TWINNING PROGRAM WITH GEORGIA, ROMANIA, AND UKRAINE

Nicolae Cristescu visited Romania twice in 1999. There he began work with Eugen Soos and Ionel Molnar, Romanian Academy Institute of Mathematics, on the formulating a geomechanical model of a nonassociated elasto/viscoplastic type, developing the method elastic predictor--plastic corrector, devising stability theorems, and obtaining numerical results for selected constitutive equations. All report they have benefited from working together. Cristescu has updated his colleagues on the latest developments regarding the geomechanical constitutive equation, and in the coming year his colleagues will have the chance to travel to the U.S. and work with better computers and better scientific information. The research that is being carried out by this team may have direct impact on solving problems related to storage of radioactive waste, deep drilling, and storage of gases and liquids in underground caverns and deep tunnels. Soos and Molnar have plans to travel to the U.S. in May 2000 and in Fall 2000 to prepare a paper on results of the research conducted over the past year.

Update--2000

Soos and Molnar arrived in Gainesville in May 2000, with the former staying for one month and the latter for two months. Thanks to the superior high-performance computer provided for their use at the University of Florida, they were able to make significant progress on the numerical aspects of their project, including analysis of the various numerical algorithms and comparison of various approximations to be used in conjunction with finite elements. In November 2000, Cristescu spent ten days in Bucharest working with his colleagues on the text of a paper summarizing their results. Cristescu notes that "the results obtained are but a starting point in a big effort to implement new constitutive equations in reliable numerical codes. These constitutive equations are important also for the new emerging micro- and nanotechnologies, of great interest at the University of Florida and generally in the United States." This research team has received a no-cost extension to continue their work into 2001, with Cristescu to visit Bucharest in March and Molnar to return to Gainesville in April.

Dr. I. Molnar (right) and Professor I. Soos working in May 2000 at the computer

supplied by the University of Florida.

Update--2001

In March 2001, Cristescu made his planned visit to Bucharest to continue work on the joint paper he and his Romanian colleagues started last year. Molnar returned to Gainesville May 15-June 15, 2001, to finalize the computations needed for the paper, which is now complete and ready for submission to a major journal. Cristescu reports that on the basis of the encouraging results he and his partners have obtained during their Twinning project, they expect to continue their collaboration. Their work will center on implementing new mathematical models describing the mechanical properties of particulate materials into numerical codes, as well as solving important related technological problems. The American side will focus primarily on experimental aspects and on the formulation of the constitutive equations, while the Romanians will concentrate mainly on the numerical approach and on the implementation in numerical codes.