Robust Multi-Length Scale Deformation Process Design for the Control of Microstructure-Sensitive Material Properties

Abstract : The objective of this work was to develop a robust design methodology for optimizing microstructure-sensitive properties in aircraft components manufactured using metal forming processes. The multi-scale forming design simulator developed provides means to select the sequence of deformation processes, design the dies and preforms for each process stage as well as the process conditions such that a product is obtained with desired shape and microstructure. Modeling of uncertainty propagation in such multi-scale models of deformation is extremely complex considering the nonlinear coupled phenomena that need to be accounted for. The work addresses key mathematical and computational issues related to robust multi-scale design of deformation processes. Our research accomplishments include development of new mathematical models based on spectral polynomial chaos, support space, and entropy maximization techniques for modeling sources of uncertainties in material deformation processes. These models, in conjunction with multi-scale homogenization models, allow simulations of the effect of microstructural variability on the reliability of macro-scale systems. We have developed the first stochastic variational multi-scale simulator with an explicit sub-grid model, a robust deformation process simulator using spectral and collocation methods for simulating uncertainties in metal forming processes. Finally, recent developments including an information theoretic framework for modeling microstructural uncertainties is summarized.