A rate-independent internal friction to describe the hysteretic behavior of pantographic structures under cyclic loads. (September 2021) - Ciallella, A.
Abstract: The cyclic behavior and dissipative properties of pantographic fabrics are analytically and experimentally investigated in this paper. To these purposes, a two-dimensional second-gradient continuum model, already developed in the literature, is taken as representative of the elastic behavior of the homogenized system. However, to take into account the dissipative phenomena, the model is enriched with a suitable Dahl-like phenomenological dissipation law, accounting for friction effects at the interconnecting pivots, that it is shown to be effective in describing the macroscopic hysteretic behavior under cyclic and quasi-static imposed displacement time-histories. Numerical results are compared against experimental ones, thus showing the effectiveness of the continuum model in reproducing the real behavior of pantographic fabrics. Highlights: Pantographic fabrics show a macroscopic hysteretic behavior if undergoing cyclic loads. A second-gradient model and a Dahl-like dissipation well capture the cyclic behavior of it. An excellent agreement between the experimental and the numerical results is observed. A remarkable effect due to the second gradient energy contribution is recognized. This result corroborates the use of a second-order grade continuum for such structures. The dissipated energy per cycle, theoretically evaluated, is confirmed by experiments.