Static deflections and natural frequencies of vibrations are obtained for blade-stiffened plates using a three-dimensional model for the plate and a two-dimensional (plane stress) model for the stiffener with simply supported edge/end conditions. These are used as a benchmark for assessing the approach based on the classical hairbrush hypothesis. Results obtained by using the rigorous elasticity model for the plate alone or the stiffener alone are also presented. These results indicate the greater importance of non-classical effects in the analysis of stiffened plates as compared to unstiffened plates. © 2014 Elsevier Ltd. All rights reserved.