Confined compression: A stable homogeneous deformation for constitutive characterization

An experimental configuration is described in which the complete state of s tress and strain in the specimen are determined through direct experimental measurement, without a priori constitutive assumptions with regard to the material behavior. Moreover, the control of the deformations is such that t he deformations are always stable. Design considerations in implementing su ch an experimental configuration and applications to the investigation of t he multiaxial constitutive behavior in materials are also described. An exa mple of the implementation is demonstrated using Al 6061-T6 alloy.