Non-convntional effects in stressed structural materials

Evidences for non-conventional reactions in materials subjected to stress are collected in the last years either during ultra sound irradiations or under the effect of mecanichal presses. the microsctructural properties of the material play a fundamental role of their occurrence. In particular, small cavities of suitable size are suggested to act as micro-reactors. These reactions are not easy to explain at the light of the to-day commonly accepted theories but they can find an explanation in the framework of a theory predicting local deformation space-tima at microscopic level, when suitable conditions occur.