Mechanical Identification of Composites

The widespread idea that composite materials are materials which can be tailored toachieveanydesired structuraland functional performances iswrong, since the present commonly used mechanical characterization and designing procedures do not incorporate the two prominent features of these materials, their anisotropy and heterogeneity, from the starting point of the analysis. Anisotropy and heterogeneity involve particular effects, at different scales of observation, that cannot be regarded as simple extensions ofany phenomena occurring in homogeneous or isotropic media. So the challenge is real and further industrial applications ofcomposite!> are closely related to new ways of approaching theexperimentalidentification ofsuch materials orstructuresin the rational frameworkofthe mechanicsofheterogeneousandanisotropic media. The European Mechanics Committee sponsored a Colloquium on Experi mental Identificationofthe Mechanical CharacteristicsofCompositeMaterials and Structures in Saint-Etienne, France, on 3-6 December 1990. Its main purpose was to present, criticize and survey new developments in analysis techniques, data treatments, mechanical modelling and identification approaches regarding the anisotropic behaviour ofcomposite structures. The fourty nine papers, including the general lectures, touched four main aspects: . quasi-static and dynamic mechanical tests suited to anisotropic media; . identification methodologies based on new data treatments; . displacement and strain fields measurement based on optical methods; . damage and cracking modellingofanisotropic and heterogeneous media.