TY - JOUR
T1 - High strain rate compressive behavior of epoxy LY 556
T2 - Radial constraint effect
AU - Pothnis, Jayaram R.
AU - Ravikumar, G.
AU - Joshi, Makarand
AU - Akella, Kiran
AU - Kumar, Santosh
AU - Naik, N. K.
PY - 2012/3/15
Y1 - 2012/3/15
N2 - A projectile impacting onto a target is a typical loading case. For the analysis of such cases, knowledge of high strain rate behavior of target materials is essential. Split Hopkinson pressure bar (SHPB) apparatus is generally used for evaluating the high strain rate behavior of materials. In conventional SHPB testing, the diameter of the incident and the transmitter bars is larger than the diameter of the specimen allowing for the radial expansion of the specimen due to Poisson's effect under compressive loading. However, in practical cases, the contact area of the projectile striking onto a structure is much smaller than the surface area of the structure. In such cases, radial expansion of the structure at the point of impact is constrained by the surrounding material. Materials may behave differently in the presence of radial constraint. The objective of the present study was to evaluate the effect of radial constraint on high strain rate properties of epoxy LY 556 using compressive SHPB apparatus. Two types of arrangements were used for providing radial constraint: (i) specimen with larger diameter than the diameter of the incident and the transmitter bars, (ii) specimen with diameter equal to the diameter of the incident and the transmitter bars with a metallic holder providing radial constraint. Epoxy LY 556 specimens were tested over a range of striker bar impact velocities. It was observed that the resistance of the specimen under compressive loading increases with radial constraint. Photographs of the fractured specimens and the schematic representation are also presented. The results of the earlier work have been found to be inline with the findings made in the present study.
AB - A projectile impacting onto a target is a typical loading case. For the analysis of such cases, knowledge of high strain rate behavior of target materials is essential. Split Hopkinson pressure bar (SHPB) apparatus is generally used for evaluating the high strain rate behavior of materials. In conventional SHPB testing, the diameter of the incident and the transmitter bars is larger than the diameter of the specimen allowing for the radial expansion of the specimen due to Poisson's effect under compressive loading. However, in practical cases, the contact area of the projectile striking onto a structure is much smaller than the surface area of the structure. In such cases, radial expansion of the structure at the point of impact is constrained by the surrounding material. Materials may behave differently in the presence of radial constraint. The objective of the present study was to evaluate the effect of radial constraint on high strain rate properties of epoxy LY 556 using compressive SHPB apparatus. Two types of arrangements were used for providing radial constraint: (i) specimen with larger diameter than the diameter of the incident and the transmitter bars, (ii) specimen with diameter equal to the diameter of the incident and the transmitter bars with a metallic holder providing radial constraint. Epoxy LY 556 specimens were tested over a range of striker bar impact velocities. It was observed that the resistance of the specimen under compressive loading increases with radial constraint. Photographs of the fractured specimens and the schematic representation are also presented. The results of the earlier work have been found to be inline with the findings made in the present study.
KW - Epoxy LY 556
KW - High strain rate
KW - Radial constraint
KW - Split Hopkinson pressure bar
UR - http://www.scopus.com/inward/record.url?scp=84862778891&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2012.01.032
DO - 10.1016/j.msea.2012.01.032
M3 - Article
AN - SCOPUS:84862778891
SN - 0921-5093
VL - 538
SP - 210
EP - 218
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
ER -