RESEARCH
EXPERTISE AND INTERESTS

• solid mechanics
• fracture mechanics
• novel / non-traditional materials

- functionally graded materials (FGM)

- sandwich structures

- nanocomposites

- multifunctional materials

- electronic materials

- syntactic foams

- interpenetrating phase composites (IPC)

- interpenetrating polymer networks (IPN)

• photomechanics / optical metrology
• NDE
• optical/digital image processing

RESEARCH SUMMARY

Dr. Tippur's research broadly deals with (a) failure mechanics of advanced materials using experimental and computational methods and (b) development of optical sensors. Over the years he has developed novel techniques based on laser speckle and geometric moiré methods for mapping three-dimensional deformations near cracks in ductile materials. He is credited with the development of a novel real-time optical method called Coherent Gradient Sensing (CGS), suitable for dynamic fracture studies when used in conjunction with ultra-high speed photography. The method has since found application for characterizing thin film/structures as well.  Dynamic fracture mechanics of polymers, high strength steels and dissimilar material interfaces have been successfully studied using this new tool. Recently, an infrared interferometric sensor has been developed to perform rough surface metrology and flaw detection. The sensor is successfully used for real-time fracture mechanics studies on plastically deformed ductile homogeneous materials and bi-material (solder-copper) interfaces. In recent years they have also successfully extended the method of digital image correlation (DIC) to study fast-fracture events under shock loading conditions using digital high-speed imaging systems. His current interests include development and failure characterization of emerging materials such as functionally graded materials and porous/micro-cellular materials for thermal barrier coatings, light-weight structures, and surface engineering. Modeling the failure behavior using finite element method and boundary element method is integral to many of his research projects.  His research is sponsored by NSF, ARO, NASA and AFoSR. Dr. Tippur has published over 150 research articles in refereed journals and conference proceedings.