Mechanics of Interfaces and Adhesion

ABOUT THE RESEARCH GROUP

God made the bulk; the surface was invented by the devil …”- Wolfgang Pauli. We are devil's advocate trying to shape properties of layered materials by design of surfaces and interfaces between constituents. Can we make a layered material more compliant or stiff only by design of interfaces? Can the damage tolerance be improved? Can layered material detect own flaws? When material fail?…why? and how? Answers will allow safter, multifunctional, stronger, lighter or smart materials to be proposed.

INTERFACE CRACK GROWTH PHENOMENA

We have, what we believe is, a fresh look on fracture along interfaces. In our approach 'cracks' are geometrical features and as such can be controlled, tuned and manipulated leading to an increase in overall material properties (physical, mechanical) and/or new functionalities (incl. aesthetics). We address most of the problems using experimental, theoretical and numerical frameworks. We are rooting to the known principles of physics and mechanics and enrich them with original findings.

The beauty behind the science...residual stresses along the interface. (Courtesy @Michal K. Budzik)
Within one of the projects we developed experimental method to study adhesion of structural rubber to stainless steel bonded directly using polymer brushes. What you see is a remaining of the rubber attached to the steel surface after the peel test. The specimen is of 8x8 mm. This path allow us to investigate the adhesion and toughness of rubber. (Courtesy @Michal K. Budzik)

RESEARCH INTERESTS

 

  • Dry adhesion: Inspired by the famous gecko feet. Adhesion control without using an actual adhesive but based on geometry and hierarchy to build suitable load carrying capacity and full bonding reversibility. 
  • Failure in layered materials: Brittle fracture, viscoelastic effects, environmental effects, machining of composite materials.
  • Design and tuning of material properties: Design of crack growth paths by local modifications of surfaces and geometry of components. The approach is directly related to impact of quality of surfaces, interfaces and geometry on load carrying capacities of materials and structures.
  • Crack onset and crack arrest: Material and geometrical nonlinearity effects pre- and post- failure, including crack front pinning-depinning transition studies.

APPLICATIONS

  • Adhesive bonding
  • Composite materials
  • Multimaterials through additive manufacturing
  • Soft materials and reversible adhesion
  • Interfaces under harsh environmental conditions

LABORATORY

The important part of activities is taking place in Laboratory for Mechanics and Physics of Solids located on the 5th floor of Navitas building. More details could be found under the link: eng.au.dk/en/research/laboratory-facilities/laboratory-for-mechanics-and-physics-of-solids/