Optimizing the seismic resilience performance of steel truss bridges by maximum energy dissipation via friction dampers

The primary aim of this study is to propose an innovative design methodology for optimizing the seismic resilience performance of steel truss bridges by dissipating the maximum input seismic energy. Maximum seismic energy dissipation is carried out by means of Pall friction dampers (PFDs), popularly categorized among passive energy-damping devices. PFDs distribute input seismic energy with a slip motion along with friction during an earthquake. For that, it is important to determine the optimal slip load value for the PFDs to start working before the structural elements reach the yield point. To determine the optimal slip load values of the PFDs under earthquake effects, the maximum seismic energy distribution is assured by nature-inspired Squirrel Search (SS) and Water Strider (WS) metaheuristic algorithms for steel truss bridges equipped with PFDs. Finally, steel truss bridges on which PFDs with optimal slip load values have been implemented are optimally designed to achieve the minimal structural weight while satisfying ASD-AISC Code of Practice requirements. In order to demonstrate the validity of the proposed design methodology, two design examples of 113-member and 465-member steel truss bridges steel are presented. The optimal slip loads attained with the SS and WS algorithms by conducting the proposed design methodology are 2.45% and 3.75% of the structural weight for the first design example and 2.64% and 2.63% of the structural weight for the second design example, respectively, which are much lower than those considered in practical applications. Moreover, the numerical results show that by 93.5% and 99.48% maximum distribution rates of input seismic energy are accomplished in the bridges. The results indicate that the proposed design methodology exhibit superior performance in optimizing the seismic resilience performance of steel truss bridges by maximum energy dissipation via friction dampers.