st The21 InternationalCongressofTheoreticalandAppliedMechanics (ICTAM04) took place August 15 - 21, 2004, in Warsaw, Poland. It was organized by Polish National Committee of IUTAM, Institute of Fundamental Technological Research of the Polish Academy of Sciences (IPPTPAN)andWarsawUniversityofTechnology. TheCongressvenue was the main building of Warsaw University of Technology. The idea of congresses devoted to mechanics, can be traced back to a conference on problems of?uid mechanics in Innsbruck, 1922. It was organized by four individuals, whose names, are and will, remain very...