Static and dynamic behaviour of a 3D periodic structure

Abstract

This contribution deals with the assessment of static and dynamic behavior a 3D-periodic structure. Equivalent Young and shear moduli are evaluated respectively via a spring-network calculation performed on a representative volume element (RVE)of the structure and an energy approach. To assess the accuracy of the two methods, FE simulations are performed, and tensile experiments are conducted on specimens cut out from 3D-structure panels. Results show disagreement for stiffness values along y-direction. This is thought to be due to stiffness variation between RVE's due to boundary conditions. A new analytical/numerical approach is proposed taking into consideration the presence of different types of boundary conditions on RVE's. Static results are further used as an input for FE investigations of the dynamic behavior of the structure. Two models are proposed: a) homogeneous and b) laminated models. Vibration tests are performed on different specimens and fundamental frequencies are noted. Results for both models correlate well with experimental data. However, the homogeneous model is limited to low frequencies.