Inertial Impact Tests to Identify the Plastic Properties of Metals

Abstract

The behavior and failure mechanisms of materials often change at high strain rates (> 100 1/s) when compared with their quasi-static response. These differences are critical when designing structures or components that will be subjected to impact or blast loads. The recent progress in ultra-high speed imaging and full-field measurement techniques provides a unique opportunity to improve the quality of high strain rate test data. The objective of the current work is to design and validate an experimental technique to identify the elastoplastic material properties of metals. The methodology uses an ultra-high speed camera and the grid method to obtain time-resolved full-field deformation data as impact induced stress waves propagate in a sample. The virtual fields method is then used to inversely identify the plastic properties of the specimen. The results for five aluminum 6082-T6 impacted at 50 m/s are presented.