Refined Structural Theories for the Random Response of Fiber-Reinforced and Sandwich Composite Structures

This paper presents numerical results concerning the structural dynamics of aerospace structures undergoing random excitations. The focus is on using refined structural models to investigate the accuracy of lower-order – Euler-Bernoulli and Timoshenko – and higher-order theories and, thus, determine the influence of some typical structural features, such as the shear deformation and warping. The numerical examples consider typical loadings with a random nature, white and jet noises, and gusts being common cases. The solution scheme is based on the finite element approach and the use of power and cross-spectral densities. The results are provided in the frequency domain using spectra and root mean square values of displacements and stresses. The results prove the ability of refined models to capture the dynamic responses at low and high frequencies. Moreover, as 1D models have superior computational efficiency compared to 2D and 3D ones, the proposed framework may have interesting perspectives in demanding analyses such as those concerning the fatigue life determination of complex aerospace structures.