Creep stability of orthotropic shells with allowance for transverse shear strains

Abstract

Glass reinforced plastics are orthotropic materials whose deformation properties are described by a linear rheological relation, creep in the direction of the reinforcement being disregarded. In studying the bending and stability of plates and shells of such material it is necessary to take into account the transverse shear strains, since the shear stiffness of glass-reinforced plastics is low and is reduced even further as a result of creep. If the transverse shears are neglected, i.e., if the Kirchhoff-Love model is employed, in a number of cases of the bending of plates it is not possible to give even a qualitative description of the development of the deflections in time, since in this case we get only the elastic solution [1]. The stability of a cylindrical shell of glass reinforced plastic is investigated using the refined theory of shells [2, 3]; the instantaneous and long-time critical loads are obtained; it is shown that in certain cases using the Kirchhoff-Love model, which here gives only the instantaneous critical load, leads to substantial quantitative and qualitative errors.