MULTI-OBJECTIVE SHAPE OPTIMIZATION OF STEEL SHEAR PANEL DAMPERS

Shear panel dampers (SPDs) have stable energy dissipation capacity as well as low material and fabrication cost (Deng et al., 2015). Along with the recent evolutions in computer technology and numerical analysis methods, the implementation of optimization algorithms in a wide range of engineering mechanics problems is substantially increased. Hedayat (2015) employed optimization algorithms and finite element updating methods to improve the cyclic behavior of slit dampers. Liu and Shimoda (2013) implemented shape response surface method (RSM) to improve plastic strain distribution of SPDs under cyclic loading. The edges of samples were assumed to be parabolic and the optimal parameters for the parabola were obtained using regression analysis. The results showed that edge shape optimization can be considered an effective approach to improve the cyclic performance of SPDs. Tabu Search (TS) optimization approach is used in this study. According to Figure 1-a, the horizontal location of Nequally spaced control points on the side edges of SPD are considered as independent design variables to acquire the optimal shape of the energy dissipation device. The free boundaries on the sides of the plate pass through all the control points with straight lines between every two adjacent points. In spite of studies mentioned before, two objective functions are considered in this study: Maximizing the energy dissipated by the inelastic deformation of SPD model, E(X), and the number of tolerated cycles Nf (X) before the maximum equivalent plastic strain (PEEQ) among the entire plate reaches the value corresponding to failure of SPD model (PEEQmax).

Keywords:

Low-cycle-fatigue , Shear panel damper , Tabu search , buckling , Finite element analysis