Progressing Within Amplitude Domain Mechanical Spectroscopy : Overcame Difficulties and Remaining Questions

Abstract
Amplitude domain mechanical spectroscopy is specially interesting as it yields material response data directly in terms of stress or strain amplitudes. Critical stresses and strains are the most immediately significant parameters when material strength is the main object of investigation. On the other hand, as the phenomena are nonlinear, no full rigorous treatise of the complex question of amplitude dependent (material) damping (ADD) and modulus is presently available, as far as we know. However the existence of certain particular, reproducible features of ADD suggest that a systematic analysis of amplitude dependent damping curves (ADD curves) could be carried out by an ad hoc semi-empirical procedure. This procedure, called "parametric analysis", enables a very precise determination to be given of the various components of ADD. It is thus a means of performing amplitude domain mechanical spectroscopy. An associated model, called "moties-pinners model" proposes an outline for frequently observed phenomenology in terms of microstructural effects. We shall try here to specify which elements of the treatise can be considered as established and which still require further investigation.