hertz contact theory still exists many uncertainties. This study first focused on the contact of a rigid sphere and an elastic half-space, and found that Hertz theory predicts well at large indentation. Besides, the critical contact central angle is 47.8° with maximum von Mises strain of 0.51. This large indentation result is independent of Young's modulus of the elastic half-space and the radius of the sphere, and it could be explained by the conformation of the pressure distribution at contact surface. Results were yielded by finite element method (FEM) and nanoindentation of polydimethylsiloxane (PDMS).
