In April 2007, Professor Aditi Chattopadhyay was awarded a $545,200 grant from the Air Force Office of Scientific Research jointly with co-PIs, Pedro Peralta and Jun Wei. This project is under the auspices of the Defense University Research Instrumentation Program (DURIP), and involves studying how structural fatigue in metallic materials begins and spreads. A 100 kN planar bi-axial and 10 k in-lbf (1100 N-M) torsional test system will be operational in the summer of 2008. The test system includes four independent precision controlled actuators mounted in-plane and perpendicular to one another, and can be used to conduct bi-axial fatigue test with varied non-proportional loading ratios. The added torsional loading capability allows for multi-axial tension/torsion cyclic tests. Applications include 2-D material properties and stress state characterizations at strain rate below 1 s-1, 2-D low and high cycle fatigue and crack initiation and growth studies. Materials that can be tested include advanced composites and other aerospace materials.