The effect of strain rate on the mechanical behavior of Teflon foam

Abstract

a b s t r a c tThe quasi-static (1 Â 10 À3 , 1 Â 10 À2 and 1 Â 10 À1 s À1 ) and high strain rate (7200 and 9500 s À1 ) experimental and high strain rate numerical compression deformation of a Gore PolarchipÔ CP7003 heat insulating Teflon foam was investigated. High strain rate tests were conducted with the insertion of quartz crystal piezoelectric transducers at the end of the transmitter bar of a compression Split Hopkinson Pressure Bar (SHPB) set-up in order to measure the force at the back face of the specimen. A fully developed numerical model of the SHPB test on Teflon was also implemented using LS-DYNA. The simulation stresses showed close correlations with the experimentally measured stresses on the bars. The developed model successfully simulated the high strain rate loading. The damage initiation and progression of experimental high strain rate tests were further recorded using a high speed camera and found to be very similar to those of the simulation high strain rate tests.

Dynamic Stress-strain Compressive Response of Soft Tissue using Polymeric split- Hopkinson Pressure Bar

“…The equations (9) and 10 10Lastly, the equations (9) and (10) are solved using inverse Fourier transforms, and used together with equations (2) and (3) to determine the stress-strain histories induced in the test specimen due the impact loading.…”

“…The conventional SHPB method with some modifications has been used in soft tissue characterization. These include use of most sensitive piezoelectric gauges, use of hollow transmission bars instead of solid bar, use of viscoelastic bars having less impedance, and application of pulse-shaping method [9][10][11][12]. An additional challenge is the selection of proper experimental method to characterize the soft materials from quasi-static to intermediate strain-rates in an automobile crash and higher strain-rates in impact loading.…”