Dynamic crack propagation in metals and ceramics will be studied in this experimentally oriented research program. A new and versatile experimental technique, which utilizes miniature strain gages, will be developed to evaluate a fracture parameter, the J-integral. This strain gage technique together with the established birefringent coating and caustics techniques will be used to analyze rapid crack propagation in opaque materials. This study will identify the material and structural parameters, which govern the run and arrest phenomena of a crack, for designing crack arresters in safe fail structures. Dr. Shukla will also continue his empirical modelling of crack curving and branching using photoelasticity. He will initiate a new crack branching study of 4340 steel subjected to uniaxial and biaxial loadings. Such study should lead to a better understanding of the material removal process in machining of metals and the design of armor and antiarmor devices. Although young, Dr. Shukla has already established himself as a competent and meticulous experimentalist in the field of dynamic fracture.
