@article{pearson_zikry_wahl_2009, title={Computational design of thin-film nanocomposite coatings for optimized stress and velocity accommodation response}, volume={267}, ISSN={["1873-2577"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-65949109936&partnerID=MN8TOARS}, DOI={10.1016/j.wear.2008.11.027}, abstractNote={The tailoring of thin-film coatings comprised of high strength nano-grained constituents is investigated by new microstructurally based finite-element techniques for applications related to the wear, durability, and performance of these coatings over a broad range of temperatures and loading conditions. These coatings are comprised of brittle phases, diamond-like carbon and partially stabilized zirconia and ductile constituents, such as gold and molybdenum. The effects of wear, contact transfer films, grain sizes and distributions, grain spacing and strength are used to determine the optimal thin-film coating compositions. Comparisons are made with experimental measurements pertaining to durability and wear for validation and for the development of design guidelines for thin-film nanocomposite coatings.}, number={5-8}, journal={WEAR}, author={Pearson, J. D. and Zikry, M. A. and Wahl, K.}, year={2009}, month={Jun}, pages={1137–1145} }
 @article{pearson_zikry_wahl_2009, title={Microstructural modeling of adaptive nanocomposite coatings for durability and wear}, volume={266}, ISSN={["1873-2577"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-64749097639&partnerID=MN8TOARS}, DOI={10.1016/j.wear.2009.02.004}, abstractNote={Adaptive thin-film nanocomposite coatings comprised of crystalline ductile phases of gold and molybdenum disulfide, and brittle phases of diamond like carbon (DLC) and ytrria stabilized zirconia (YSZ) have been investigated by specialized microstructurally based finite-element techniques. One of the major objectives is to determine optimal crystalline and amorphous compositions and behavior related to wear and durability over a wide range of thermo-mechanical conditions. The interrelated effects of microstructural characteristics such as grain shapes and sizes, local material behavior due to interfacial stresses and strains, varying amorphous and crystalline compositions, and transfer film adhesion on coating behavior have been studied. The computational predictions, consistent with experimental observations, indicate specific interfacial regions between DLC and ductile metal inclusions are critical regions of stress and strain accumulation that can be precursors to material failure and wear. It is shown by varying the composition, resulting in tradeoffs between lubrication, toughness, and strength, the effects of these critical stresses and strains can be controlled for desired behavior. A mechanistic model to account for experimentally observed transfer film adhesion modes was also developed, and based on these results, it was shown that transfer film bonding has a significant impact on stress and wear behavior.}, number={9-10}, journal={WEAR}, author={Pearson, James D. and Zikry, Mohammed A. and Wahl, Kathryn J.}, year={2009}, month={Apr}, pages={1003–1012} }
 @article{pearson_zikry_prabhugoud_peters_2007, title={Global-local assessment of low-velocity impact damage in woven composites}, volume={41}, ISSN={["1530-793X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-35448962064&partnerID=MN8TOARS}, DOI={10.1177/0021998307078734}, abstractNote={Global measurements from low-velocity impact experiments and local strain measurements from embedded and surface mounted optical fiber Bragg grating (FBG) sensors were used to obtain failure maps for two- and three dimensional woven composites. These maps delineated five distinct regimes spanning behavior from initial impact to complete penetration. Sensor and host damage were separated by signal intensity and the evolution of Bragg peaks due to repeated impact loads. The results indicate that a local-global framework can be used to monitor damage progression in different host materials, and hence it can be potentially used to mitigate damage.}, number={23}, journal={JOURNAL OF COMPOSITE MATERIALS}, author={Pearson, J. D. and Zikry, M. A. and Prabhugoud, M. and Peters, K.}, year={2007}, month={Dec}, pages={2759–2783} }
 @article{pearson_zikry_prabhugoud_peters_2007, title={Measurement of low velocity and quasi-static failure modes in PMMA}, volume={28}, ISSN={["0272-8397"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34250820545&partnerID=MN8TOARS}, DOI={10.1002/pc.20287}, abstractNote={An investigation of the low velocity impact and quasi-static failure of polymethylmethacrylate (PMMA) based on global and local strain measurements was conducted. Local strains were obtained from surface-mounted fiber Bragg grating (FBG) sensors, and they were combined with global measurements from quasi-static indentation and low-velocity impact experiments to obtain detailed maps of how failure evolves. For both loading regimes, the interactions between the host PMMA specimens and the sensors played a crucial role in the evolution of residual strains. A mapping of the strains clearly shows that strains decrease radially, from high values near the point of impact to far-field values. Sensors located in critical locations had the highest residual strains prior to PMMA fracture. Furthermore, it was determined that strain transfer to the sensor is strongly influenced by the bonding conditions at the specimen's surface. Because of the debonding of the sensor and the frictional effects associated with the bonding agent, compressive residual strains occurred on the rear-surface. Hence, a detailed understanding of how strain evolves due to sensor–host interactions and catastrophic fracture can be obtained, which can potentially be used to mitigate damage in PMMA for a range of strain rates. POLYM. COMPOS., 28:381–391, 2007. © 2007 Society of Plastics Engineers}, number={3}, journal={POLYMER COMPOSITES}, author={Pearson, J. D. and Zikry, M. A. and Prabhugoud, M. and Peters, K.}, year={2007}, month={Jun}, pages={381–391} }