An Adaptive Framework for Robust Structural Shape Optimization under Uncertainty

Abstract

This work presents an adaptive framework for solving a robust structural shape optimization problem governed by linear elasticity with uncertain loading and material parameters. A posteriori error estimators are constructed to control the sample size, mesh resolution, and optimization step length. The sample size used in the stochastic gradient approximation is adjusted dynamically according to the variance of the sampled shape derivatives. In the physical domain, the proposed error estimation strategy accounts not only for discretization errors in the elasticity constraint but also for errors arising from the discretization of the deformation problem used to compute descent directions. The optimization step length is determined adaptively through an estimate of the Lipschitz constant of the stochastic shape derivative. Moreover, existence results and a distributed representation of the stochastic shape derivative are established. Finally, the proposed adaptive stochastic optimization framework is validated on leg-like structural components, demonstrating its effectiveness in minimizing touchdown compliance under uncertain contact forces.