MEAM Seminar: “Mechanics- Informed Optimization for Enhanced Adhesion and Toughness”

Structural design optimization has long played a crucial role in engineering, often with the goal of creating stiff and lightweight structures for aerospace and other applications. However, optimizing structures against failure is also crucial and has been much less well explored. Failure via fracture and at interfaces is particularly challenging in design optimization as they involve high local stress concentrations and singular stresses. In this talk, we demonstrate how mechanics models can be integrated with optimization schemes to engineer structures with improved interface adhesion and fracture toughness. Specifically, four distinct structural design cases are considered: adhesive fibrils, shear lap joints, architected adhesive joints, and adaptive mechanical networks. The computational framework couples finite element analysis with multiple optimization methods, including gradient and heuristic-based techniques, as well as machine learning-based approaches. We show that performance can be improved by formulating optimization schemes and objective functions based on the principles of mechanics and failure. Optimal designs are determined via the computational schemes and validated via experiments on several different material systems. The versatility of the computational and optimization schemes that have been developed enables them to be extended to other scenarios where performance can be improved by optimizing geometry to control stresses.