The compressive high strain rate behavior of the base and Pμb-filled polysulfide is measured using the SHPB apparatus at 4,100/s strain rate. The weight percent of microballoons were 0, 10, 20, and 30% of base polysulfide. The peak strain values remain unaffected irrespective of the amounts of P(ibs. Both peak stress and stress rise rate decrease and half-power bandwidth of the stress pulse increased as the weight fraction of the Pub increase thereby indicating that the incorporation of Pubs in polysulfide does attenuate the stress pulse which is important for shock mitigation of structures. The peak stress reduction range from 25% to 5% for breech impact pressures of 0.16 MPa. The higher the impact pressure, the lower will be the reduction in peak stress. The stress rise rate reduces with filler content and it does not alter much with the breech pressure. The reduction in stress rise rate is of the order of 50% for many cases tested. The half-power bandwidth of the stress pulse does not show any clear trend for these experimental analyses. The dynamic stress-strain response of both base and Pub-filled polysulfide exhibited initial linear elastic region, a middle nonlinear region followed by a densification region. Polysulfide with 20 and 30 wt.% of microballoon show a kink in the stress-strain curve near a strain of about 0.63 - 0.66. The SHPB experiments revealed that both base and Pub-filled polysulfide are sensitive to strain rates over the range of strain rates studied. In all Pub filled polysulfide, the adiabatic temperature rise in the specimen at 4100/s strain rate causes material softening.
展开▼
