SHOCK-INDUCED POLARIZATION OF PLEXIGLAS AND POLYSTYRENE,
Abstract
The theory describing the electric polarization produced in certain dielectrics by the passage of a shock front has been generalized to take account of relaxationeffects. The shock-induced displacement current is described in terms of three parameters: P sub S zero, the polarization produced at the shock front; K', the dielectric constant of the shocked material; and tau, a relaxation time. Values of P sub S zero, K', and tau have been obtained experimentally for Plexiglas and polstyrene at a number of different pressures. At the pressures where Hugoniotdata indicate phase transitions, P sub S zero and K' increase rapidly with pressure.In the same pressure range, the relaxation time decreases by nearly two orders of magnitude, indicating that molecular motion occurs more freely in the high-pressure phase. Greater freedom of molecular motion would enable the materials to be more easily polarized by both mechanical and electrical forces in agreement with the observed increase in bth P sub S zero and K' at the phase transition. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1964
- Accession Number
- AD0451774
Entities
People
- F. E. Allison
- G. E. Hauver
Organizations
- Ballistic Research Laboratory