The International Centre for Advanced Materials (ICAM) and the Henry Royce Institute invite you to a hybrid seminar featuring Professor John Lambros, Willett Professor of Engineering in the Department of Aerospace Engineering at the University of Illinois Urbana-Champaign. He is currently a Distinguished International Associate of the Royal Academy of Engineering.
Professor Lambros’ talk will be held on Tuesday 23 June 2026, 3:30 to 4:30pm BST (9:30 – 10:30am CDT, 7:30 – 8:30am PDT) in Room 3A.052, Nancy Rothwell Building at The University of Manchester.
This seminar will be of interest to researchers and students working in materials science, mechanics, and related fields, particularly those interested in deformation, fatigue, and microstructural modelling.
Refreshments will be available after the seminar, with an opportunity for informal discussion for those attending in person.
Register to attend
Abstract
Under deformation the heterogeneous microstructure of polycrystalline metals generates locally complex strain variations at the microscale. The details of the strain variations may depend upon microstructural characteristics (e.g., grain size and morphology, grain boundary types, grain orientation, etc.) and loading type (e.g., tensile/compressive/shear, creep, fatigue, fracture etc.).
These local strain variations often ultimately control failure mechanisms since plastic strain tends to accumulate persistently once formed. To measure in detail such local strain variations we employ a high-resolution digital image correlation technique (HR-DIC) in which rastered digital images are stitched together to provide an ultra-high-resolution image for use in DIC codes. The method is applied to metallic materials, both traditionally and additively manufactured, under conditions of plastic cycling, elastic fatigue, and elastic or plastic creep. For modelling this response, we use machine learning (ML) methods to develop a capability for predicting microstructural-level strains. To obtain much larger datasets than HR-DIC can provide, we use numerical datasets generated by crystal plasticity finite element simulations (CPFEMs) to train a fully convolutional network (FCN). Two-dimensional patterns of plastic strain field variations (output) are predicted from grain orientation information (input) at the microscale across a large subset of grain morphologies. Previously applied FCN architectures have predicted the general patterns of plastic strain distributions, but with accuracies that saturate quickly with increasing size of the training dataset. We overcome this limitation by augmenting the traditional convolution architecture with modern architectural elements such as skip connections, depthwise separable convolutions, residual functions, and inverted bottleneck convolution modules, reducing the number of trainable parameters and floating-point operations by 88% and 77%, respectively. Our FCN architecture, trained on predominantly equiaxed grains with a fixed (lognormal) distribution of grain sizes under a small subset of macroscopic strain states, is capable of interpolation and limited extrapolation to other strain states. Its ability to predict the microscale strain patterns across a wide range of grain sizes, grain distributions, and grain shapes without retraining, further suggests its generalizability to different grain architectures. Finally, we discuss the utility of transfer learning to reduce the amount of training data required to adapt the FCN to materials with different stress–strain response.
About Professor Lambros
Professor Lambros is the Donald B. Willett Professor of Engineering in the Aerospace Engineering Department of the University of Illinois Urbana-Champaign. He received a BEng degree in Aeronautics from the Imperial College of Science and Technology, London, in 1988. He then spent several years at the Graduate Aeronautical Laboratories at Caltech, Pasadena CA, obtaining an MS and a PhD in Aeronautics in 1989 and 1994, respectively. In 1995 he joined the Mechanical Engineering department of the University of Delaware as an Assistant Professor and subsequently the Aerospace Engineering department of the University of Illinois at Urbana-Champaign in 2000 as an Associate Professor, where he became a full professor in 2007. He has served as Director of the Grainger Engineering College’s Advanced Materials Testing and Evaluation Laboratory (AMTEL) during 2018-2022 and as Associate Head for Graduate Studies in Aerospace Engineering during 2011-2016. He has also served as Vice-President, President Elect, and President of the Society for Experimental Mechanics between 2017-2020. He is a Fellow of the American Society of Mechanical Engineers (ASME), the Society for Experimental Mechanics (SEM) and the American Academy of Mechanics (AAM), and an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA). He has served as Associate Technical Editor for the ASME “Journal of Applied Mechanics”, the SEM journal “Experimental Mechanics”, and currently serves as Editor-in-Chief of “Engineering Fracture Mechanics”.
June 23 2026
