Numerical Study on the Effect of Gravity on Modal Analysis of Thin-Walled Structures

Computational modal analysis is usually carried out without consideration of gravity forces. This is well motivated for many structures. However, the vibrational properties of thin-walled plane or shallow shell structures are very sensitive with respect to small modifications of the shell geometry and with respect to in-plane stress and reinforcement. One reason for these in-plane stresses and geometric modifications consists in gravity. This becomes an important issue when using test data obtained under the presence of gravity to update a simulation model where the influence of gravity is neglected. This study investigates the influence of gravity on the modal parameters of a thin rectangular plate and of a thin-walled cubic box. For that, different simulation models are used. While all of them utilize the finite element method, linear and non-linear approaches are compared. The latter take into account geometrical nonlinearities due to large deformations and the influence of gravity induced stress. (C) 2018 The Author(s). Published by S. Hirzel Verlag. EAA.