The International Union of Theoretical and Applied Mechanics (IUTAM) was formed in 1946 with the object of creating a link between persons and national or international organizations engaged in scientific work (theoretical or experimental) in mechanics or in related sciences. It does so mainly by organizing international meetings to deal with scientific problems. An International Congress, including mini-symposia and prenominated sessions, is held every four years with unrestricted participation, and between five and ten specialized Symposia with invited participants are held every year. These IUTAM Symposia are sometimes held in cooperation with other Unions in the ICSU family or with organizations affiliated to IUTAM. At present 51 members adhere to IUTAM.