The eigenvalue problem about a nonhomogeneous semi-infinite strip is investigated
using the methodology proposed by Papkovich and Fadle for homogeneous plane problems. Two
types of nonhomogeneity are considered: (i) the elastic modulus varying with the thickness coordinate
x exponentially, (ii) it varying with the length coordinate y exponentially. The eigenvalues
for the two cases are obtained numerically in plane strain and plane stress states, respectively. By
considering the smallest positive eigenvalue, the Saint-Venant Decay rates are estimated, which
indicates material nonhomogeneity has a significant influence on the Saint-Venant end effect.