On the Shock Response of Polymers to Extreme Loading

Abstract

This paper reviews polymer response to shock and discusses how plastics behave differently depending on the strain rate applied. The author uses polyethylene, polytetrafluroethylene, polycarbonate and epoxy as example materials. It is suggested that there are two distinct regimes of polymer response corresponding to low and high shock pressures (weak and strong shock regimes) that must be considered separately. Above a high pressure threshold it is proposed that polymers homogenize to carbon-containing structures which behave similarly. Further, the yield stress of a polymer volume element asymptotes to the theoretical strength of the material as volume shrinks to zero. It is suggested that these two behaviours reflect the same physics and this feature is common to the condition identified earlier for crystalline materials.

The Dynamic Response of Dense 3 Dimensionally Printed Polylactic Acid

“…However, above the particle velocity of ca. 0.2 mm/μs, as recorded in this experiment, most polymeric materials give a linear response, of the form U s = C o + SU p , along with other commercially available polymers and specially produced plastics [9]. The empirical constants C 0 and S in the linear and polymeric best-fit equations are related to the bulk sound speed (in metals such as copper) [27] and the rate of change of compressibility of the material with pressure [9], respectively.…”

“…0.2 mm/μs, as recorded in this experiment, most polymeric materials give a linear response, of the form U s = C o + SU p , along with other commercially available polymers and specially produced plastics [9]. The empirical constants C 0 and S in the linear and polymeric best-fit equations are related to the bulk sound speed (in metals such as copper) [27] and the rate of change of compressibility of the material with pressure [9], respectively. More striking, and in line with other polymeric materials such as PMMA, and polycarbonate [8], is the failure of the experimental data to extrapolate to the zero-pressure ultrasonic measurement as observed in metals.…”

“…The values of the c 0 and S in the Hugoniot equations are empirical constants, correlated to the bulk sound speed c B and the first pressure derivative of the bulk modulus respectively [9].…”

A theoretical model for the electromagnetic radiation emission from hydrated cylindrical cement paste under impact loading

“…where m and v o are mass and velocity of the striker. Polymeric materials are known to absorb energy during impact and dynamic loadings which leads to their usage in different areas [56][57][58]. Bakelite is a polymer categorized as a thermoset plastic and elastic modulus of polymers generally lies in the range of 3450 MPa [59] which is less than elastic constant for cement.…”

Celebrating 75 Years of the Society for Experimental Mechanics and the Study of Dynamic Behavior of Materials

“…The journal is highly international, publishing experimental and theoretical studies of metals [57], polymers [58], glasses [59], composites [60], granular materials [61], explosives [62], biological materials [63], geological materials [64], phase transitions [65], and structural response [66]. The journal includes application and development of techniques including split Hopkinson pressure bar/Kolsky bar [67], plate impact with light gas guns and powder guns [68], Taylor Anvil [69], Dynamic-TensileExtrusion [70], spectroscopy-and pyrometry-based shock temperature measurements [71], optical and X-ray imaging methods [72], interferometry and velocimetry techniques [73], dynamic fracture [74], laser based dynamic drivers [75], penetration and ballistics [76], equation of state [77], and spall failure [78].…”