Effects of high and low temperature on the dynamic performance of the core material, face-sheets and the sandwich composite

Abstract

The performance of sandwich structures is highly affected by the varying environmental temperature during service, especially when they are subjected to blast loading. Typically, sandwich panels consist of polymer based composites (face-sheets) and polymer foams (core material), and the properties of its components change substantially under different temperatures. In this paper, high strain rate constitutive behavior of E-glass Vinyl ester composites and Corecell™ M100 foam at different temperatures has been studied. A special temperature control chamber was designed in order to heat or cool the specimen to an assigned temperature. Once the specimen reached the target temperature, it was subjected to high strain rate loading using a SHPB apparatus. Eight different target temperatures were chosen: -40°C, -20°C, 0°C, 22°C, 40°C, 60°C, 80°C and 100°C. The sandwich composites were maintained at the target temperature before being subjected to shock-wave loading using a shock-tube. A high-speed photography system utilizing Digital Image Correlation (DIC) was used to record the real time deformation of the specimen. The results show a significant decrease in flow stress with the increase in the temperature of core material. Significant fiber-matrix delamination was observed in face-sheets at elevated ambient temperatures with little change in the value of compression modulus. For the low temperature environment, the core material shows brittle behavior resulting in core-cracking of the sandwich specimen under blast loading.