There are cracks in everything - they provide insight


Advanced computer models of metals that deform in car accidents provide important insights for modern industries

The connection between micromechanical properties and crack growth in metals exposed to permanent plastic deformation has interested Associate Professor Kim Lau Nielsen from DTU Mechanical Engineering for many years. He has now collated much of the knowledge generated in a doctoral dissertation.

"Whether it's the car you drive, the airplane on which you fly, or the ship you board, you expect it to be able to withstand the loads during intended use - and often also during unintentional use. However, such a promise is difficult to keep without insight into plastic deformation and fracture mechanics, as well as the possibility of virtual testing using computer models. My research tries to provide new modelling techniques and new knowledge about fractures in metals,” says Kim Lau Nielsen.

In that perspective, insight into the deformation and fracture of metals can ultimately save lives, points out Kim Lau Nielsen, who in his research has developed new simulation techniques based on observations from experiments on metals.

"It requires fairly efficient computer models and demonstration of their use before they find their way to industrial use, and it is my goal to create that connection"
Kim Lau Nielsen

Aiming for use in industry                   

"Fairly efficient computer models and demonstration of their use are required before they find their way to industrial use, and it is my goal to create that connection," says Kim Lau Nielsen.

His research focuses partly on bringing new plasticity theories with an underdeveloped modelling basis into practical use, and partly on utilizing the new computer models to understand crack propagation in ductile (moldable) metals better.

“Together with national and international collaborators, we have created novel simulation techniques and procedures that act as a bridge between the different scales in fracture mechanics. We have shown how one can convey the micro-mechanics of ductile plate tearing to large-scale practical applications and, in the process, cemented a special crack propagation mode observed when tearing thin ductile metal plates.”

Defends his doctoral dissertation

When Kim Lau Nielsen defends his doctoral dissertation, DTU Provost Rasmus Larsen is chairperson.

“The technical doctorate is DTU's highest academic distinction and is given in recognition that the candidate with the underlying research has taken the research one step further. With his studies of computer models for modelling and analysis of deformation and fractures in metals, Kim Lau Nielsen has created research that has left its mark on the international research world and is of great benefit to Danish production companies. I look forward to the dissertation defense,” says Rasmus Larsen.

Kim Lau Nielsen's defense of the doctoral dissertation "Fracture and Plasticity Across Scales: Methods and Mechanisms" will take place on 11 January 2022 at 2 pm in Glassalen building 101.


Read Kim Lau Nielsen's doctoral dissertation