Research and training have been extended to include the conduct of collective research: direction or co-direction of laboratories (CNRS Laboratory of Mechanical Properties and Thermodynamics of Materials at the University of Paris-XIII from 1981 to 1989, Solid Mechanics Laboratory at the École Polytechnique from 1991 to 2000); creation and direction of federative research structures (FIRTECH Île-de-France Mechanics and Materials Pole from 1985 to 1993, Île-de-France Federation of Mechanics (materials, structures and processes), CNRS, from 2003 to 2008); national research activities (management of the Pôle national de recherche technologique en mécanique et matériaux from 1991 to 1995, CNRS mission leader from 1983 to 1989) and participation in national bodies responsible for research forecasting and orientation in various fields (materials, supersonics, aeronautics and space, nuclear materials ); organisation and chairmanship of international symposia, schools and congresses (EUROMECH 183 symposium in 1984, advanced course at CISM in 1985, IUTAM symposium in 1995, etc.