Further analysis of end effects for plane deformations of sandwich strips

Saint-Venant end effects for plane deformations of sandwich strips are investigated. For two pha:;e composite strips, with homogeneous isotropic layers that are subjected to self-equilibrated end loads, the exponential decay of end effects is characterized in terms of eigenvalues analogous to the Fadle-Papkovich eigenvalues for the homogeneous strip. An earlier study of this problem was carried out by Choi and Horgan (1978, Saint-Venant end effects for plane deformation of sandwich strips. Znt. J. Solids Structures 14, 187-195). Here we simplify and extend this analysis by using the results of Dundurs on reduced dependence on the elastic constants. The decay rate is shown to depend quadratically on the two Dundurs’ constants a,/?. Numerical results yield graphs for the decay rate in the a$ parallelogram, which are immediately applicable for design purposes. For any combination of materials in the two-phase sandwich strip, these plots allow one to determine the Saint-Venant decay length. For the case of a relatively compliant inner core, an asymptotic result shows that the characteristic decay length is much larger than that for a homogeneous isotropic strip. Copyright 0 1996 Elsevier Science Ltd.