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New Research Group at AAU Making its Mark

New Research Group at AAU Making its Mark

With four new projects in the space of a few months and explosive growth in membership, the research group ‘CraCS – Cracks in Composite Structures’ is fast becoming a world leader in developing simulation tools for industries like wind turbines and aeronautics. Heading the group are Esben Lindgaard, Associate Professor and Brian Bak, Assistant Professor

Last modified: 18.12.2018

From two to seven members in just two years and four new projects funded in just a few months, activities are in high gear in the newly opened offices where the research group ‘CraCS’ spends their days. In the space of a few years, the group has emerged as a world leader in the development of simulation tools that can predict cracks in composite materials that wind turbine blades and aircraft are made of. In fact, things are going so well that the group will soon run out of space for all their members in their new joint office.

In only five years, AAU research on predicting fatigue cracks in composite structures has gone from being non-existent to putting AAU among the absolute top.

‘It has taken a lot of legwork to get to where we are today because it isn’t easy to obtain project funding without showing a strong track-record,’ says Esben Lindgaard.

Today the group is working with a number of internationally recognised research groups as well as a wide range of international companies including Siemens Gamesa Renewable Energy, Siemens, LM Wind Power, Fraunhofer, SINTEF, and Samtech;

The latter will implement the AAU researchers’ simulation tool, which they jointly developed with researchers from the University of Girona, Spain, in the solution they sell to the end customer.

Holistic research to benefit the industry

The research group CraCS combines areas that are often handled separately, such as research on damage modelling, materials characterisation, and progressive crack development. The holistic approach means that the group's research findings can often be transferred directly to industrial practice, and that is motivating for the researchers. 

‘We are trying to merge all the areas, and it’s very satisfying to see that our research is of practical value to the industry,’ says Brian Bak, an assistant professor in the research group.

He compares the approach to craftsmen building a house together. The greatest chance of success is when the carpenters, electricians, bricklayers, etc., coordinate closely during the process. 

Ph.D. course opened the door for the international research environment

Part of the legwork underlying the successful research group was Esben and then Ph.D. student Brian Bak creating a Ph.D. course that was lacking in Brian's Ph.D. training. It turned out that there was a gap in the market in this area, and this led to them organising the course themselves,

‘which had the secondary effect that the we could break down the door to leading researchers within the field by inviting them to teach in the course.. So we not only built a network but we also used it As a display window for our own research,’ says Esben Lindgaard.

The course has been held three times for more than a total of 100 Ph.D. students from all over the world.

Everything rhymes with synergy and collaboration

Another major reason for the research group's progress is a work method that provides space for everyone in the group. The mantra is that everything has to rhyme with synergy and collaboration, so early this year, the group established a joint office to support this approach. The office was designed for six researchers, and even though it will soon be too small, Esben Lindgaard and Brian Bak insist on cooperation and synergy being paramount.

‘We have often seen the solitary Ph.D. student grinding out their thesis, but we try to avoid that by bringing everyone's competences and ideas into play. And of course it’s also in the spirit of the PBL method,’ says Esben Lindgaard and adds: ‘I think that we go much further when we work closely — even across projects. So we insist on organising ourselves in an open office environment.’

In addition to working in an open office landscape, the group also works with a Kanban board that provides visibility on all project- and research-related tasks. The board also makes it possible to note new research ideas to be discussed and prioritised on an ongoing basis. Besides the professional benefits, the approach also ensures a high level of job satisfaction and trust among the group members.

Focus on ensuring momentum

For the researchers in the group, it was important that the projects they sought funding for complemented each other.

‘We want to work in the same sandbox not only to ensure momentum, but also so that our researchers have a natural interest in getting involved in each other's projects and we can achieve that synergy effect we’re so focused on,’ says Brian Bak.

The group is looking forward to the coming year where new Ph.D. students, postdocs, guest Ph.D. students and a visiting professor will be part of the group. In the long term, the group’s vision is to expand the industrial partnerships to other industries working with composites, such as aerospace, automotive, electronics, and 3D printing.


  • The group’s work deals with predicting cracks in composites using simulation tools. The work describes damage mechanisms using fracture mechanics and damage mechanics with a special focus on cohesive zone models. The tools developed are intended to simulate progressive damage under repeated loading using 3D solid nonlinear finite element models. For materials characterisation, the group has developed special fixtures, loading introduction and totally automated machine vision methods for tracking cracks during testing.
  • Esben Lindgaard is part of the AAU Talent Programme. Learn more here
  • The four projects funded during the spring are:
    • Danish Council for Independent Research | Technology and Production: Fatigue-driven Delamination Considering Real Load Spectra
    • EU H2020: Understanding the Physics of Wind Turbine and Rotor Dynamics through an Integrated Simulation Framework
    • AAU Talent Programme: Fatigue-driven Damage in Laminated Composite Structures
    • Obel Family Foundation: Equipment - Terahertz time domain spectrometer (co-applicant)