Minimum life-cycle cost-based optimal design of yielding metallic devices for seismic loads

The yielding metallic devices have been used to improve the performance of building structures at design level intensities. They dissipate large levels of vibration energy through yielding of disposable steel plate elements but they may also enhance acceleration response related damage of mechanical and electrical components. This paper addresses the optimal design of these devices that minimizes the expected life-cycle object cost considering the story drift and acceleration related damages over the entire spectrum of seismic intensities that can occur on a building site. Genetic algorithm is used to calculate the optimal design parameters of the devices. The uncertainties associated with the frequency of occurrence of earthquakes of different intensities and random characteristics of the structural response are included in the life-cycle failure cost and the object cost calculations. It shown that these devices can be used effectively to reduce the overall life-cycle object cost and can be considered as good protective investment for structural designs in seismic regions.