On the direct determination of invariant parameters governing anisotropic plate bending problems Pages 3969-3982

Many papers deal with the determination of flexural rigidities of anisotropic plates from only one specimen subjected to one or several loading conditions. In such a problem, one of the main questions is the best identification of the unknown parameters according to the type of material, the shape of the specimen and the loading conditions. It seems that no general rule giving the “best” configuration leading to an accurate determination has been established. One of the main reasons is the anisotropic nature of the tested plates. which leads the mechanical configuration to be dependent on the material itself. This problem would be avoided by the direct measurement of invariant parameters from which the rigidities are easily deduced. These invariant parameters reveal the intrinsic elastic behavior of the tested plate, contrary to the rigidities usually considered which are directional quantities. This paper describes a procedure for the identification of invariant parameters governing the bending of anisotropic plates. It is shown that the whole displacement field processing of the surface strain fields obtained in two particular loading cases directly provides those parameters. A numerical simulation shows the stability of the present method. Copyright PI 1996 Elsevier Science Ltd