Architected adhesive joints with improved fracture toughness
(2023) Advances in Structural Adhesive Bonding — ISBN: [9780323912143], p. 900, published
Files
35-Ch34dd.pdf
Open Access - Adobe PDF
- 6.52 MB
Details
- Authors
- Abstract
- Assembly through adhesive bonding of primary and load-carrying components often requires the use of stiff and reliable joining materials with relatively high strength. Such materials often are limited by a relatively low toughness and a high sensitivity to initial flaws and cracks. Thus, much of the focus in the structural adhesive community has been on improving the damage tolerance of bondline materials. This has been achieved through a number of strategies, including reformulating adhesives, as discussed for several adhesive families in Part I, and introducing additional phases or materials (e.g., toughening phases at the nano- and microscales that dissipate energy during failure) as discussed in Chapters 7 and 8. p0015 On the verge of the green transition, with the focus shifting toward optimized material usage, it is challenging and limiting to focus solely on adhesive chemistry and composition for improvement (e.g., because of the proprietary nature of formulations,long development times, inherent difficulty in realizing continued improvements, etc.). Hence, there is strong motivation to find extrinsic approaches based on structuring and geometry that can be used to toughen adhesive joints and applied to a broad range of materials, independent of chemistry and composition, while possibly also providing an opportunity for lightweighting. The focus of this chapter is on the use of architecture at the scale of tens to a hundred micrometers and above and is distinct from toughening strategies based on nanoscale particles and fibers [1,2]. Such architecture-based approaches have been used to realize bulk mechanical metamaterials (MM) with the goal to realize higher-performance materials, materials with unique combinations of properties, or unconventional properties (e.g., negative Poisson’s ratio). The time has come to advance such a paradigm owing to progress in manufacturing, notably digital manufacturing, in the context of adhesive bonding. Contrary to the common paradigm of material continuity and isotropy, some emerging architected materials introduce predetermined defects that allow for extra energy dissipation. These “defects,” if correctly designed, can have a beneficial effect by improving toughness without significant loss of stiffness. Note that one of the basic toughening principles is to increase plastic dissipation by designing the joint thickness to optimize the plastic zone size. This is the specific subject of Chapter 18, and the underlying principle of increasing plastic dissipation will be further exploited here through variations of this idea. In this chapter, we first review several principles that can be used to enhance toughness and then show several embodiments of these principles through architecting of joints.
- Affiliations
University of Pennsylvania Department of Mechanical Engineering and Applied Mechanics Aarhus University Department of Mechanical and Production Engineering
Citations
Pardoen, T., Turner, K. T., & Budzik, M. K. (2023). Architected adhesive joints with improved fracture toughness. In David Dillard (ed.), Advances in Structural Adhesive Bonding (2nd Edition, p. p. 900). Elsevier. https://hdl.handle.net/2078.5/228508