| Popis: |
The dynamic behavior of a homogeneous slab subjected to a short pressure pulse on one face is explored from a simple rheological point of view. The analysis is one dimensional, but involves two strain modes in the material. The early response is shown to be controlled by the bulk viscosity which influences the distortion and attenuation of propagating disturbances. In particular, the peak stress at interior points is shown to be very sensitive to the duration of the pressure. This result is quite different from that usually applied in the analysis of impact data in which it is assumed that the controlling differential equations are hyperbolic and that the density pressure relation is not time dependent. It is also more compatible with some of the experimental results. Criteria for mechanical similarity are described which may be useful in the design and development of systems subjected to impacts. The uniaxial deformation generated in this type of experiment is contrasted with the uniaxial load condition generated in the usual tensile test. In the present case, not only the wave propagation is distinctive, but the tendency toward strain homogeneity and strain stability can also be greatly enhanced. This is likely to be relevant to the understanding of material‐forming processes. |
