Purpose <p>The main purpose of this paper is develop a semi-analytical model to use computationally efficient orthogonal beam-wise elastically restrained dynamic Timoshenko beam mode shapes in energy method for scrutinizing the accurate mode shapes of orthogonally stiffened Mindlin plates.</p> Method <p>The Dynamic Timoshenko trial functions are used in energy based semi-analytical Rayleigh-Ritz method to formulate Eigen value problem.</p> Results <p>The different aspect ratios of plate, plate thickness ratio, stiffener width ratio and stiffener height ratios are considered to demonstarte the model for various boundary conditions of plate for calculating frequency parameters and mode shapes.</p> Conclusion <p>The formation of elliptical and circular nodal patterns with a combination of chess-board like configurations for both lower and higher modes has been seen.</p>