Dynamic strength tests published in literature have been analysed by structuraltemporal damage criteria. Parameter τ - incubation time - describing material stability behaviour under high-rate influences have been estimated for Kimachi sandstone, Inada granite and Tage tuff. Two types of dynamic tensile experiments have been used: split Hopkinson pressure bar and spalling. Purely dynamic effect of fracture delay have been observed in the case of Kimachi sandstone and discussed