Efficient robust design optimization of rail bridge hollow pier considering uncertain but bounded type parameters in metamodeling framework: Fid-Bau Portal

Efficient robust design optimization of rail bridge hollow pier considering uncertain but bounded type parameters in metamodeling framework

Bhattacharjya, Soumya / Banerjee, Sanniv / Datta, Gaurav

Abstract

Abstract A robust design optimization (RDO) of rail bridge hollow pier (RBHP) under uncertainty is explored in the present paper. Uncertainty information about such structural system is often observed to be insufficient to define involved uncertain parameters probabilistically. Rather, information about bounds of the variability of these uncertain parameters is only available. In such case, parameters are modeled as uncertain but bounded (UBB) type. The conventional reliability-based design optimization cannot be applied with UBB type uncertainty. Keeping this in view, an RDO, which is a relatively newer approach, is explored for RBHP under UBB type uncertainty in the present study. The RDO minimizes cost and deviation of cost simultaneously ensuring constraint feasibility under uncertainty. Literature addressing RDO on RBHP with UBB parameters considering seismic effects is observed to be scarce. As the simulation-based approach would require a tremendous computational time, a moving least squares method (MLSM)-based metamodeling approach has been adopted here to alleviate the computational burden. The RDO results show that guarantee in safe performance and substantially reduced deviation of structural performance can be achieved by the RDO. The behavior of the structure is quite satisfactorily captured by the MLSM predictions than the conventional least squares method-based metamodeling. The computational time is observed to be drastically reduced in the present case in comparison to that by the direct Monte Carlo Simulation.