The release of dry-snow slab avalanches is preceeded by a fracture process within the layered snowpack. For a crack to nucleate in the snowpack weak layer, two conditions must be met simultaneously. On the one hand, the weak layer must be overloaded in terms of stress. On the other hand, the energy release of newly forming cracks must suffice to form new surfaces. Read our publication on the application of this so-called coupled stress and energy criterion to crack nucleation in layered snowpacks.
Modeling layers of snow as simple structural elements provides closed-form expressions for snowpack deformations, weak layer stresses and energy release rates of cracks in the weak layer. Key property is the compliance of the weak layer.
Fracture processes are governed not by one exclusive but by two conditions simultaneously even if one often hides the other. We apply this important discovery of modern fracture mechanics to the initiation of anticracks in the snowpack. The weak layer can only collapse when it is overloaded in terms of stress and the energy release rate of a finite anticrack suffices simultaneously.
At the International Snow Science Workshop 2018 from October 7th to October 12th in Innsbruck, Austria, we presented our model for skier-triggered dry-snow slab avalanche release. Watch the video to learn more.
August 9, 2018
Founded as a collaboration between friends and former co-workers, Philipp Rosendahl and Philipp Weißgraeber, 2φ is dedicated to deliver efficient and easy to use models using state-of-the-art scientific advances in structural design and fracture mechanics.
August 13, 2018
Today we submitted our contribution to the International Snow Science Workshop 2018 (ISSW) in Innsbruck, Austria. As backcountry skiers and fracture mechanists we developed a novel approach to modeling skier-triggered dry-snow slab avalanche release. We will present the model in a talk at ISSW and are preparing a publication in The Cryosphere.
October 14, 2018
We spent the past week in Innsbruck, Austria, attending the International Snow Science Workshop 2018. Our first contact with snow and avalanche professionals from all over the world left us impressed, motivated and excited for applications and further developments of our slab avalanche release model.
October 19, 2018
We are invited to contribute an article to issue #105 of the German-language magazine bergundsteigen. bergundsteigen is concerned with the interaction of humans and mountains with particular focus on risk-management. The december issue will include certain topics from ISSW 2018. As long-term readers of the journal we are very excited about this opportunity.
January 25, 2019
The latest issue of bergundsteigen with our take on weak layer fracture mechanics and many other interesting contributions from ISSW 2018 is online. Take a look at the issue preview or browse the archive.
April 12, 2019
Avalanche risk assessment is crucial for anyone who travels snowcoverd mountains. Touristically developed regions often provide avalanche bulletins, yet, in the majority of mountainous regions no such information is available. We were invited to the 2nd NATO Mountain Worfare Congress in Risk Management in Poljče, Slovenia to present possibilities of risk assessment using physical and mechanical snowpack models – also in remote regions.
May 9, 2019
September 2, 2019
Supported by the Early Career Researcher Grant of the International Arctic Science Committee we traveled to Aussois, France, to dicuss the latest developments and discoveries concerning slab avalanche formation.
Exploiting the typical three-layer adherend-adhesive-adherend assembly of adhesive joints provides a unified model for manifold bonded connection designs.
Requiring the simultaneous satisfaction of both stress and energy conditions yields a powerful criterion for the nucleation of cracks in adhesive layers.
Tailoring the compliance of adhesives along the bondline in adhesive connections reduces stress peaks and increases the effective joint strength.
Using the J-integral a robust experimental method for determining the fracture toughness of hyperelastic adhesives is derived and applied.
