cRacklet, Open Software for spectral boundary integral method

Prof. Jean-François Molinari

An open-source library to simulate the behavior of an interface bounded between two semi-infinite bodies.

Prof. Jean-François Molinari,


cRacklet is a C++ boundary integral library with a python interface, based on a spectral formulation of the dynamic wave equations in two semi-infinite linearly elastic solids. Its implementation is specially tailored for the modeling of dynamic crack/rupture propagation along a planar interface bonding the two half-spaces. The main benefit of this spectral method is a numerical discretization limited to the mid-plane, thereby providing a very fine description of the dynamic rupture processes, unattainable with finite-element or finite-difference schemes. cRacklet is available under the GPL license.

Why Open?

For our laboratory (Computational Solid Mechanics Laboratory, LSMS), the Open-Source philosophy is a necessary part of a scientific software project. The collaborative development allows enforcing a critical view both in terms of implementation and usability. Publicly available open-Source software is indissociable from reproducibility, which is mandatory for good research practice. Giving back to the scientific community the outcome of a project funded by public institutions (FNS, EPFL) is also a strong statement on how we believe public research should be conducted. In addition, we believe that collaboration around Open-Source software can help build a stronger scientific community, by fostering interactions between researchers around the world.

Who benefits?

cRacklet is aimed at researchers interested in interfacial dynamics, ranging from nucleation problems to dynamic propagation of rupture fronts. cRacklet is efficient, accessible, and suited to study a broad class of problems (fracture and friction). Compared to similar software, cRacklet is particularly easy to use thanks to its python interface and its online tutorials. cRacklet is already used outside Switzerland, in Norway (University of Oslo), in the United States of America (University of Illinois at Urbana-Champaign), and in Israel (Weizmann Institute of Science).


Prof. Molinari has always made open source a priority to ensure reproducibility, as well as rigorous and collaborative coding practices. The development of cRacklet started as a collaboration between our lab and the Department of Aerospace Engineering of the University of Illinois at Urbana-Champaign in the United States of America, for the Master thesis of Fabian Barras, in 2012-2013. It has since been continuously developed by PhD students in our lab. The ENAC has been involved via its ENAC-IT4Research project to help improve the continuous integration and the workflow of cRacklet.
The work was supported by the Swiss National Science Foundation and Rothschild Caesarea Foundation. A contributing researcher also benefited from computing resources from the Norwegian e-infrastructure for research and education (UNINETT Sigma2).


Other contributors: Fabian Barras, Philippe H Geubelle, ENAC-IT4R (David Tang)